A laser-MIG arc hybrid welding arc length control method and system

Abstract

The present invention discloses a laser MIG arc hybrid welding arc length control method and system, including setting the process parameters, arc length control first range and arc length control second range in the arc hybrid welding process before arc hybrid welding; after arc hybrid welding starts, output welding current according to the process parameters, and perform wire retraction at a fixed frequency; during arc hybrid welding, obtain the voltage signal value during welding current output, integrate the peak voltage signal value of a single cycle, obtain the welding peak stage average voltage value, compare the deviation of the welding peak stage average voltage value with the given pulse peak stage average voltage value with the arc length control first range and arc length control second range, and then obtain the control strategy until arc hybrid welding is completed. The present invention can effectively reduce the interference of laser plasma on arc length, ensure the stability of arc length of laser MIG arc hybrid welding, and thus improve welding quality.

Description

Technical Field

[0001] The present invention relates to the technical field of laser welding, and in particular to a method and system for controlling arc length of laser-MIG arc hybrid welding. Background Art

[0002] Laser welding technology is an efficient and precise welding method, which is widely used in aerospace, automobile manufacturing, electronic appliances and other fields. The main principle of laser welding technology is to irradiate the surface of the workpiece with a high-energy laser beam, so that the workpiece material is quickly heated to a molten or gasified state, thereby realizing the connection of the workpiece. However, laser welding also has some limitations, such as thermal deformation and thermal cracks that are easy to occur during welding, and poor adaptability of weld gaps. Therefore, in order to improve welding quality and efficiency, technicians in this field began to explore hybrid welding technology that combines laser with other welding methods. In order to break through the limitations of laser welding technology, laser-MIG arc hybrid welding technology came into being. Laser-arc hybrid welding technology can fully combine the advantages of laser welding and arc welding, and has the advantages of large welding penetration, high efficiency, good joint bridging, narrow heat-affected zone, good quality and low cost.

[0003] The existing laser-MIG arc hybrid welding technology mainly combines laser welding with MIG arc welding, using the high energy density of the laser and the heat of the MIG arc to achieve efficient and stable welding. The existing laser-MIG arc hybrid welding technology usually adopts a constant welding current and voltage, and controls the welding process by adjusting the welding speed. The existing laser-CMT arc hybrid welding technology is conducive to the stability of the arc length during the welding process through a mechanical retraction method, but due to the limitation of the servo motor retraction frequency, its welding current and wire feeding speed are limited, and cannot meet the high-efficiency welding requirements of laser-MIG hybrid welding.

[0004] Precise control of the arc in the laser-MIG hybrid welding process is the key to high-quality welding. Although the existing laser-MIG arc hybrid welding technology has improved the welding quality and efficiency to a certain extent, there are still some problems. For example, since plasma is generated during the laser welding process, the plasma will compress and attract the welding arc, which will cause great interference to the feedback, collection, and judgment of the electrical parameters that characterize the arc length information (especially the pulse base value stage with poor arc stiffness), making it difficult to control the arc stability and affecting the welding process and quality. In addition, the existing welding power supply control technology is usually unable to accurately collect methods that characterize the arc length signal, and it is difficult to achieve sufficient stability during the welding process. Therefore, how to reduce the interference of plasma on arc control and how to accurately control the stability of the welding arc are key issues facing the current laser MIG arc hybrid welding technology. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a laser-MIG arc hybrid welding arc length control method and system, which reduces the interference of laser plasma on arc length control by combining voltage signal feedback with a mechanical arc length adjustment method. This processing method can effectively reduce the interference of laser plasma on the arc, ensure the stability of the arc length of laser-MIG arc hybrid welding, and thus improve the welding quality.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for controlling arc length of laser-MIG arc hybrid welding, comprising: before arc hybrid welding, setting process parameters, arc length control first range and arc length control second range in the arc hybrid welding process, wherein the process parameters include a given pulse peak stage average voltage value and a given current value, and matching a corresponding fixed welding current pulse output frequency, welding wire retraction frequency and retraction time for the given pulse peak stage average voltage value;

[0008] After arc hybrid welding starts, the welding current is output according to the process parameters, and the welding wire is retracted at a fixed frequency;

[0009] During the arc hybrid welding process, the voltage signal value during the welding current output period is obtained, the peak voltage signal value of a single cycle is integrated to obtain the average voltage value of the welding peak stage, and the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is calculated. The deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is compared with the first range of arc length control and the second range of arc length control, and then a control strategy is obtained until the arc hybrid welding is completed.

[0010] As a further technical solution, the process parameters also include given laser power and welding speed.

[0011] As a further technical solution, the pulse frequency, peak current, peak duration and base current of the arc welding control waveform are matched to the given current.

[0012] As a further technical solution, the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is compared with the first range of arc length control and the second range of arc length control to obtain a control strategy, including: if the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is greater than the second range of arc length control, the welding wire is retracted in the next pulse output cycle, and the welding wire retraction time is adjusted accordingly to adjust the arc length.

[0013] As a further technical solution, it also includes: if the deviation between the average voltage value in the welding peak stage and the average voltage value in the given pulse peak stage is less than the second range of the arc length control and greater than the first range of the arc length control, then the retraction time is adjusted during the wire retraction process of the next fixed welding current pulse output frequency.

[0014] As a further technical solution, it also includes: if the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is less than the first range of the arc length control, the retraction speed and the retraction time are not adjusted.

[0015] As a further technical solution, the calculation of the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is as follows: calculating the difference between the average voltage value of the welding peak stage and the given peak voltage value.

[0016] In a second aspect, the present invention provides a laser-MIG arc hybrid welding arc length control system, comprising the following modules:.

[0017] The parameter setting module is configured to: before arc hybrid welding, set the process parameters, arc length control first range and arc length control second range in the arc hybrid welding process, wherein the process parameters include the given pulse peak stage average voltage value, and match the given pulse peak stage average voltage value with the corresponding fixed welding current pulse output frequency, welding wire retraction frequency and retraction time;

[0018] The welding current output module is configured to: after arc hybrid welding starts, output welding current according to process parameters and retract the welding wire at a fixed frequency;

[0019] The control strategy output module is configured as follows: during the arc hybrid welding process, the voltage signal value during the welding current output period is obtained, the peak voltage signal value of a single cycle is integrated to obtain the average voltage value of the welding peak stage, and the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is calculated, and the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is compared with the first range of arc length control and the second range of arc length control, thereby obtaining a control strategy until the arc hybrid welding is completed.

[0020] One or more technical solutions of the present invention have the following beneficial effects:

[0021] (1) The present invention obtains the voltage signal value during the welding current output during the laser-MIG arc hybrid welding process, integrates the peak voltage signal value of a single cycle, and accurately compares it with the average voltage value of the given pulse peak stage. According to the comparison result, the withdrawal time and speed of the welding wire are adjusted in a timely and accurate manner (control strategy). In actual welding, when the thickness of the welding material is uneven or the welding environment changes, especially when the arc is disturbed and the base voltage value cannot accurately represent the arc length, this real-time adjustment method can enable the welding parameters to adapt to changes quickly, improve the flexibility and adaptability of the welding process and the arc stability, thereby improving the welding quality and efficiency.

[0022] (2) The present invention uses constant pulse frequency, peak current, peak duration, base current and other parameters to output welding current, and at the same time controls the welding wire to be withdrawn at 1 / 10 of the fixed welding current pulse output frequency. This control method can achieve precise control of the welding current, avoid the instability of the welding process caused by welding current fluctuations, simplify the calculation amount and logic complexity of the control system, and thus improve the welding quality and efficiency.

[0023] (3) The present invention effectively weakens the interference of laser plasma on arc control through a unique voltage signal feedback mechanism combined with an innovative method of mechanically adjusting arc length, breaking through the limitation of traditional solutions that only adjust arc length through electrical signal feedback. During the welding process, especially for the electronic and electrical industry that has extremely high requirements for arc stability, a stable arc length can ensure the quality consistency of the welded joint. For example, when welding tiny electronic component pins, a stable arc length can avoid problems such as cold solder joints and short circuits, thereby improving product reliability and performance. This reduction in interference ensures the stability of the arc length of the laser-MIG arc hybrid welding, thereby comprehensively improving the welding quality, reducing the scrap rate, and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0025] Figure 1 It is a flow chart of the arc length control method of laser-MIG arc hybrid welding of the present invention; DETAILED DESCRIPTION

[0026] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0027] Embodiment 1

[0028] This embodiment provides a method for controlling the arc length of laser-MIG arc hybrid welding. The existing laser-MIG arc hybrid welding equipment includes a fiber laser, a welding power supply, a hybrid welding gun with a servo motor capable of realizing retraction control, a wire feeding mechanism, a control system and other components, such as Figure 1 As shown in the flow chart of the control method, before arc hybrid welding, according to the properties and thickness of the materials to be welded and the welding requirements such as the welding joint, the process parameters, the first range of arc length control and the second range of arc length control in the arc hybrid welding process are set, wherein the process parameters include the average voltage value of a given pulse peak stage, a given laser power, a given current value, a welding speed, and the type and flow rate of shielding gas; according to the unified database in the control system, the corresponding fixed welding current pulse output frequency, welding wire retraction frequency, and retraction time and other parameters are matched for the average voltage value of the given pulse peak stage; and the pulse frequency, peak current, peak duration, base current and other parameters of the arc welding control waveform are matched for the given welding current. Specifically: before welding, the given laser power is 8000W to ensure sufficient energy input to melt the material to be welded; the given current value is 210A, which can not only ensure good penetration, but also avoid problems such as burn-through caused by excessive current; the given pulse peak stage average voltage value is 20V, which provides suitable voltage conditions for stable arc combustion; the welding speed is 1m / min, the shielding gas is 20% CO2-80% Ar, and the flow rate is 20L / min. CO2 gas helps to enhance arc stability and penetration, and Ar gas can prevent weld oxidation. The pulse frequency of the arc welding control waveform matched by the control system is 180Hz; the fixed welding current pulse output frequency is one tenth of the pulse frequency of the arc welding control waveform, that is, 18Hz; the peak current is 600A; the peak duration is 1.8ms, and the base current is 50A. The first range of arc length control is set to ±0.5V, and the second range is set to ±1V.

[0029] After arc hybrid welding starts, the welding current is output according to the process parameters. At the same time, the servo motor at the end of the welding gun is controlled to retract the welding wire at a fixed frequency (one tenth of the fixed welding current pulse output frequency, that is, 18Hz). At this time, the retraction speed is 25m / min, the retraction time is 3.85ms, and the arc height is about 5mm.

[0030] During the arc hybrid welding process, the voltage signal value during the welding current output period is obtained in real time, the peak voltage signal value of a single cycle is integrated to obtain the average voltage value of the welding peak stage, and the average voltage value of the welding peak stage is compared with the average voltage value of the given pulse peak stage, wherein the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is calculated, that is, the difference between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is calculated, and the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is compared with the first range of arc length control and the second range of arc length control, thereby obtaining a control strategy until the arc hybrid welding is completed. Specifically: if the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is greater than the second range of arc length control, the welding wire is retracted in the next pulse output cycle, and the retraction time is adjusted. For example, if the average voltage value of the welding peak stage is greater than 21V or less than 19V, the welding wire is retracted in the next pulse output cycle, and the retraction time is adjusted. Specifically, if the average voltage value of the welding peak stage is greater than 21V, it means that the welding arc is too high, and the wire retraction time will be reduced to reduce the arc height. If the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is less than the second range of the arc length control, and greater than the first range of the arc length control, the retraction time is adjusted during the wire retraction process of the next fixed welding current pulse output frequency. For example, if the average voltage value of the welding peak stage is 19V-19.5V or 20.5V-21V, the retraction time is adjusted during the wire retraction process of the next fixed welding current pulse output frequency. If the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is less than the first range of the arc length control, the retraction speed and retraction time are not adjusted. For example, if the average voltage value of the welding peak stage is 19.5-20.5V, it means that the welding arc height is within an acceptable range, and the retraction speed and retraction time are not adjusted. According to the difference between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage, the retraction time and speed of the welding wire are dynamically adjusted. This dynamic adjustment method can quickly adjust the height of the welding arc, effectively improve the stability of the welding process, and thus improve the welding quality and efficiency. The voltage signal value during the welding current output is obtained in real time and continuously, and the above comparison process is repeated until the welding process is completed. Through the above steps, the arc length of the laser MIG arc hybrid welding can be effectively controlled to improve the welding quality and efficiency. The laser-MIG arc hybrid welding arc length control method in this embodiment is not only applicable to laser-MIG arc hybrid welding, but also applicable to the regulation of other welding arcs in working conditions with severe arc interference. This wide applicability improves the practical value of the present invention.

[0031] Embodiment 2

[0032] This embodiment provides a laser-MIG arc hybrid welding arc length control system, including the following modules:.

[0033] The parameter setting module is configured to: before arc hybrid welding, set the process parameters, arc length control first range and arc length control second range in the arc hybrid welding process, wherein the process parameters include the given pulse peak stage average voltage value, and match the given pulse peak stage average voltage value with the corresponding fixed welding current pulse output frequency, welding wire retraction frequency and retraction time;

[0034] The welding current output module is configured to: after arc hybrid welding starts, output welding current according to process parameters and retract the welding wire at a fixed frequency;

[0035] The control strategy output module is configured as follows: during the arc hybrid welding process, the voltage signal value during the welding current output period is obtained, the peak voltage signal value of a single cycle is integrated to obtain the average voltage value of the welding peak stage, and the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is calculated, and the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is compared with the first range of arc length control and the second range of arc length control, thereby obtaining a control strategy until the arc hybrid welding is completed.

[0036] Embodiment 3

[0037] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps in the laser-MIG arc hybrid welding arc length control method described in the above-mentioned embodiment 1 are implemented.

[0038] Embodiment 4

[0039] This embodiment provides an electronic device, including a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, the steps in a laser-MIG arc hybrid welding arc length control method as described in Embodiment 1 are implemented.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for controlling arc length of laser-MIG arc hybrid welding, characterized in that: include: Before arc hybrid welding, set the process parameters, arc length control first range and arc length control second range in the arc hybrid welding process, wherein the process parameters include a given pulse peak stage average voltage value and a given current value, and match the given pulse peak stage average voltage value with a corresponding fixed welding current pulse output frequency, welding wire retraction frequency and retraction time; After arc hybrid welding starts, the welding current is output according to the process parameters, and the welding wire is retracted at a fixed frequency; During the arc hybrid welding process, the voltage signal value during the welding current output period is obtained, the peak voltage signal value of a single cycle is integrated to obtain the average voltage value of the welding peak stage, and the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is calculated. The deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is compared with the first range of arc length control and the second range of arc length control, and then a control strategy is obtained until the arc hybrid welding is completed.

2. A laser-MIG arc hybrid welding arc length control method as claimed in claim 1, characterized in that: The process parameters also include a given laser power and a welding speed.

3. A laser-MIG arc hybrid welding arc length control method as claimed in claim 1, characterized in that: And the pulse frequency, peak current, peak duration and base current of the arc welding control waveform are matched to the given current.

4. A laser-MIG arc hybrid welding arc length control method as claimed in claim 1, characterized in that: The deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is compared with the first range of arc length control and the second range of arc length control to obtain a control strategy, including: if the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is greater than the second range of arc length control, the welding wire is retracted in the next pulse output cycle, and the welding wire retraction time is adjusted accordingly to adjust the arc length.

5. A laser-MIG arc hybrid welding arc length control method as claimed in claim 4, characterized in that: Also includes: If the deviation between the average voltage value in the welding peak stage and the average voltage value in the given pulse peak stage is less than the second range of the arc length control and greater than the first range of the arc length control, the retraction time is adjusted during the wire retraction process of the next fixed welding current pulse output frequency.

6. A laser-MIG arc hybrid welding arc length control method as claimed in claim 4, characterized in that: Also includes: If the deviation between the average voltage value in the welding peak stage and the average voltage value in the given pulse peak stage is smaller than the first range of arc length control, the retraction speed and the retraction time are not adjusted.

7. A laser-MIG arc hybrid welding arc length control method as claimed in claim 1, characterized in that: The calculation of the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is as follows: the difference between the average voltage value of the welding peak stage and the given peak voltage value is calculated.

8. A laser-MIG arc hybrid welding arc length control system, characterized in that: Includes the following modules: The parameter setting module is configured to: before arc hybrid welding, set the process parameters, arc length control first range and arc length control second range in the arc hybrid welding process, wherein the process parameters include the given pulse peak stage average voltage value, and match the given pulse peak stage average voltage value with the corresponding fixed welding current pulse output frequency, welding wire retraction frequency and retraction time; The welding current output module is configured to: after arc hybrid welding starts, output welding current according to process parameters and retract the welding wire at a fixed frequency; The control strategy output module is configured as follows: during the arc hybrid welding process, the voltage signal value during the welding current output period is obtained, the peak voltage signal value of a single cycle is integrated to obtain the average voltage value of the welding peak stage, and the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is calculated, and the deviation between the average voltage value of the welding peak stage and the average voltage value of the given pulse peak stage is compared with the first range of arc length control and the second range of arc length control, thereby obtaining a control strategy until the arc hybrid welding is completed.

9. A computer-readable storage medium having a program stored thereon, characterized in that: When the program is executed by a processor, the steps in the laser-MIG arc hybrid welding arc length control method as described in any one of claims 1 to 7 are implemented.

10. An electronic device comprising a memory, a processor, and a program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps in the laser-MIG arc hybrid welding arc length control method as described in any one of claims 1 to 7 are implemented.

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