A laser welding and laser shot peening integrated composite machining device

Abstract

The application provides a kind of integrated composite processing device of laser welding and laser shot peening, including mobile device, laser welding-shot peening assembly, water tank, water injection system, workbench and control system;The laser welding-shot peening assembly includes laser welding device, mechanical arm clamping assembly and laser shot peening device;The laser welding device and laser shot peening device are installed on the mechanical arm clamping assembly;The mechanical arm clamping assembly is connected with the mobile device, for driving the laser welding device and laser shot peening device to move along the processing surface;An inclined surface of the water tank is provided with a workbench parallel to the inclined surface;The water injection system is used to inject water into the water tank;The control system controls the water injection amount, so that the horizontal surface in the water tank coincides with the laser shot peening processing point.The device can realize the synchronous movement of laser shot peening and laser welding, the water surface and the laser nozzle are synchronously raised, the shot peening efficiency is effectively improved, the weld surface quality after impact is uniform, and the precision requirement is high.

Description

Technical Field

[0001] This invention relates to the field of laser processing, and more particularly to a composite processing device that integrates laser welding and laser shot peening. Background Technology

[0002] In today's fiercely competitive global market, improving industrial efficiency and quality has become a goal pursued by enterprises and nations. Welding plays a crucial role in fields such as automobiles, aerospace, shipbuilding, and electronics. Through welding, metal parts can be assembled into various structures and equipment to meet societal and market demands. Laser welding is a high-precision welding technology that uses a laser beam to weld materials. It boasts advantages such as high energy density, a small heat-affected zone, and fast welding speed. The introduction of laser welding has improved both industrial efficiency and product quality. However, for the entire welded component, the weld joint is the most prone to fracture and failure. The performance of the weld joint directly affects the performance of the entire component. The main failure modes of weld joints include corrosion, fatigue fracture, cracks, and wear. The joint surface is a weak area, and joint failure usually begins at the surface. Therefore, the microstructure and properties of the joint surface directly affect the overall performance of the joint. Laser shot peening is an advanced surface strengthening technology. Laser shot peening can refine the surface grains of metallic materials, causing plastic deformation of the material surface, resulting in an ideal microstructure and residual stress distribution, thus improving the fatigue strength and corrosion resistance of the metallic material. How to perform laser shot peening on the surface of welded joints has received increasing attention and research.

[0003] Currently, research on laser shot peening of welded joint surfaces mainly includes: Existing technologies propose a laser shock peening method for weld surfaces. This method utilizes multiple laser beams converged in multiple directions based on the weld's ripple distribution to strengthen the weld surface without an absorption layer. Existing technologies also propose a combined device for underwater laser welding and shot peening. This technology can be applied to alternating or continuous underwater laser welding and shot peening operations, featuring an ingenious structure and ease of operation. Furthermore, existing technologies propose a laser shock peening method for strengthening and toughening aluminum alloy friction stir welded butt joints. This method uses different laser shock peening parameters to perform laser shock peening on different areas, improving the uniformity of local joint properties, significantly increasing the joint's yield strength, and enhancing the overall elongation of the joint.

[0004] Although the above research has made good progress in laser shot peening of welded joint surfaces, breakthroughs are still needed in the following new areas: Current laser shock peening methods for welded joint surfaces strengthen the joint surface after the welded joint is formed. In this case, the metal welded joint is prone to forming an oxide layer, requiring pretreatment before laser shot peening, which increases the number of steps and reduces production efficiency; Currently, most laser shot peening of welded joints does not use an absorption layer and a constraint layer, which results in uneven weld surface quality and reduced precision after impact. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a composite processing device integrating laser welding and laser shot peening. The laser welding device and the laser shot peening device are mounted together on a robotic arm clamping assembly, enabling synchronous movement of both. Two spray guns are added between the laser welding and shot peening devices. The upper spray gun sprays black paint onto the unpeened weld as an absorption layer, while the lower spray gun sprays water to wash away impurities from the weld surface. The water flows into a water tank on the left. The control system controls the water injection system based on the moving speed of the device and the tilt angle of the worktable, ensuring the water level in the tank just covers the shot peening point, acting as a constraint layer for laser shot peening. The water level rises synchronously with the laser shot peening point, achieving uniform weld surface quality and high precision after impact. Furthermore, a water recycling device is incorporated, allowing for the recycling of water used in this process.

[0006] The present invention achieves the above-mentioned technical objectives through the following technical means.

[0007] A composite processing device integrating laser welding and laser shot peening includes a moving device, a laser welding-shot peening assembly, a water tank, a water injection system, a worktable, and a control system.

[0008] The laser welding-shot peening assembly includes a laser welding device, a robotic arm clamping assembly, and a laser shot peening device; the laser welding device and the laser shot peening device are mounted on the robotic arm clamping assembly; the robotic arm clamping assembly is connected to a moving device for driving the laser welding device and the laser shot peening device to move along the processing surface;

[0009] A worktable parallel to the inclined surface is provided on one of the inclined surfaces of the water tank, and the workpiece to be processed is placed on the worktable; the water injection system is used to inject water into the water tank;

[0010] The control system controls the water injection volume of the water injection system according to the parameters of the mobile device, so as to make the horizontal plane in the water tank coincide with the processing point of the laser shot peening device.

[0011] Furthermore, a protective gas output device is installed at the front end of the laser welding device to provide protective gas during the welding process.

[0012] Furthermore, a black paint spraying tube is installed between the laser shot peening device and the laser welding device to spray a black absorption layer onto the weld surface.

[0013] Furthermore, the water injection system includes a water inlet, a water pump, and a water storage tank; the water inlet is located between the laser shot peening device and the laser welding device; the water tank, water storage tank, water pump, and water inlet form a closed loop; the water inlet is aligned with the weld surface to remove impurities and form a constraint layer on the weld surface.

[0014] Furthermore, the integrated laser welding and laser shot peening composite processing device is also equipped with a wastewater treatment device, which is located between the water tank and the water storage tank to filter out residues in the wastewater.

[0015] A processing method for a composite processing device integrating laser welding and laser shot peening includes the following steps:

[0016] The distance between the laser welding device and the laser shot peening device is s, and the processing position corresponding to the laser welding device is the welding initial point.

[0017] The mobile device drives the laser welding device to start welding at the initial welding point. During the welding process, the protective gas output device outputs protective gas. At the same time, the water injection system controls the amount of water injected into the water tank according to the speed and spacing s of the mobile device.

[0018] The black paint spraying nozzle sprays a black absorbent layer onto the surface of the welded seam;

[0019] When the laser shot peening device reaches the initial welding point, the horizontal plane in the water tank coincides with the initial welding point, and the laser shot peening device performs shot peening on the weld. The water injection system controls the amount of water injected into the water tank according to the speed of the moving device and the angle of inclination of the water tank, so that the horizontal plane in the water tank coincides with the processing point of the laser shot peening device.

[0020] Furthermore, the control system controls the water injection flow rate q of the water injection system to uniformly inject water into the water tank based on the speed and distance s of the moving device, specifically as follows:

[0021] The uniform injection flow rate q at time t is:

[0022]

[0023] In the formula: T1 is the time it takes for the laser shot peening device to move to the initial welding point B. s is the distance between the laser welding device and the laser shot peening device; v is the movement speed of the robotic arm driving the laser welding device; m is the horizontal distance between the initial welding point B and the wall of the water tank; l is the length of the pre-processed workpiece; α° is the angle between the worktable and the ground; c is the width of the water tank.

[0024] Furthermore, the control system controls the water injection flow rate q of the water injection system to accelerate water injection into the water tank based on the speed of the moving device and the tilt angle of the water tank. (t) Specifically:

[0025] Water injection flow rate q at time t (t) for:

[0026] q (t) =sinα·c·v·[v·(t-T1)·cosα+m](T1<t≤T1+T2)

[0027] T2 is the time it takes for the laser shot peening device to process the workpiece from the initial welding point B.

[0028] The beneficial effects of this invention are as follows:

[0029] 1. The laser welding and laser shot peening integrated composite processing device of the present invention clamps the laser welding device and the laser shot peening device together through a robotic arm clamping assembly, thereby realizing the synchronous movement of the laser welding device and the laser shot peening device.

[0030] 2. The integrated laser welding and laser shot peening composite processing device of the present invention controls the water injection speed so that the water surface in the water tank always just covers the shot peening point during laser shot peening, serving as a constraint layer for laser shot peening. The water surface and the laser shot peening point rise synchronously, effectively improving shot peening efficiency and achieving the requirements of uniform weld surface quality and high precision after impact.

[0031] 3. The integrated laser welding and laser shot peening composite processing device of the present invention filters the process water that has already been used by setting up a wastewater treatment device, and the treated water can be recycled. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are some embodiments of the present invention. For those skilled in the art, it is obvious that other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the integrated laser welding and laser shot peening composite processing device described in this invention.

[0034] Figure 2 This is a schematic diagram of the water tank structure described in this invention;

[0035] Figure 3 This is a schematic diagram of the water outlet velocity in the first stage of the water inlet as described in this invention;

[0036] Figure 4 This is a schematic diagram of the water outlet velocity in the second stage of the water inlet as described in this invention;

[0037] Figure 5 This is a flowchart of the integrated laser welding and laser shot peening composite processing device described in this invention.

[0038] In the picture:

[0039] 1. Robotic arm; 2. Robotic arm clamping assembly; 3. Water pipe and fiber optic inlet; 4. Laser welding device; 5. Laser shot peening device; 6. Shielding gas output device; 7. Black paint spray pipe; 8. Water inlet; 9. Worktable; 10. Fixture; 11. Water tank; 12. Drain outlet; 13. Sewage treatment device; 14. Water storage tank; 15. Water pump; B. Welding starting point; C. Welding ending point. Detailed Implementation

[0040] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0041] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "axial," "radial," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0042] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] like Figure 1 As shown, the integrated laser welding and laser shot peening processing device of the present invention includes a moving device, a laser welding-shot peening assembly, a water tank 11, a water injection system, a worktable 9, and a control system. The laser welding-shot peening assembly includes a laser welding device 4, a robotic arm clamping assembly 2, and a laser shot peening device 5. The laser welding device 4 and the laser shot peening device 5 are mounted on the robotic arm clamping assembly 2, and the interval between the laser welding device 4 and the laser shot peening device 5 is s. The robotic arm clamping assembly 2 is connected to the moving device and is used to drive the laser welding device 4 and the laser shot peening device 5 to move along the processing surface. The moving device is a robotic arm 1, which consists of two mutually perpendicular horizontal arms and vertical arms. It is equipped with two servo motors. One servo motor is used to drive the horizontal arm to move at a constant speed parallel to the worktable 9, and is used to adjust the working position of the laser welding-shot peening assembly on the surface of the pre-processed workpiece. The other servo motor is used to drive the vertical arm to move up and down perpendicular to the worktable 9, and is used to adjust the height of the laser welding-shot peening assembly.

[0044] like Figure 2 As shown, the water tank 11 consists of a vertical surface and an inclined surface. A worktable 9 parallel to the inclined surface is provided on one inclined surface of the water tank 11. The workpiece to be processed is placed on the worktable 9. The installation angle of the laser welding device 4 and the laser shot peening device 5 on the robotic arm mounting assembly 2 is consistent with the inclination angle of the inclined surface of the water tank 11. The water injection system is used to inject water into the water tank 11. The water injection is divided into two stages. The process from the start of water injection to the horizontal surface in the water tank 11 reaching the initial welding point B is the first water injection stage, which is a uniform water injection. The process from the start of shot peening by the laser shot peening device 5 to the end point C of the welding process and the completion of shot peening is the second water injection stage, which is an accelerated water injection. The control system controls the water injection volume of the water injection system according to the parameters of the moving device to ensure that the water surface in the water tank 11 always just covers the shot peening point during the shot peening process.

[0045] The water injection system includes a water inlet 8, a water pump 15, and a water storage tank 14; the water inlet 8 is located between the laser shot peening device 5 and the laser welding device 4; the water tank 11, the water storage tank 14, the water pump 15, and the water inlet 8 form a closed loop; the water inlet 8 is aligned with the weld surface to remove impurities and form a constraint layer on the weld surface; a sewage treatment device 13 is also provided between the water tank 11 and the water storage tank 14, and the sewage treatment device 13 is equipped with a filter device for filtering residues in the wastewater.

[0046] Example:

[0047] like Figure 1 As shown, the pre-processed workpiece is fixed on the inclined worktable surface 9 by the clamp 10. Driven by a servo motor, the position of the robotic arm 1 is adjusted so that the laser welding head of the laser welding device 4 is directly above the initial welding point B of the pre-processed workpiece. Signals are transmitted from the water pipe and fiber optic inlet 3, activating the laser welding device 4. During welding, the protective gas output device 6 provides protective gas, creating a suitable environment for laser welding and preventing oxygen and other impurities from contaminating the weld. In this device, the protective gas is Ar gas. The black paint spray pipe 7 sprays a black absorbing layer onto the weld surface, reducing laser reflection from the workpiece surface and increasing laser utilization, while also protecting the workpiece surface quality for a better surface morphology. The first stage of water injection also begins simultaneously with the start of welding. The first stage involves uniform water injection, with a constant water flow rate q per unit time. Water pump 15 draws water from reservoir 14 and, through a water pipe connection, sprays water from injection port 8. The sprayed water is used to clean the weld surface after painting, removing surface impurities. The control system controls the water injection volume of the water injection system according to the parameters of the moving device, ensuring that when the laser shot peening device 5 reaches the initial welding position B, the horizontal plane in the water tank 11 coincides with the initial welding position B. When the laser shot peening device 5 reaches the initial welding position B, shot peening begins. At this time, the control system controls the water injection system to accelerate water injection. The water injection system controls the water injection volume in the water tank 11 according to the speed of the moving device, the tilt angle of the water tank 11, and the movement distance, ensuring that the horizontal plane in the water tank 11 always coincides with the shot peening point at every moment during the shot peening process.

[0048] When the laser welding device 4 reaches the welding endpoint C and completes the welding work, the robotic arm 1 continues to move at a constant speed, and the laser shot peening device 5 continues to perform shot peening until the laser shot peening device 5 reaches the welding endpoint C and completes the shot peening process. At this time, the welding-shot peening process is completed. The laser welding device 4, the laser shot peening device 5, the protective gas output device 6, the black paint spray pipe 7, and the water inlet 8 are all in the closed state. The drain outlet 12 at the lower end of the water tank 11 is opened, and the water in the water tank 11 is discharged into the sewage treatment device 13 through the drain outlet 12. The sewage treatment device 13 filters out the residue in the wastewater and stores the treated water in the water storage tank 14 for use in the next operation.

[0049] like Figure 5 As shown, the specific processing method of the integrated laser welding and laser shot peening composite processing device proposed in this invention is as follows:

[0050] S01: The laser welding device 4 starts welding at the initial welding point B. During the welding process, the protective gas output device 6 outputs protective gas. In this invention, the protective gas is Ar gas. At the same time, the robotic arm 1 moves at a constant speed parallel to the worktable 9, driving the laser welding device 4 and the laser shot peening device 5 to move synchronously. The water pump 15 draws water from the water storage tank 14, connects it through a water pipe, and sprays the water out through the water inlet 8 to uniformly fill the water tank 11. When the laser shot peening device 5 reaches the initial welding position B, the water level in the water tank 11 also coincides with the initial welding position B, and the uniform water filling stage ends.

[0051] like Figure 3 As shown, the straight-line distance between the initial position of the laser welding device 4 and the laser shot peening device 5 is s, the movement speed of the robotic arm 1 is v, the horizontal distance between the initial welding point B and the wall of the water tank 11 is m, the length of the pre-processed workpiece is l, and the angle between the worktable and the ground is α°.

[0052] During the uniform water injection stage, when the laser shot peening device 5 starts from point A and moves to the initial welding point B, the running time T1 is:

[0053]

[0054] The total water injection volume V during the uniform water injection phase is:

[0055]

[0056] The injection flow rate q at time t during the uniform injection phase is:

[0057]

[0058] S02: Black paint spraying pipe 7 sprays a black absorbing layer onto the surface of the welded seam;

[0059] S03: Driven by the robotic arm 1, the laser welding device 4 and the laser shot peening device 5 move at a constant speed along the parallel worktable 9. When the laser shot peening device 5 moves to the initial welding point B, the water level in the water tank 11 just reaches the initial welding point B. The laser shot peening device 5 starts shot peening, and the water inlet 8 starts to accelerate water injection.

[0060] like Figure 4 As shown, the water injection system starts to accelerate the water injection. The water injection system controls the amount of water injected into the water tank 11 according to the speed v of the moving device, the tilt angle of the water tank 11 and the movement distance l, so that the horizontal plane in the water tank 11 coincides with the processing point of the laser shot peening device 5.

[0061] During the accelerated water injection phase, the laser shot peening device 5 moves from the initial welding point B to the final welding point C. The travel time T2 is:

[0062]

[0063] The water volume V in the tank at time t during the accelerated water injection phase (t) :

[0064]

[0065] During the accelerated water injection phase, the water volume V in the tank at time t+Δt is... (t+△t) (△t→0):

[0066]

[0067] The water injection flow rate q at time t during the accelerated water injection phase (t) for:

[0068]

[0069] q (t) =sinα·c·v·[v·(t-T1)·cosα+m](T1<t≤T1+T2)

[0070] In the formula: T1 is the time it takes for the laser shot peening device 5 to move to the initial welding point B. s is the distance between the laser welding device and the laser shot peening device; v is the movement speed of the robotic arm 1 driving the laser welding device 4; m is the horizontal distance between the initial welding point B and the wall of the water tank 11; l is the length of the pre-processed workpiece; α° is the angle between the worktable and the ground; c is the width of the water tank 11; T2 is the running time of the laser shot peening device 5 from the initial welding point B to process the workpiece.

[0071] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0072] The detailed descriptions listed above are merely specific illustrations of feasible embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A composite processing device integrating laser welding and laser shot peening, characterized in that, Includes a mobile device, a laser welding-shot peening assembly, a water tank (11), a water injection system, a worktable (9), and a control system; The laser welding-shot peening assembly includes a laser welding device (4), a robotic arm clamping assembly (2), and a laser shot peening device (5); the laser welding device (4) and the laser shot peening device (5) are mounted on the robotic arm clamping assembly (2); the robotic arm clamping assembly (2) is connected to a moving device to drive the laser welding device (4) and the laser shot peening device (5) to move along the processing surface; The water tank (11) has a worktable (9) parallel to the inclined surface on one of its inclined surfaces. The workpiece to be processed is placed on the worktable (9) with its processing surface parallel to the worktable. The water injection system is used to inject water into the water tank (11). The control system controls the water injection volume of the water injection system according to the parameters of the mobile device. After the shot peening process begins, the horizontal plane in the water tank (11) coincides with the processing point of the laser shot peening device (5), ensuring that the water surface in the water tank always just covers the shot peening point during the shot peening process.

2. The integrated laser welding and laser shot peening composite processing device according to claim 1, characterized in that, The laser welding device (4) is equipped with a protective gas output device (6) at its front end, which is used to provide protective gas during the welding process.

3. The integrated laser welding and laser shot peening composite processing device according to claim 1, characterized in that, A black paint spraying pipe (7) is installed between the laser shot peening device (5) and the laser welding device (4) for spraying a black absorption layer onto the weld surface.

4. The integrated laser welding and laser shot peening composite processing device according to claim 1, characterized in that, The water injection system includes a water inlet (8), a water pump (15), and a water storage tank (14); the water inlet (8) is located between the laser shot peening device (5) and the laser welding device (4); the water tank (11), the water storage tank (14), the water pump (15), and the water inlet (8) form a closed loop; the water inlet (8) is aligned with the weld surface to remove impurities and form a constraint layer on the weld surface.

5. The integrated laser welding and laser shot peening composite processing device according to claim 4, characterized in that, It is also equipped with a sewage treatment device (13), which is located between the water tank (11) and the water storage tank (14) to filter the residue in the wastewater.

6. A processing method for a composite processing device integrating laser welding and laser shot peening according to any one of claims 1-5, characterized in that, Includes the following steps: The distance between the laser welding device (4) and the laser shot peening device (5) is s, and the processing position corresponding to the laser welding device (4) is the welding initial point B; The mobile device drives the laser welding device (4) to start welding at the initial welding point B. During the welding process, the protective gas output device (6) outputs protective gas. At the same time, the control system controls the water injection system to inject water into the water tank (11) at a uniform speed according to the speed v and spacing s of the mobile device. The black paint spraying pipe (7) sprays a black absorbing layer onto the surface of the welded seam; When the laser shot peening device (5) reaches the initial welding point B, the horizontal plane in the water tank (11) coincides with the initial welding point B, and the laser shot peening device (5) performs shot peening on the weld. The control system controls the water injection system to accelerate the injection of water into the water tank (11) according to the speed of the moving device and the angle of the inclined surface of the water tank (11), so that the horizontal plane in the water tank (11) coincides with the processing point of the laser shot peening device (5).

7. The processing method of the integrated laser welding and laser shot peening composite processing device according to claim 6, characterized in that, The control system controls the water injection flow rate q of the water injection system into the water tank (11) at a uniform speed according to the speed and spacing s of the moving device, specifically as follows: The uniform injection flow rate q at time t is: ， In the formula: T1 is the time it takes for the laser shot peening device (5) to move to the initial welding point B: ; s is the distance between the laser welding device (4) and the laser shot peening device (5); v is the movement speed of the laser welding device (4) driven by the robotic arm (1); m is the horizontal distance between the initial welding point B and the wall of the water tank (11); α is the angle between the workbench and the ground; c is the width of the water tank (11).

8. The processing method of the integrated laser welding and laser shot peening composite processing device according to claim 7, characterized in that, The control system controls the water injection flow rate of the water injection system to accelerate water injection into the water tank (11) based on the speed of the moving device and the tilt angle of the water tank (11). Specifically: Water flow rate at any time for: ， T2 is the running time of the laser shot peening device (5) from the initial welding point B to process the workpiece: ; l represents the length of the pre-processed workpiece.

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