Laser filler wire welding seam forming control method and system

Abstract

The invention relates to the field of laser welding, in particular to a laser filler wire welding seam forming control method and system. A welding wire is unfolded from a welding wire reel and enters a welding wire control system; the welding wire control system straightens the welding wire and controls the wire feeding speed; a welding wire enters a welding pool through a wire feeding pipeline; a welding seam gap signal acquisition module is arranged in front of the molten pool in the welding wire direction and used for acquiring welding seam gap signals in real time; and the collected welding seam gap signal is fed back to a welding wire control system, and the wire feeding speed is adjusted in real time according to the welding seam gap, the thickness of a welding plate, the welding speed and the diameter of a welding wire. The method has the advantages that the feeding speed of the welding wire is dynamically adjusted based on the welding seam gap signals collected in real time, the filling amount of the welding wire adapts to welding seam gap changes, wire feeding is accelerated when the welding seam gap is large, wire feeding is slowed down when the welding seam gap is small, and therefore the welding seam plumpness consistency is remarkably improved; and the necking or sinking defect that the initial position of the weld joint is full and the end position is insufficient in filling is avoided.

Description

Technical Field

[0001] This invention relates to the field of laser welding, and in particular to a method and system for controlling the formation of laser filler wire welds. Background Technology

[0002] Laser welding technology is widely used in industrial manufacturing due to its significant advantages such as concentrated energy, high welding precision, small heat-affected zone, and high weld strength. In laser welding without filler wire, the weld metal is formed entirely by the melting and cooling of the base material. However, in actual welding, due to the highly concentrated laser energy, the base metal is prone to vaporization and melting. If there is uneven processing on the weld side of the steel plate, it will lead to inconsistent weld gap sizes, resulting in an uneven necking morphology on the weld surface. In addition, during the welding process, it is common to see a small weld gap at the beginning, which gradually widens as welding progresses, leading to uneven overall weld formation—a fuller gap at the beginning and insufficient filling at the end.

[0003] To address the aforementioned issues, laser wire feed welding has become a commonly used technical solution. This method involves uniformly adding welding wire into the weld to replenish the weld metal and improve weld fullness. While this method works well when the weld gap is uniform, it is less effective when welding workpieces with cumulative errors, such as door rings. In such cases, traditional uniform wire feeding methods are no longer sufficient to meet the demands of high-quality, high-consistency industrial production.

[0004] In the prior art, patent publication number CN105499814A discloses an invention patent for "Wire feeding method for laser filler wire welding," which improves weld formation and enhances process adaptability and welding stability by adopting integrated push-pull wire control and precise synchronization with the laser head movement. Patent publication number CN106670649A discloses an invention patent for "Laser filler wire welding method," which effectively solves the welding difficulties of thin aluminum alloy plates by optimizing welding process parameters, improving weld formation and reducing the requirements for assembly precision.

[0005] Although the aforementioned patents have some effect on improving the weld formation of laser welding, none of them have proposed specific control measures and solutions for the uneven weld gap. Therefore, when faced with gap fluctuations that are common in actual production, there are still technical defects such as inconsistent weld formation and unstable quality. Summary of the Invention

[0006] The purpose of this invention is to provide a laser wire filler welding weld formation control method and system, which dynamically adjusts the wire feeding speed to achieve adaptive matching between the wire feeding amount and the weld gap, effectively solving problems such as inconsistent weld formation, necking or insufficient filling caused by uneven weld gap, improving weld fullness and uniformity, enhancing the adaptability of the welding process to workpiece assembly errors, and reducing dependence on the accuracy of the previous processing.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A method for controlling the formation of laser-assisted filler wire welding seams includes: S1. The welding wire is unwound from the welding wire spool and enters the welding wire control system; S2. The welding wire control system straightens the welding wire and controls the wire feeding speed; S3. The welding wire enters the welding pool through the wire feeding pipe; S4. A weld gap signal acquisition module is set in front of the molten pool in the direction of the welding wire to acquire the weld gap signal in real time. S5. The acquired weld gap signal is fed back to the welding wire control system and the laser power control system. Based on the weld gap, welding plate thickness, welding speed, and welding wire diameter, the wire feed speed and laser output power are adjusted in real time, using the following formula: The formula for calculating the wire feeding speed is: ①; The laser output power is given by the formula: ② in: Indicates the wire feeding speed, in mm / s; This indicates the welding speed, expressed in mm / s. This indicates the thickness of the welded plate, in mm. This indicates the weld gap, in mm. This indicates the diameter of the welding wire, in mm.

[0008] P represents laser output power, measured in kW; A, B, and C represent constants.

[0009] The thickness of the welding plate ranges from 0.6 to 3.0 mm.

[0010] The diameter of the welding wire is in the range of 0.8~1.2mm.

[0011] The weld gap ranges from 0.1 to 0.7 mm.

[0012] This includes a welding wire control system, which is a welding wire straightening mechanism.

[0013] The welding wire straightening mechanism includes a wire quantity detection unit and a wire straightening unit. The wire quantity detection unit detects the wire feeding quantity and controls the wire feeding speed; the wire straightening unit straightens the welding wire.

[0014] It also includes a wire spool, wire feeding pipe, laser head, and weld gap signal acquisition module; The wire spool is connected to the input end of the wire control system for supplying welding wire; The output end of the welding wire control system is connected to the wire feeding pipe for conveying and straightening the welding wire; The weld gap signal acquisition module is set on the welding path in front of the wire feeding pipe. The signal output end of the weld gap signal acquisition module is connected to the control input end of the welding wire control system to acquire and provide weld gap signals in real time. The straightened welding wire enters the welding pool through the wire feeding pipe. Under the action of the laser head, it melts together with the steel plate base material to be welded to form a weld.

[0015] The end of the wire feeding pipe is equipped with a welding nozzle, which is used to guide the welding wire and feed it into the welding pool.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. By acquiring the weld gap signal in real time and dynamically adjusting the wire feeding speed based on the signal, the wire filling amount can adapt to the changes in weld gap. When the weld gap is large, the wire feeding is accelerated, and when the weld gap is small, the wire feeding is slowed down, thereby significantly improving the uniformity of weld fullness and avoiding necking or depression defects where the weld is full at the beginning and insufficient at the end. This effectively solves the forming problem caused by uneven weld gap. 2. By adopting a formulaic and parameterized wire feeding speed control strategy, combined with welding speed, plate thickness, wire diameter and real-time weld gap, more accurate calculation and dynamic adjustment of wire feeding amount can be achieved. It is especially suitable for laser filler wire welding of common materials such as cold-rolled steel plates. Stable and uniform weld formation can be achieved within the process window of plate thickness 0.6~3.0mm, wire diameter 0.8~1.2mm and plate gap width 0.1~0.7mm. 3. Closed-loop control enables more precise matching of welding wire consumption, avoiding weld defects caused by excessive wire feeding or insufficient wire feeding, thus achieving dynamic adjustment of welding parameters, improving the product qualification rate of welded plates, and reducing product scrap rate. 4. In the welding of workpieces such as door rings, where uneven weld gaps are easily caused by cumulative errors, the present invention can still maintain good weld formation quality, reduce the stringent requirements on the precision of early processing and assembly, and expand the applicable scenarios of laser filler wire welding technology. 5. The weld gap signal acquisition module is located in front of the molten pool, enabling real-time signal detection and feedback; the welding wire control system works in sync with the laser head, supporting precise control of wire feeding, stopping, and drawing, further enhancing the consistency and controllability of the welding process. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the laser filler wire welding weld formation control system.

[0018] In the diagram: 1. Welding wire spool; 2. Welding wire control system; 3. Wire feeding pipe; 4. Laser head; 5. Weld gap signal acquisition module. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0020] The following embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments. Unless otherwise specified, the methods used in the following embodiments are conventional methods.

[0021] Example See Figure 1 A laser filler wire welding weld formation control system includes a wire spool 1, a wire feeding pipe 3, a laser head 4, a weld gap signal acquisition module 5, and a wire control system 2. The wire control system 2 is a wire straightening mechanism, which includes a wire quantity detection unit and a wire straightening unit. The wire quantity detection unit is used to detect the wire feeding quantity and control the wire feeding speed. The wire straightening unit is used to straighten the welding wire. The wire spool 1 is connected to the input end of the wire control system 2 for supplying the welding wire; the output end of the wire control system 2 is connected to the wire feeding pipe 3 for conveying and straightening the welding wire; the weld gap signal acquisition module 5 is set on the welding path in front of the wire feeding pipe 3, and the signal output end of the weld gap signal acquisition module 5 is connected to the control input end of the wire control system 2 and the laser head 4 for real-time acquisition and providing weld gap signals to the wire control system 2 and the laser head 4; the straightened welding wire enters the welding pool through the wire feeding pipe 3, and under the action of the laser head 4, it melts together with the steel plate base material to be welded to form a weld; the end of the wire feeding pipe 3 is equipped with a welding nozzle for guiding the welding wire and feeding it into the welding pool.

[0022] A method for controlling the formation of laser-assisted filler wire welding seams includes: S1. The welding wire is unwound from the welding wire spool 1 and enters the welding wire control system 2; S2, Welding wire control system 2 straightens the welding wire and controls the wire feeding speed; S3. The welding wire enters the welding pool through the wire feeding pipe 3; S4. A weld gap signal acquisition module 5 is set in front of the molten pool in the direction of the welding wire to acquire the weld gap signal in real time. S5. The collected weld gap signal is fed back to the welding wire control system 2 and the laser head 4. Based on the weld gap, welding plate thickness, welding speed, and welding wire diameter, the wire feeding speed and laser power are adjusted in real time. The calculation formula for the wire feeding speed is ①, and the calculation formula for the laser power is ②. ①; ② in: Indicates the wire feeding speed, in mm / s; This indicates the welding speed, expressed in mm / s. P represents laser output power, measured in kW; A, B, and C represent constants.

[0023] The value represents the thickness of the welded plate in mm, ranging from 0.6 to 3.0 mm. The wire speed control is based on the design of the wire speed control for laser filler wire welding of cold-rolled steel plates. If the thickness of the welded plate is too low or too high, the welding loss of the steel plate will be different, and the wire speed needs to be redesigned and optimized. The weld gap, expressed in mm, is the width of the weld seam. The value ranges from 0.1 to 0.7 mm. A larger weld gap requires a higher filler wire speed, while a smaller gap requires a lower filler wire speed. When t is less than 0.1 mm, the weld gap is negligible, and the filler wire compensates for weld burn-off and increases weld fullness. When t is greater than 0.7 mm, the weld gap is too large, making it prone to weld leaks, which cannot be compensated for even with filler wire. This indicates the diameter of the welding wire, in mm, with a range of 0.8~1.2mm. Because the laser welding spot diameter is small, the larger the welding wire diameter, the less the spot can cover the welding wire. During the welding process, the welding wire is very likely to not melt completely. If the welding wire diameter is too small, the processing difficulty is high and the straightening of the welding wire is difficult. The welding wire control system of the present invention can be coordinated with the laser head movement to achieve synchronous control with laser light output and stop, and realize precise wire feeding, wire stopping, wire drawing and other actions.

[0024] Table 1 shows the specific parameters of the embodiments and comparative examples of the present invention. The welding wire is unwound from the wire spool 1 and enters the welding wire control system 2. The welding wire control system 2 receives the weld gap signal transmitted by the weld gap signal acquisition module 5 and calculates and adjusts the wire feed speed in real time based on this signal. The adjusted welding wire enters the welding pool through the wire feeding pipe and welding nozzle 3, and under the action of the laser head 4, melts together with the metal to be welded to form a weld. Because the weld gap changes in real time, the wire feed speed is also adaptively adjusted: the wire feed speed is fast when the weld gap is large, and slow when the weld gap is small. This control method effectively overcomes the problems of inconsistent weld fullness and uneven formation caused by uneven weld gaps, achieving uniform welding of welds with different gaps.

[0025] Table 1 shows the parameters for the examples and comparative examples.

[0026] This invention acquires weld gap signals in real time and dynamically adjusts the wire feed speed based on these signals. This allows the wire filler amount to adapt to changes in the weld gap, accelerating wire feed when the gap is large and slowing it down when the gap is small. This significantly improves the uniformity of weld fullness and avoids necking or depression defects where the weld starts full but ends insufficiently, effectively solving the forming problem caused by uneven weld gaps. A formulaic and parameterized wire feed speed control strategy, combined with welding speed, plate thickness, wire diameter, and real-time weld gap, enables more precise calculation and dynamic adjustment of the wire feed amount. This is particularly suitable for laser filler welding of common materials such as cold-rolled steel plates, within a process window of 0.6~3.0mm plate thickness, 0.8~1.2mm wire diameter, and 0.1~0.7mm weld width. Within the weld pool, stable and uniform weld formation can be achieved. Closed-loop control enables more precise matching of wire feed, avoiding weld height discrepancies caused by excessive wire feeding or dimensional inaccuracies due to insufficient wire feeding. Dynamic adjustment of welding parameters improves the product qualification rate of welded plates and reduces scrap rate. Even in welding workpieces such as door rings where uneven weld gaps are easily caused by cumulative errors, this invention maintains good weld formation quality, reducing stringent requirements for pre-processing and assembly precision, and expanding the application scenarios of laser filler wire welding technology. The weld gap signal acquisition module is located in front of the molten pool, enabling real-time signal detection and feedback. The wire control system works synchronously with the laser head, supporting precise control of wire feeding, stopping, and retraction, further enhancing the consistency and controllability of the welding process.

Claims

1. A method for controlling the formation of laser-assisted filler wire welding seams, characterized in that, include: S1. The welding wire is unwound from the welding wire spool and enters the welding wire control system; S2. The welding wire control system straightens the welding wire and controls the wire feeding speed; S3. The welding wire enters the welding pool through the wire feeding pipe; S4. A weld gap signal acquisition module is set in front of the molten pool in the direction of the welding wire to acquire the weld gap signal in real time. S5. The acquired weld gap signal is fed back to the welding wire control system and the laser power control system. Based on the weld gap, welding plate thickness, welding speed, and welding wire diameter, the wire feed speed and laser output power are adjusted in real time, using the following formula: The formula for calculating the wire feeding speed is: ①； The laser output power is given by the formula: ② in: Indicates the wire feeding speed, in mm / s; This indicates the welding speed, expressed in mm / s. This indicates the thickness of the welded plate, in mm. This indicates the weld gap, in mm. This indicates the diameter of the welding wire, in mm. P represents laser output power, measured in kW; A, B, and C represent constants.

2. The laser filler wire welding weld formation control method according to claim 1, characterized in that, The thickness of the welding plate ranges from 0.6 to 3.0 mm.

3. The laser filler wire welding weld formation control method according to claim 1, characterized in that, The diameter of the welding wire is in the range of 0.8~1.2mm.

4. The laser filler wire welding weld formation control method according to claim 1, characterized in that, The weld gap is in the range of 0.1~0.7mm.

5. A laser filler wire welding weld formation control system for implementing the method according to any one of claims 1-4, characterized in that, This includes a welding wire control system, which is a welding wire straightening mechanism.

6. The laser filler wire welding weld formation control system according to claim 5, characterized in that, The welding wire straightening mechanism includes a wire quantity detection unit and a wire straightening unit. The wire quantity detection unit detects the wire feeding quantity and controls the wire feeding speed. The wire straightening unit straightens the welding wire.

7. A laser filler wire welding weld formation control system according to claim 5, characterized in that, It also includes a wire spool, wire feeding pipe, laser head, and weld gap signal acquisition module; The wire spool is connected to the input end of the wire control system for supplying welding wire; The output end of the welding wire control system is connected to the wire feeding pipe for conveying and straightening the welding wire; The weld gap signal acquisition module is set on the welding path in front of the wire feeding pipe. The signal output end of the weld gap signal acquisition module is connected to the control input end of the welding wire control system to acquire and provide weld gap signals in real time. The straightened welding wire enters the welding pool through the wire feeding pipe. Under the action of the laser head, it melts together with the steel plate base material to be welded to form a weld.

8. A laser filler wire welding weld formation control system according to claim 7, characterized in that, The end of the wire feeding pipe is equipped with a welding nozzle, which is used to guide the welding wire and feed it into the welding pool.

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