A laser welding device for connecting the head and tail of a substrate roll in a color-coated sheet production line

Abstract

The application discloses a laser welding device for connecting the head and tail of a base material roll of a color-coated sheet production line, and the device comprises a gantry type frame, a centering fixing clamp, a high-precision visual detection system, a laser cutting and welding assembly, a cooling system, a servo control system and a circulation control system. The device controls the gap between the head and tail of the base material within 0.05 mm through independent air path linkage control and constant temperature cooling design, and cooperates with micron-level visual closed-loop alignment to complete the butt joint of the base material through the full-automatic processes of pretreatment cutting, accurate alignment and laser self-fusion welding. The device can be adapted to full-specification color-coated base materials, the welds are flat and free of protrusions and defects, the device can realize continuous coating of the production line without lifting the roller, prevents leakage coating waste, has high automation degree and operation stability, and effectively improves the production yield and production efficiency.

Description

Technical Field

[0001] This invention belongs to the technical field of color-coated steel coil production equipment, specifically relating to a laser welding device for connecting the head and tail of a color-coated steel coil production line. It is suitable for automated butt welding of the head and tail of color-coated steel coils of different thicknesses and widths, and can be widely used in continuous production lines for color-coated steel coils of galvanized steel, aluminized zinc steel, aluminum steel, stainless steel, and cold-rolled steel. Background Technology

[0002] Color-coated steel coils are composite decorative and structural panels made from various metal sheets as substrates, through surface pretreatment, continuous coating, baking and curing, and cooling and shaping. With advantages such as corrosion resistance, beautiful appearance, and good formability, they are widely used in building roofs, wall cladding, appliance casings, and decorative components. At the entrance section of a continuous color-coated steel coil production line, the industry generally adopts a double-rolling, rotating feeding mode. When the previous roll of substrate is about to finish, the beginning of the next roll must be reliably connected to the end of the previous roll to ensure continuous operation of the production line without stopping, avoiding capacity loss and production cycle interruptions caused by roll changing downtime.

[0003] Existing color coating production lines can accommodate a wide range of substrate specifications, with substrate thicknesses ranging from 0.075mm to 1.5mm and substrate widths from 650mm to 1800mm. Among them, the ultra-thin 0.075mm substrate has an extremely thin wall thickness, making it extremely sensitive to welding heat input, welding speed, and butt joint gap. Conventional welding methods are prone to defects such as burn-through, pinholes, weld protrusions, and wavy deformation. On the other hand, the 1800mm wide substrate places extremely high demands on the uniformity of clamping, equipment stroke, alignment accuracy, and welding stability of the welding equipment. Ordinary butt joint equipment is unable to achieve uniform and deviation-free butt joint welding of the entire plate.

[0004] Currently, most color-coated substrates in the industry use physical connection methods such as mechanical riveting and stamping to connect the ends. These connection methods have many insurmountable defects: First, the mechanical connection position has obvious protruding structures. When the coating roller passes through the protruding position at high speed, it is easy to be squeezed, bumped, and worn, causing damage to the coating roller and deformation of the roller surface. In order to protect the equipment, the coating roller must be temporarily raised during production, resulting in the corresponding board section being unable to be coated, forming a large area of ​​uncoated waste products, which need to be manually cut and scrapped, resulting in large raw material loss and low yield. Second, the bonding strength of mechanical riveting is limited. Under the high tension and continuous traction conditions of the production line, the riveting position is prone to cracking, slippage, and strip breakage, causing emergency shutdown of the production line, which seriously affects the continuity and efficiency of production. Third, traditional connection methods have poor adaptability and cannot meet the production needs of ultra-thin plates and wide thick plates, resulting in a high rate of product scrap and high overall production costs.

[0005] While a few welding-type butt welding devices exist in the current technology, they generally suffer from low automation, poor alignment accuracy, unstable weld quality, inability to achieve micron-level gap control, excessive weld height after welding, and numerous defects. They still cannot meet the production requirements of color coating production lines, such as roller-free operation, continuous coating, and zero missed coating. Therefore, developing a laser welding device that is compatible with all substrate sizes, has high butt welding accuracy, produces smooth, bulge-free welds, is highly automated, and can ensure continuous, uninterrupted production is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] This invention aims to solve the problems of numerous weld defects, easy equipment damage, large amount of uncoated scrap, frequent downtime due to tape breakage, poor specification adaptability, and low production efficiency in existing color-coated coil substrate connection processes. It provides a laser welding device for connecting the beginning and end of color-coated coil substrates in a color-coated coil production line. This invention integrates automated cutting, high-precision alignment, and laser self-fusion welding, enabling smooth and defect-free butt welding of color-coated substrates of all specifications. After welding, the weld seam has no excess height, no holes, and no protrusions. The coating roller can pass directly and smoothly without the need for roller lifting, completely eliminating uncoated scrap, significantly improving the production line yield and continuous operation capability, and reducing production losses and maintenance costs.

[0007] To achieve the above objectives, the present invention employs the following technical means: A laser welding device for connecting the head and tail of a color-coated steel coil production line includes: a gantry frame; an inlet centering fixture and an outlet centering fixture, both mounted on the gantry frame, for clamping and fixing the tail and head of the steel coil respectively; a high-precision vision inspection system for acquiring images of the steel coil head-tail docking area and providing alignment data; a cutting laser generator and a welding laser generator; a laser cutting head connected to the cutting laser generator for pre-processing cutting of the steel coil tail and head; a laser welding head connected to the welding laser generator for laser welding of the steel coil head-tail docking point; a waste and slag receiving hopper located below the laser cutting station for collecting cutting waste and slag; and a welding support platform. At the welding station, there is a support for the steel coil head and tail docking area; a cylinder drive assembly for driving the various fixtures and motion mechanisms; a tooling cooling system for cooling the laser cutting head, laser welding head, and welding support platform; a servo control system for driving and controlling the position and speed of each motion axis; and a laser welding machine work cycle control system, which is electrically connected to the inlet centering fixture, outlet centering fixture, high-precision vision inspection system, cutting laser generator, welding laser generator, cylinder drive assembly, tooling cooling system, and servo control system, respectively, to control the entire machine to complete the automated operation of initialization, work preparation, steel coil tail pre-treatment cutting, steel coil head pre-treatment cutting, and precise centering laser welding of the steel coil head and tail in a preset cycle.

[0008] Preferably, both the inlet centering fixture and the outlet centering fixture adopt a cylinder or servo drive adjustment structure, which can adaptively adjust the clamping gap and clamping force according to the thickness and width of the substrate. The servo control system can preset clamping parameters and welding parameters corresponding to different specifications, and adapt to substrates of all specifications with a thickness of 0.075mm to 1.5mm and a width of 650mm to 1800mm.

[0009] Preferably, the high-precision visual inspection system has micron-level focusing detection and adaptive alignment correction functions, which can control the gap between the head and tail of the steel coil within 0.05mm.

[0010] Preferably, the laser cutting head is equipped with an independent cutting gas path solenoid valve, and the laser welding head is equipped with an independent welding gas path solenoid valve; the cutting gas path and the welding gas path are independent of each other, and the solenoid valves are linked to the start and stop actions of the corresponding lasers to achieve linkage control.

[0011] Preferably, the tooling cooling system provides constant temperature cooling to the laser cutting head, laser welding head, and welding support platform in real time.

[0012] Preferably, the laser welding machine working cycle control system includes a PLC controller, a human-machine interface and an industrial communication module. The PLC controller has a built-in sequential control program for sequentially executing the control logic of initialization, work preparation, pre-processing and cutting of the steel coil tail, pre-processing and cutting of the steel coil head, and precise alignment of the steel coil head and tail for laser welding.

[0013] Preferably, the laser welding machine work cycle control system is configured to control the entire machine to perform the following work cycle: S1. Initialization: After the machine is powered on, the reset procedure is executed. The laser cutting head and laser welding head are moved to the safe avoidance position. The laser cutting head is dispatched to the cutting station, the welding support table is lowered and positioned, the cutting waste and slag receiving hopper is moved to the receiving station, the inlet centering fixing clamp and the outlet centering fixing clamp are fully opened and reset, and the clamping gap is calibrated to the initial standard spacing. S2. Operation preparation: The high-precision vision inspection system is globally zeroed and calibrated. The vision inspection lens is moved to the preset focus position and the focus calibration is completed. S3. Steel coil tail pretreatment and cutting: The outlet centering and fixing clamp closes and holds the steel coil tail; the cutting gas line nitrogen valve is opened, the laser cutting head is locked and calibrated at a fixed point, and the laser cutting head is driven to precisely cut the tail end; after cutting, the cutting laser and the cutting gas line nitrogen valve are closed. S4. Steel coil head pretreatment and cutting: The inlet centering and fixing clamp closes and clamps the steel coil head; the cutting gas line nitrogen valve is opened, the laser cutting head is locked and calibrated at a fixed point, and the laser cutting head is driven to precisely cut the end of the head; after cutting, the cutting laser and the cutting gas line nitrogen valve are turned off. S5. Precise Alignment and Laser Welding of Steel Coil Head and Tail: The steel coil head and tail are driven to the visual inspection focus position. The high-precision visual inspection system collects the butt joint gap data in real time and feeds it back to the servo control system in a closed loop. The system adaptively fine-tunes the plate position to control the head and tail butt joint gap within 0.05mm. After the alignment is qualified, the laser welding head is driven to the welding station, the welding shielding gas is turned on and the welding point calibration is completed. The laser welding head is driven to move at a constant speed to complete the continuous laser self-fusion welding of the steel coil head and tail. After the welding is completed, the welding laser and welding shielding gas are turned off, the inlet and outlet alignment fixing clamps are opened, the welded plate is released, and the equipment is reset to the standby state.

[0014] The present invention has the following beneficial effects: 1. High alignment accuracy and excellent weld quality. This invention employs high-precision visual closed-loop alignment technology, controlling the head-to-tail gap within 0.05mm. Combined with laser self-fusion welding process, the weld is smooth, without excess height, holes, or protrusions after welding, completely solving the problems of uneven welds and frequent defects in traditional processes.

[0015] 2. Achieve continuous coating without lifting the roller, resulting in zero missed coating and waste. The welded joint of this invention is flat and smooth, allowing the coating roller to pass directly and smoothly through the weld without lifting the roller. This completely eliminates the problem of missed coating on the board caused by lifting the roller, and eliminates the need to cut scrapped boards, significantly improving the yield and reducing raw material waste.

[0016] 3. High degree of automation and strong production continuity. The whole machine adopts fully automatic cycle control, and the entire process from mechanism reset, plate pretreatment, cutting, alignment and welding is completed automatically; the cutting gas circuit and the welding gas circuit start and stop independently at different times, avoiding long-term ineffective purging of protective gas; effectively avoiding human operation error, reducing tape breakage and shutdown failures, and significantly improving the stability and production efficiency of the production line.

[0017] 4. Wide range of specifications and strong versatility. The equipment can adaptively adjust the clamping gap, clamping force and welding parameters. Through the preset program of the servo control system, it can adapt to the production of color-coated substrates of all specifications, from ultra-thin plates to conventional thick plates, and from narrow plates to wide plates, making it suitable for a wide range of scenarios.

[0018] 5. The equipment boasts high stability and a long service life. Equipped with a dedicated tooling cooling system, it continuously cools the laser cutting head, laser welding head, and welding support table, preventing high temperatures from affecting equipment accuracy and lifespan; the two independent air circuits are linked for control, resulting in a low equipment failure rate. Attached Figure Description

[0019] Figure 1 is a schematic diagram of the overall device structure of the present invention; Figure 2 is a flowchart of the fully automatic working cycle control process of the laser welding machine of the present invention; Figure 3 is a schematic diagram of the visually precise alignment structure of the substrate roll head and roll tail of the present invention.

[0020] Explanation of markings in the diagram: 1—Gantry frame; 2—Inlet centering fixture; 3—Outlet centering fixture; 4—High-precision vision inspection system; 5—Cutting laser generator; 6—Welding laser generator; 7—Laser cutting head; 8—Laser welding head; 9—Cutting waste and slag receiving hopper; 10—Welding support table; 11—Cylinder drive assembly; 12—Tooling cooling system; 13—Servo control system; 14—Laser welding machine working cycle control system. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] like Figure 1-3 As shown, this invention discloses a laser welding equipment and welding method for connecting the head and tail of a substrate in a color-coated steel sheet production line. The laser welding machine working cycle control system 14 coordinates the coordinated operation of various mechanical mechanisms, optical components, detection components and air circuit system.

[0023] A laser welding device for connecting the head and tail of a color-coated steel coil production line includes: a gantry frame 1; an inlet centering clamp 2 and an outlet centering clamp 3, both mounted on the gantry frame 1, for clamping and fixing the tail and head of the steel coil respectively; a high-precision vision inspection system 4 for acquiring images of the steel coil head and tail docking area and feeding back alignment data; a cutting laser generator 5 and a welding laser generator 6; a laser cutting head 7 connected to the cutting laser generator 5 for pre-processing and cutting the steel coil tail and head; a laser welding head 8 connected to the welding laser generator 6 for laser welding the steel coil head and tail docking point; a waste and slag receiving hopper 9 located below the laser cutting station for collecting cutting waste and slag; and a welding support platform 10 located at the welding station for... The system includes: a support for the steel coil head and tail docking area; a cylinder drive assembly 11 for driving the various fixtures and motion mechanisms; a tooling cooling system 12 for cooling the laser cutting head 7, laser welding head 8, and welding support table 10; a servo control system 13 for driving and controlling the position and speed of each motion axis; and a laser welding machine work cycle control system 14, which is electrically connected to the inlet centering fixture 2, the outlet centering fixture 3, the high-precision vision inspection system 4, the cutting laser generator 5, the welding laser generator 6, the cylinder drive assembly 11, the tooling cooling system 12, and the servo control system 13, respectively, to control the entire machine to complete the automated operation of initialization, work preparation, steel coil tail pre-treatment cutting, steel coil head pre-treatment cutting, and precise centering laser welding of the steel coil head and tail in a preset cycle.

[0024] Both the inlet centering fixture 2 and the outlet centering fixture 3 adopt a cylinder or servo drive adjustment structure, which can adaptively adjust the clamping gap and clamping force according to the thickness and width of the substrate. The servo control system 13 presets clamping parameters and welding parameters corresponding to different specifications, which can be adapted to substrates of all specifications with a thickness of 0.075mm to 1.5mm and a width of 650mm to 1800mm.

[0025] The advantages of the above settings are: the clamping gap and clamping force can be automatically matched for color-coated substrates of different thicknesses and widths; ultra-thin plates will not be indented or wrinkled due to excessive clamping force, and thick and wide plates will not slip due to insufficient clamping force; production specifications can be quickly switched through system preset parameters, without the need for repeated manual adjustment of mechanical limits on site, the plate change and debugging time is short, and the whole machine has strong substrate versatility.

[0026] The high-precision vision inspection system 4 has micron-level focusing detection and adaptive alignment correction functions, which can control the gap between the head and tail of the steel coil within 0.05mm.

[0027] The advantages of the above settings are: to achieve closed-loop adaptive correction of the gap between the plates, reducing the alignment error caused by manual alignment; the extremely small gap between the plates is conducive to laser self-fusion welding and forming, reducing the probability of welding defects such as burn-through, lack of fusion, and pinholes; and to ensure that the weld is flat overall, with no obvious protrusion after welding, meeting the process requirements of continuous plate passing without lifting rollers in the color coating production line.

[0028] The laser cutting head 7 is equipped with an independent cutting gas path solenoid valve, and the laser welding head 8 is equipped with an independent welding gas path solenoid valve; the cutting gas path and the welding gas path are independent of each other, and the solenoid valves are linked to the start and stop actions of the corresponding lasers to achieve linkage control.

[0029] The advantages of the above setup are: the cutting and welding protective gas paths do not interfere with each other and are opened and closed synchronously with the laser output; continuous gas supply is not required throughout the process, reducing the consumption of protective gas and saving gas costs; at the same time, it avoids mutual disturbance of gas pressure between different workstations, ensuring stable cutting and slag removal effects and welding pool protection effects, and preventing oxidation and discoloration of the weld.

[0030] The tooling cooling system 12 provides real-time constant temperature cooling for the laser cutting head 7, laser welding head 8, and welding support table 10.

[0031] The advantages of the above settings are: continuously removing the large amount of heat generated by laser operation, suppressing temperature rise and drift of the laser head optical components, and maintaining stable laser output power; avoiding thermal deformation of the welding support table due to long-term heating, ensuring the accuracy of the plate support plane; improving the stability of the whole machine during continuous long-term operation, and extending the service life of optical components and tooling table.

[0032] The laser welding machine working cycle control system 14 includes a PLC controller, a human-machine interface and an industrial communication module. The PLC controller has a built-in sequential control program, which is used to sequentially execute the control logic of initialization, work preparation, steel coil tail pre-treatment cutting, steel coil head pre-treatment cutting and precise alignment of steel coil head and tail for laser welding.

[0033] The advantages of the above setup are: the entire head and tail welding process can be programmed and automatically executed sequentially, reducing manual step-by-step operation intervention; operators can complete parameter setting and status monitoring only through the human-machine interface; the industrial communication module facilitates signal interaction with the upstream color coating production line main control system, can be integrated into the automated interlocking control of the entire production line, and is conducive to continuous unmanned roll changing operations on the production line.

[0034] A laser welding method for connecting the beginning and end of a color-coated steel coil in a production line, using the aforementioned laser welding equipment, includes the following steps: Step 1: Laser welding machine initialization After the equipment is powered on, the initialization and reset procedure is executed first. The control system drives the laser cutting head 7 and the laser welding head 8 to move synchronously to a safe avoidance position, opens the nitrogen valve, and precisely schedules the laser cutting head 7 to the preset cutting position; controls the welding support platform 10 to descend and position, drives the cutting waste and slag receiving hopper 9 to move to the receiving position, ensuring that all waste and slag generated during cutting can be collected to avoid contaminating the equipment and the sheet metal; controls the inlet clamp 2 and the outlet clamp 3 to fully open, the inlet clamp 2 to complete the lateral reset, and the outlet clamp 3 to move to the rear initial position. At the same time, the clamping gap of the two sets of clamps is calibrated to the initial standard distance. All moving mechanisms and tooling structures of the whole machine are reset to zero, completing the mechanism initialization preparation before operation.

[0035] Step 2: Preparation for Laser Welding Machine Operation After initialization, the equipment automatically enters standby mode. The system controls the vision inspection system 4 to complete global zeroing calibration, the laser welding head 8 to maintain a safe position, the nitrogen valve to be closed, the laser cutting head 7 to maintain the cutting position, and the support table 10, receiving hopper 9, fixture positions, and fixture gaps to maintain their initialization state. Based on this, the vision inspection lens is individually driven to precisely move to the preset focus point position, completing preprocessing work such as lens focusing and parameter calibration to ensure micron-level detection accuracy for subsequent plate alignment and weld inspection.

[0036] Step 3: Pre-treatment and cutting of the steel coil tail During normal operation of the color coating production line, when the tail of the current steel coil approaches the welding machine's workstation, the system's tail pretreatment process is initiated. First, the exit clamp 3 is closed to stably hold the steel coil tail, preventing sheet material shifting or shaking. Simultaneously, the nitrogen valve is opened, locking the laser cutting head 7 at the cutting station and completing laser positioning calibration. The laser cutting head 7 is then driven to move at a uniform speed, precisely cutting the tail end of the steel coil to remove irregular ends, burrs, and deformed sections, ensuring a flat and neat cut surface. After cutting, the laser cutting function is sequentially turned off, the positioning calibration is canceled, and the nitrogen valve is closed. The vision lens maintains its focus position, completing the tail pretreatment operation.

[0037] Step 4: Pre-treatment and cutting of steel coil ends After the production line is pulled, the lead of a spare steel coil is moved to the middle working area of ​​the welding machine, and the system starts the lead pretreatment program. The inlet clamp 2 closes to clamp the steel coil lead, completing the plate positioning and fixing; the nitrogen valve is opened to lock the laser cutting head 7 and complete the cutting point calibration; the laser cutting head 7 is driven to run, precisely cutting and trimming the lead end, removing defective sections, and ensuring the lead end face is flat, burr-free, and deformation-free. After the cutting process is completed, the laser cutting is turned off and the nitrogen valve is closed in sequence, completing the steel coil lead pretreatment and providing a flat reference surface for precise end-to-end joining.

[0038] Step 5: Precise alignment of the steel coil ends and laser welding. After the pre-treatment of the tail and head of the steel coil is completed, the high-precision butt welding process begins. The system drives the tail and head of the steel coil to the visual inspection focus position to complete the initial alignment. The high-precision visual inspection system 4 collects the butt gap data in real time and feeds it back to the servo control system 13 in a closed loop. The system adaptively fine-tunes the plate position to strictly control the head-tail butt gap within 0.05mm, achieving micron-level precision alignment. After the alignment is qualified, the laser welding head 8 is driven to move to the welding station, the welding shielding gas is turned on, and the welding point calibration is completed. The laser welding head 8 is driven to move at a constant speed, and the laser self-fusion welding process is used to complete the continuous welding operation of the head and tail of the steel coil. After the welding trajectory reaches the preset endpoint, the laser welding function is turned off and the welding shielding gas is turned off in sequence to end the welding operation. Finally, the inlet and outlet clamps are opened simultaneously to release the welded plate. After a single welding cycle is completed, the equipment automatically resets to the standby state, waiting for the next coil change welding command.

[0039] In practical applications, the equipment of this invention can adaptively match different sheet materials by pre-setting corresponding clamping parameters, cutting stroke, welding speed, laser power, and focusing parameters according to the specifications of the substrate material on the production line through the servo control system 13. The equipment's cooling system maintains a constant temperature for the laser cutting head 7, laser welding head 8, and welding support table throughout the process, avoiding equipment precision drift and component aging caused by continuous high temperatures, thus ensuring long-term stable operation. Simultaneously, the fully automated closed-loop control effectively reduces manual intervention and human error, significantly improving the automation and intelligent production level of the color coating production line.

[0040] Example 1 (Ultra-thin galvanized steel sheet, 0.3mm thick, 1250mm wide) This embodiment is used for the end-to-end joining of 0.3mm thick, 1250mm wide galvanized steel sheet color-coated substrate; the entire equipment frame adopts a gantry frame 1, and the inlet centering fixing fixture 2 and outlet centering fixing fixture 3 adopt servo-driven clamping structures; the high-precision vision inspection system 4 uses a 5μm resolution linear CCD camera with a telecentric lens; the alignment fine-tuning platform has a resolution of 0.5μm; the cutting laser generator 5 uses a 3500W pulsed fiber laser to drive the laser cutting head 7 to complete the plate end trimming; the welding laser generator 6 uses a 2500W single-mode laser. A fiber laser drives the laser welding head 8 to perform self-fusion welding; a waste and slag receiving hopper 9 is arranged below the laser cutting station; a welding support table 10 is arranged at the welding station; a cylinder drive assembly 11 assists in completing the movement of the receiving hopper; a tooling cooling system 12 uses circulating cooling water, set to a constant temperature of 22±1℃ and a flow rate of 20L / min, to continuously cool the laser cutting head 7, laser welding head 8, and welding support table 10; a servo control system 13 controls each motion axis; and a laser welding machine working cycle control system 14 executes the entire set of automatic operation logic.

[0041] Process parameters: Laser cutting nitrogen pressure 0.6MPa, cutting speed 20m / min; welding shielding gas is nitrogen, flow rate 18L / min; welding speed 11m / min, defocusing amount +0.8mm, laser power 1600W; the butt gap is controlled by a high-precision vision inspection system with 4 closed loops ≤0.05mm.

[0042] Operation process: Under the control of the laser welding machine working cycle control system 14, the equipment sequentially executes S1 initialization-S2 operation preparation-S3 tail pretreatment cutting-S4 head pretreatment cutting-S5 precise centering laser welding; after welding, the weld is flat with no excess height, no burn-through, and no wave deformation in the weld area; the color coating production line can directly and continuously pass through the plate for coating without lifting the roller, and there are no missed coating waste products.

[0043] Example 2 (medium thickness cold-rolled steel sheet, 0.8 mm thick, 1500 mm wide) This embodiment is used for the end-to-end butt welding of 0.8mm thick, 1500mm wide cold-rolled steel sheet with color coating. The main body of the equipment still adopts a gantry frame 1. The inlet centering fixing clamp 2 and the outlet centering fixing clamp 3 are automatically adjusted by the servo control system 13 according to the 1500mm width of the sheet. The high-precision vision inspection system 4 still adopts a 5μm linear CCD telecentric vision component. The cutting laser generator 5 and the laser cutting head 7 complete the end face trimming of the strip. The welding laser generator 6 and the laser welding head 8 complete the self-fusion welding. The cutting waste and slag receiving hopper 9 collects the cut-off plate edge waste. The welding support table 10 carries the butt-welded sheet. The cylinder drive assembly 11 drives the cutting waste and slag receiving hopper 9 to move forward and backward. The tooling cooling system 12 maintains the cooling water at a constant temperature of 22±1℃ to keep the laser cutting head 7, laser welding head 8, and welding support table 10 constantly cooled. The servo control system 13 is responsible for the servo fine adjustment of the sheet alignment. The laser welding machine working cycle control system 14 completes the entire cycle timing control.

[0044] Process parameters: cutting nitrogen pressure 0.6MPa, cutting speed 20m / min; welding shielding gas nitrogen flow rate 18L / min; welding speed 10m / min, defocusing amount -0.5mm, laser power 2200W; the butt gap is controlled by a high-precision vision inspection system with a closed loop of 4, ≤0.05mm.

[0045] Results: The weld has no internal pores and the surface is smooth without protrusions; after high-tension traction testing on the production line, the weld shows no cracks; the coating roller can pass directly without lifting the roller, and there are no sections with missed coating or scrap.

[0046] Example 3 (thick stainless steel plate, 1.5mm thick, 1800mm wide) This embodiment is used for the end-to-end docking of 1.5mm thick, 1800mm wide stainless steel color-coated substrates; the gantry frame 1 accommodates the 1800mm maximum plate width travel; the inlet centering fixture 2 and outlet centering fixture 3 are servo driven, and the servo control system 13 automatically adapts to the maximum width clamping range; the high-precision vision inspection system 4's camera field of view covers the entire 1800mm plate width; the cutting laser generator 5 outputs 2200W to drive the laser cutting head 7 for end face trimming; the welding laser generator 6 outputs 3300W to drive the laser welding head 8; the cutting waste and slag receiving hopper 9 receives the cutting waste from the wide plate; the welding support table 10 fully supports the 1800mm wide docking area; the cylinder drive assembly 11 drives the receiving hopper to move; the tooling cooling system 12 maintains cooling water at 22±1℃, continuously cooling the laser cutting head 7, laser welding head 8, and welding support table 10; the servo control system 13 completes the left-right fine-tuning alignment of the wide plate; and the laser welding machine work cycle control system 14 executes the fully automatic operation sequence.

[0047] Process parameters: laser cutting speed 15m / min, cutting nitrogen pressure 0.6MPa; welding shielding gas is nitrogen, flow rate 35L / min; welding speed 8m / min, defocusing amount -2mm, laser power 3300W; the butt gap is strictly controlled by a high-precision vision inspection system with 4 closed loops, ≤0.05mm.

[0048] Work results: After the ends of the wide stainless steel plates are joined, the weld seam is fully fused and there are no defects of incomplete fusion; the surface of the entire 1800mm weld seam is flat and without excess height; the tensile strength of the weld seam reaches the level of the base material under high tension traction conditions; the color coating production line realizes continuous coating without lifting the roller and without waste cutting.

[0049] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0050] The examples provided in this invention are not intended to limit the implementation. Those skilled in the art will recognize that various variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations, and any obvious variations or modifications derived therefrom are still within the scope of this invention.

Claims

1. A laser welding device for connecting the head and tail of a color-coated steel coil production line substrate, characterized in that, include: A gantry frame (1); an inlet centering fixture (2) and an outlet centering fixture (3) are both mounted on the gantry frame (1) and are used to clamp and fix the tail and head of the steel coil respectively; a high-precision vision inspection system (4) is used to collect images of the steel coil head and tail docking area and provide feedback on alignment data; a cutting laser generator (5) and a welding laser generator (6); a laser cutting head (7) is connected to the cutting laser generator (5) and is used to pre-process and cut the tail and head of the steel coil; a laser welding head (8) is connected to the welding laser generator (6) and is used to perform laser welding at the head and tail docking point of the steel coil; a cutting waste and slag receiving hopper (9) is located below the laser cutting station and is used to collect cutting waste and slag; a welding support platform (10) is located at the welding station and is used to support the head and tail docking area of ​​the steel coil; gas The cylinder drive assembly (11) is used to drive the various fixtures and motion mechanisms; the tooling cooling system (12) is used to cool the laser cutting head (7), the laser welding head (8) and the welding support table (10); the servo control system (13) is used to drive and control the position and speed of each motion axis; and the laser welding machine working cycle control system (14) is electrically connected to the inlet centering fixed fixture (2), the outlet centering fixed fixture (3), the high-precision vision inspection system (4), the cutting laser generator (5), the welding laser generator (6), the cylinder drive assembly (11), the tooling cooling system (12) and the servo control system (13), respectively, and is used to control the whole machine to complete the automated operation of initialization, work preparation, steel coil tail pretreatment cutting, steel coil head pretreatment cutting and steel coil head and tail precise centering laser welding in a preset cycle.

2. The laser welding equipment for connecting the head and tail of the substrate in a color-coated steel coil production line according to claim 1, characterized in that, The inlet centering fixture (2) and the outlet centering fixture (3) both adopt a cylinder or servo drive adjustment structure, which can adaptively adjust the clamping gap and clamping force according to the thickness and width of the substrate. The servo control system (13) presets the clamping parameters and welding parameters corresponding to different specifications, and is suitable for substrates with a thickness of 0.075mm to 1.5mm and a width of 650mm to 1800mm.

3. The laser welding equipment for connecting the head and tail of the substrate in a color-coated steel coil production line according to claim 1, characterized in that, The high-precision visual inspection system (4) has micron-level focusing detection and adaptive alignment correction functions, which can control the gap between the head and tail of the steel coil within 0.05mm.

4. The laser welding equipment for connecting the head and tail of the substrate in a color-coated steel coil production line according to claim 1, characterized in that, The laser cutting head (7) is equipped with an independent cutting gas path solenoid valve, and the laser welding head (8) is equipped with an independent welding gas path solenoid valve; the cutting gas path and the welding gas path are independent of each other, and the solenoid valves are linked to the start and stop actions of the corresponding lasers to achieve solenoid valve linkage control.

5. The laser welding equipment for connecting the head and tail of the substrate in a color-coated steel coil production line according to claim 1, characterized in that, The tooling cooling system (12) provides constant temperature cooling for the laser cutting head (7), laser welding head (8), and welding support table (10) in real time.

6. The laser welding equipment for connecting the head and tail of the substrate in a color-coated steel coil production line according to claim 1, characterized in that, The laser welding machine working cycle control system (14) includes a PLC controller, a human-machine interface and an industrial communication module. The PLC controller has a built-in sequential control program, which is used to sequentially execute the control logic of initialization, work preparation, steel coil tail pretreatment cutting, steel coil head pretreatment cutting and steel coil head and tail precise centering laser welding.

7. The laser welding equipment for connecting the head and tail of the substrate in a color-coated steel coil production line according to claim 1, characterized in that, The laser welding machine work cycle control system (14) is configured to control the entire machine to perform the following work cycle: S1. Initialization: After the machine is powered on, the reset procedure is executed. The laser cutting head (7) and the laser welding head (8) are moved to the safe avoidance position. The laser cutting head (7) is dispatched to the cutting station, the welding support table (10) is lowered into place, the cutting waste and slag receiving hopper (9) is moved to the receiving station, the inlet centering fixing clamp (2) and the outlet centering fixing clamp (3) are fully opened and reset, and the clamping gap is calibrated to the initial standard spacing. S2. Operation preparation: High-precision visual inspection system (4) global zero calibration, visual inspection lens moves to the preset focus position and completes focus calibration; S3, steel coil tail pretreatment and cutting: the outlet centering and fixing clamp (3) closes and clamps the steel coil tail; the cutting gas path nitrogen valve is opened, the laser cutting head (7) is locked and fixed point is calibrated, and the laser cutting head (7) is driven to accurately cut the tail end; After cutting is completed, turn off the cutting laser and the nitrogen valve in the cutting gas path; S4. Steel coil head pretreatment and cutting: The inlet centering and fixing clamp (2) closes and clamps the steel coil head; the cutting gas path nitrogen valve is opened, the laser cutting head (7) is locked and calibrated at a fixed point, and the laser cutting head (7) is driven to accurately cut the end of the head; after the cutting is completed, the cutting laser and the cutting gas path nitrogen valve are closed. S5. Precise alignment of steel coil head and tail and laser welding: Drive the tail and head of the steel coil to the visual inspection focus position. The high-precision visual inspection system (4) collects the gap data of the joint in real time and feeds it back to the servo control system (13) in a closed loop. Adaptively fine-tune the position of the plate so that the gap between the head and tail is controlled within 0.05mm. After the alignment is qualified, drive the laser welding head (8) to move to the welding station, turn on the welding shielding gas and complete the welding point calibration. Drive the laser welding head (8) to walk at a constant speed to complete the continuous laser self-fusion welding of the head and tail of the steel coil. After the welding is completed, turn off the welding laser and the welding shielding gas, open the inlet centering fixing clamp (2) and the outlet centering fixing clamp (3), release the welded plate, and reset the equipment to the standby state.

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