Laser positioning / welding and laser cleaning synchronous integrated equipment and method

Abstract

The invention discloses laser positioning / welding and laser cleaning synchronous integrated equipment and a laser positioning / welding and laser cleaning synchronous integrated method. The equipment realizes real-time positioning and automatic focusing based on welding seam tracking and optical signal processing, links two lasers to synchronously emit welding and cleaning light beams, acts on a welding pool at the same time, and is matched with shielding gas pre-injection, smoke discharge and slag removal and a special clamp to remove impurities in the welding pool in real time, generate micro-vibration stirring and promote grain refinement in the welding process. According to the equipment, key links such as workpiece clamping and positioning, automatic focusing, welding and cleaning are combined, the technological process is greatly simplified, and the compactness and the mechanical property of a welding seam of a plated part are improved.

Description

[0001] Technical field: The present invention relates to a laser welding system, specifically a laser welding and laser cleaning synchronous operation welding system, belonging to the field of laser welding technology.

[0002] Background: With increasing demands for lightweighting and weld reliability, coated components are widely used in vehicle bodies and building structures. Laser welding, with its high energy density, deep penetration, and precise heat input, has become the primary welding method for coated components, achieving a narrow heat-affected zone and consistent weld quality.

[0003] However, during welding, the coating easily melts into the molten pool and alloy element segregation occurs, resulting in uneven composition and increased crack sensitivity, and easy brittleness or cracking after cooling; slag and oxides will also adhere to the edges, resulting in pores, slag inclusions and spatter deposition, reducing the density and mechanical properties of the weld.

[0004] The currently common offline process of "clean before welding" suffers from secondary contamination and inadequate dynamic cleaning. This makes it difficult to remove contaminants in real time during molten pool formation and solidification. This can easily lead to the formation of brittle phases during welding, increasing crack sensitivity and impacting welding performance. Consequently, a simultaneous online laser welding and laser cleaning technology is urgently needed to improve weld performance and simplify the production process.

[0005] Invention Summary: To improve the quality and efficiency of laser welds on coated parts, this invention proposes an integrated laser positioning / welding and laser cleaning device and method. This device removes defects such as oxides, spatter, and slag generated during welding, while simultaneously refining grain size, reducing weld segregation and crack sensitivity. It is suitable for welding a wide range of materials and significantly improves weld density and mechanical properties.

[0006] The present invention adopts the following technical solutions: A laser positioning / welding and laser cleaning synchronous integrated equipment for plated parts, including a control system, a first laser generator, a second laser generator, a laser weld tracking system, an optical signal processor, a welding protective gas system, a smoke exhaust and slag cleaning system and a fixture assembly.

[0007] Among them, the laser weld tracking system includes a laser scanning device and a data acquisition module, which are used to scan the area to be welded in real time and transmit the scanning signal to the optical signal processor; the optical signal processor calculates and issues the focal length and power control instructions of the two laser generators according to the process of "first analyzing the signal → automatic focus → starting the laser", and automatically adjusts the focal length through the automatic focus mechanism integrated in the welding heat source and cleaning nozzle before emitting the laser; the first laser generator is integrated with the welding heat source to emit a high-power welding beam; the second laser generator is integrated with the cleaning output nozzle to emit a cleaning beam to instantly remove the oxide layer and spatter when the molten pool is initially formed, and produce a micron-level stirring effect; the welding shielding gas system sprays inert gas through the shielding gas output pipeline before welding to form a stable protective atmosphere; the smoke and slag removal system synchronously starts the smoke and slag removal device through the inert gas cylinder and the diversion pipeline, and removes smoke and slag in real time with a high-speed inert gas flow; the fixture assembly actively positions and hydraulically clamps the plates or pipes in the vertical, horizontal and azimuth directions.

[0008] The present invention also adopts the following technical solution: a laser positioning / welding and laser cleaning integrated welding method for plated parts: S1: Place the workpiece to be welded on the fixture assembly, start the lower slide rail slider (92) of the workbench to position the length, and after locking, start the upper rotation mechanism (91) to position the angle; then sequentially drive the vertical hydraulic cylinder (93) to complete the height positioning, the horizontal telescopic hydraulic cylinder (96) to complete the width positioning, selectively start the support arm hydraulic cylinder (99) to support the V-shaped support arm (910), and start the horizontal telescopic hydraulic cylinder (96) to apply lateral clamping to the workpiece; S2: The control system (1) starts the optical signal processor (6) to analyze the scanning signal of the laser weld tracking system (5); S3: The optical signal processor (6) calculates and outputs control instructions to drive the first laser generator (2) and the second laser generator (3) to automatically adjust the focal length when emitting the welding beam and the cleaning beam respectively; S4: The welding shielding gas system (7) triggers the shielding gas supply device in advance to perform pre-spraying; S5: During the welding / cleaning process, the smoke exhaust and slag removal system (4) is started synchronously to remove smoke and residue through the smoke exhaust and slag removal device output head (12); S6: When welding is completed and the end signal is detected, the laser generator (2, 3) is turned off, the clamps are released in sequence and the workpiece is removed.

[0009] The present invention has the following advantages: 1. Micro-vibration stirring of the molten pool, grain refinement, and performance improvement: Laser cleaning produces micron-level vibration stirring on the molten pool in different modes, which can break up primary grains, optimize grain growth direction, reduce segregation, refine the microstructure, and improve crack sensitivity; thereby significantly improving the mechanical properties, crack resistance, and fatigue life of the weld.

[0010] 2. Welding and laser cleaning are synchronized to remove impurities in the molten pool: Under the synchronous control of welding and cleaning, the welding beam and the cleaning beam are closely connected, which can immediately remove the oxide layer and spatter as soon as the molten pool is formed; the cleaning beam has good adsorption and removal capabilities for the oxide layer on the surface and edge of the molten pool without damaging the base metal, significantly improving the density and bonding strength of the weld.

[0011] 3. Surface forming and cleaning are integrated, simplifying the process flow: The optical signal processing system dynamically optimizes the focal length and power of the laser welding heat source and cleaning nozzle based on the real-time scanning signal of the laser weld tracking system, achieving simultaneous contour forming and cleaning without the need for subsequent mechanical grinding or polishing. Laser welding and cleaning are performed in parallel to adapt to different curved surfaces and joint shapes, completing forming and cleaning in one step, simplifying the production process.

[0012] 4. Dual protection of shielding gas and slag removal, high reliability: The welding shielding gas system pre-sprays inert gas 5-10 seconds before welding to form a stable protective atmosphere. At the same time, the fume exhaust and slag removal system operates synchronously with the welding / cleaning process, removing smoke and residue in real time through the output head, effectively suppressing high-temperature oxidation and secondary damage, further improving weld quality and surface integrity. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a system diagram of an integrated laser positioning / welding and laser cleaning equipment for coated parts, where 1-control system; 2-first laser generator; 3-second laser generator; 4-smoke exhaust and slag cleaning system; 5-laser weld seam tracking system; 6-optical signal processing system; 7-welding shielding gas system; 8-optical signal sensor; 9-welding fixture; 10-moving slider system; 11-chute; 12-smoke exhaust and slag cleaning device output head; 13-laser cleaning output nozzle with autofocus; 14-laser welding heat source with autofocus; 15-shielding gas output copper tube; 16-hydraulic cylinder and vertical support; 17-lockable horizontal rotating slider; 18-base; 19-traction rope Figure 2 This is a welding fixture diagram, where 90 is the base plate; 91 is the rotating mechanism; 92 is the lower slide block; 93 is the vertical hydraulic cylinder; 94 is the vertical support; 95 is the slide block; 96 is the horizontal telescopic hydraulic cylinder; 97 is the telescopic crossbeam body (horizontal clamping arm); 98 is the support arm storage slot; 99 is the support arm hydraulic cylinder; 910 is the V-shaped support arm; 911 is the support arm hinge assembly; 912 is the support arm anti-slip and anti-pressure pad Figure 3 This is a welding process diagram, where 20 is the welding completion area; 21 is the welding pool; 22 is the base material Figure 4 This is a schematic diagram of the slow welding process, where 23-laser cleaning area Figure 5 Schematic diagram of the rapid welding process. DETAILED DESCRIPTION

[0014] The following is a detailed description of the embodiment of the present invention "an integrated laser positioning / welding and laser cleaning device" with reference to the accompanying drawings: The plate-coated part to be welded is clamped on the welding fixture (9), and three-dimensional positioning and clamping are achieved through the coordinated action of the lower slide rail slider (92), the rotating mechanism (91), the vertical hydraulic cylinder (93), the horizontal telescopic hydraulic cylinder (96) and the telescopic crossbeam body (97). Then, the control system (1) is started, and the optical signal sensor (8) scans and records the weld position length, which is processed by the weld tracking system (5) and transmitted to the optical signal processing system (6) for analysis and adjustment of the focal length. At the same time, the control system (1) turns on the first laser generator (2) and the second laser generator (3), inputs the welding parameters, and outputs the laser through (13) (14) under the joint action of the optical signal processing system. The moving slider system (10) is synchronously started according to the pre-set welding parameters, and the shielding gas supply system (7) and the smoke exhaust and slag removal system (4) are triggered at the same time. In slow welding mode, the laser welding molten pool presents a circular shape. At the same time, the second laser generator performs a closed rectangular scan in the area according to the set parameter pulse frequency, and reciprocates along the rear half of the length of the molten pool to ensure the full removal of oxides and molten pool impurities. The smoke exhaust and slag cleaning system is started simultaneously, and the smoke and residue generated during the cleaning laser scanning process are sucked away in real time to avoid affecting the subsequent welds. Figure 4 At the end of the last weld, the ranging beam generates a sudden change signal, and the control system shuts down the first and second laser generators and the gas source, releases the fixture lock, removes the weldment, and completes the flat plate processing cycle.

[0015] An integrated laser positioning / welding and laser cleaning device for coated parts, with specific implementation steps: for longitudinal weld seam welding of cylindrical materials, place them on a V-shaped support arm (910) supported by a lower support arm hydraulic cylinder (99), then align the pipe with the center by a vertical hydraulic cylinder (93) and a horizontal telescopic hydraulic cylinder (97) and clamp them, and finally, the upper V-shaped support arm hydraulic cylinder (99) supports a pair of V-shaped support arms (910), and uses a non-slip pad (912) to evenly clamp the pipe wall laterally; in the rapid welding mode, the laser welding molten pool presents an elliptical shape; at the same time, the second laser generator performs a closed rectangular scan in the area according to the set parameter pulse frequency, and reciprocates along the rear half of the length of the molten pool to ensure that the oxides and impurities in the molten pool are fully removed; the smoke exhaust and slag cleaning system is started simultaneously, and the smoke and residue generated during the cleaning laser scanning process are sucked away in real time to avoid affecting the subsequent welds. See the distribution of the welding and cleaning molten pool areas for details. Figure 5 At the end of the last weld, the ranging beam generates a sudden change signal, and the control system shuts down the first and second laser generators and the gas source, releases the fixture lock, removes the weldment, and completes the longitudinal weld processing cycle of the columnar part.

Claims

1. An integrated laser positioning / welding and laser cleaning device for plated parts, characterized in that: include: A control system (1) is provided, which integrates an optical signal processor (6), a first laser generator (2) and a second laser generator (3), and first analyzes the optical signal of the area to be welded and then starts the laser generator; the first laser generator (2) is integrated with a welding heat source (14) to form an automatically focusable laser welding heat source for emitting a welding laser beam; the second laser generator (3) is integrated with a cleaning output nozzle (13) to form an automatically focusable laser cleaning output nozzle for emitting a cleaning laser beam; a laser weld tracking system (5) is used to scan the area to be welded in real time and transmit the scanning signal to the optical signal processor (6); the optical signal processor (6) receives and processes the signal from the laser weld tracking system (5), calculates and outputs a control instruction according to the required focal length and power parameters, and drives the first laser generator (2) and the second laser generator (3) respectively automatically adjust the focal length through their automatic focusing mechanisms (14, 13) and then emit lasers; a welding shielding gas system (7), including a shielding gas output copper tube (15) and a nozzle, is used to pre-spray inert gas before the welding process begins; a smoke exhaust and slag cleaning system (4), including an inert gas cylinder, a guide pipe and a smoke exhaust and slag cleaning device output head (12), is started synchronously with the first laser generator (2) and the second laser generator (3), and is used to spray inert high-speed airflow into the weld area and remove smoke and dust when welding / cleaning are carried out simultaneously; wherein, the control system (1) follows the process of "first analyzing the signal and then automatically focusing and starting the laser" to ensure that the nozzle (13) and the welding heat source (14) are accurately focused, and the smoke exhaust and slag cleaning system (4) operates synchronously with the welding and cleaning processes.

2. The device according to claim 1, characterized in that The laser weld tracking system (5) is composed of a laser ranging scanning head, an optical signal sensor (8) and a signal processing unit. The ranging scanning head is based on the principle of laser triangulation and scans a linear ranging light beam along the surface of the area to be welded in real time through a galvanometer. The optical signal sensor (8) is a CCD / CMOS camera and is used to collect the reflected spot signal of the ranging light beam on the surface of the workpiece. The signal processing unit receives and analyzes the reflected spot signal of the optical signal sensor (8), extracts the weld position and focal length deviation information, and transmits the information to the optical signal processor (6) to adjust the output power and focal position of the first laser generator (2) and the welding heat source (14) in real time, thereby realizing dynamic tracking and automatic focusing of the weld.

3. The device according to claim 1, characterized in that The optical signal processor (6) includes a signal receiving module, an analysis module and a control module. The signal receiving module receives the scanning signal of the laser weld tracking system (5). The analysis module calculates the optimal focusing parameter. The control module drives the laser cleaning output nozzle (13) and the laser welding heat source (14) to automatically adjust the focal length according to the parameter.

4. The device according to claim 1, characterized in that The auto-focusable laser cleaning output nozzle (13) comprises: a) a beam shaping and energy closed-loop adjustment module; b) a dual-axis galvanometer scanning head and an f-θ focusing lens group; the galvanometer scanning head can scan the surface of the cleaning area in linear reciprocating, figure-8, spiral, contour tracking and composite modes.

5. The device according to claim 1, characterized in that The welding shielding gas system (7) triggers the shielding gas supply device (7) through the shielding gas pre-spray control unit 5-10 seconds before the first laser generator (2) outputs the welding beam to ensure a stable atmosphere in the welding area.

6. The device according to claim 1, characterized in that The device also includes a fixture assembly for three-dimensional active positioning and clamping of the longitudinal welds of rectangular plates and columnar parts during welding / cleaning; the fixture assembly includes: a base plate (90) for carrying the entire fixture assembly and the welded plate or column; a rotating mechanism (91) installed under the base plate (90) and capable of rotating 360 degrees and locking to achieve angle locking; a lower slide block (92) for positioning the workpiece in the longitudinal direction through the cooperation of two sets of fixtures; the vertical pillar (94) is fixed to both ends of the base plate (90), and a vertical hydraulic cylinder (93) is provided at the lower part for driving the upper slide block (95) to move up and down in the Y direction; a top vertical slide block (95) can be moved vertically and locked; a horizontal telescopic hydraulic cylinder (96) connecting the slide block (95) and the telescopic beam (97) for positioning in the X direction and clamping the workpiece laterally, and for driving the beam to extend or retract in the horizontal direction; a telescopic beam body (97) ), a horizontally retractable main bearing beam, a support arm receiving groove (98) is provided on the beam body for receiving the V-shaped support arm in the retracted state; a support arm hydraulic cylinder (99) is installed at one end of the telescopic beam (97) for supporting or retracting a pair of V-shaped support arms; a V-shaped support arm (910) is hinged to the output end of the support arm hydraulic cylinder (99) for supporting the workpiece upward or downward; a support arm hinge assembly (911) adopts a spherical hinge with upper and lower thrust washers, is arranged between the V-shaped support arm (910) and the mounting seat, and is used to bear radial and axial loads and ensure smooth rotation of the support arm; a support arm anti-slip and anti-pressure pad (912) is fixed to the contact surface between the V-shaped support arm (910) and the workpiece to prevent sliding or crushing; wherein the clamp assembly forms three-dimensional active positioning and clamping in the X direction (hydraulic cylinder 96), the Y direction (hydraulic cylinder 93), the support arm opening and closing angle (hinge assembly 911) and the azimuth angle (rotating mechanism 91).

7. The integrated laser positioning / welding and laser cleaning equipment according to claim 1, characterized in that: The laser cleaning range operates on the rear half of the weld pool, and the width and length of the cleaning scan area dynamically adjust with the size of the weld pool to consistently cover the rear half. In slow welding mode, the cleaning scan area essentially overlaps the length of the rear half of the weld pool, performing a closed scan along the rear half of the weld pool. In fast welding mode, the cleaning scan area is still limited to the rear half of the weld pool, but the scan area is slightly larger than in slow welding mode.

8. A laser positioning / welding and laser cleaning integrated method, characterized in that: The following steps are involved: S1: Place the workpiece to be welded on the fixture assembly, pre-coat the surface of the workpiece with a layer of liquid film (deionized water or a specific solvent), start the lower slide rail slider (92) of the workbench to position the length, and after locking, start the upper rotation mechanism (91) to position the angle; then sequentially drive the vertical hydraulic cylinder (93) to complete the height positioning, the horizontal telescopic hydraulic cylinder (96) to complete the width positioning, selectively start the support arm hydraulic cylinder (99) to support the V-shaped support arm (910), and start the horizontal telescopic hydraulic cylinder (97) to apply lateral clamping to the workpiece; S2: The control system (1) starts the optical signal processor (6) to analyze the scanning signal of the laser weld tracking system (5); S3: The optical signal processor (6) calculates and outputs control instructions to drive the first laser generator (2) and the second laser generator (3) to automatically adjust the focal length when emitting the welding beam and the cleaning beam respectively; S4: The welding shielding gas system (7) triggers the shielding gas supply device in advance to perform pre-spraying; S5: During the welding / cleaning process, the smoke exhaust and slag removal system (4) is started synchronously to remove smoke and residue through the smoke exhaust and slag removal device output head (12); S6: When welding is completed and the end signal is detected, the laser generator (2, 3) is turned off, the clamps are released in sequence and the workpiece is removed.

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