A constant arc length MIG welding method, system and electronic device

Abstract

The present application provides a kind of constant arc length MIG welding method, system and electronic equipment, it is related to MIG welding technical field, the method includes: in each welding cycle of MIG welding, pulse welding stage is executed, and arc detection stage is executed after pulse welding stage ends;For pulse welding stage, control wire is carried out pulse welding according to first wire feed speed combination with preset pulse parameter;For arc detection stage, by controlling wire to be fed to molten pool direction according to second wire feed speed while continuously collecting welding voltage, and based on welding voltage, the distance data between the end of wire and the surface of molten pool under welding cycle is obtained;Based on distance data, the target arc length of welding cycle and the preset compensation amount are combined to determine the retraction displacement of wire;According to retraction displacement, control wire according to execute reverse retraction action.The present application improves the stability and reset precision of arc length between the end of wire and the surface of molten pool.

Description

Technical Field

[0001] This invention relates to the field of MIG welding technology, and more specifically, to a constant arc length MIG welding method, system, and electronic equipment. Background Technology

[0002] In pulsed metal inert gas (MIG) welding of aluminum alloys, the dynamic stability of the molten pool is crucial to the weld formation quality. On one hand, the molten pool height is a direct indicator of whether the welding heat input is appropriate. On the other hand, the arc length between the welding wire tip and the molten pool surface directly determines the reliability of the welding process.

[0003] In related technologies, open-loop or semi-open-loop wire resetting methods are typically used to achieve periodic arc length reset by performing wire retraction and feeding actions at fixed intervals. However, when using large-diameter aluminum alloy welding wire (such as 1.6mm), its high rigidity, high wire feeding resistance, and low electrical resistance result in weak arc self-adjustment capability. During welding, arc length drift is prone to occur due to changes in the molten pool height, leading to insufficient arc length reset accuracy and consequently affecting the weld formation quality. Summary of the Invention

[0004] The problem addressed by this invention is how to improve the arc length stability between the welding wire tip and the surface of the molten pool.

[0005] To address the above problems, this invention provides a constant arc length MIG welding method, system, and electronic device.

[0006] In a first aspect, the present invention provides a constant arc length MIG welding method, comprising: In each welding cycle of MIG welding, a pulse welding phase is performed, and after the pulse welding phase ends, an arc detection phase is performed until the welding cycle ends. Specifically, in the pulse welding stage, the welding wire is controlled to perform pulse welding according to the first wire feeding speed, combined with preset pulse parameters. During the arc detection phase, the welding wire is fed towards the molten pool at a second wire feeding speed while the welding voltage is continuously collected. Based on the welding voltage, the distance data between the welding wire tip and the molten pool surface during the welding cycle is obtained, wherein the first wire feeding speed is less than the second wire feeding speed. Based on the distance data, combined with the target arc length of the welding cycle and a preset compensation amount, the retraction displacement of the welding wire is determined. According to the retraction displacement, the welding wire is controlled to perform a reverse retraction action until the retraction distance of the welding wire reaches the retraction displacement. At the end of the reverse retraction action, the welding wire tip and the molten pool surface are electrically and physically separated.

[0007] Optionally, the step of performing a pulse welding phase in each welding cycle of MIG welding, and performing an arc detection phase after the pulse welding phase ends, until the welding cycle ends, includes: For the current welding cycle, first execute the preset number of pulse welding stages under the current welding cycle; After all the pulse welding stages have been completed, the arc detection stage of the current welding cycle is executed until the current welding cycle ends.

[0008] Optionally, the control of the welding wire according to a first wire feeding speed, combined with preset pulse parameters, includes pulse welding, including: In the pulse welding phase of each welding cycle, the peak current and base current of the welding cycle are determined according to the preset pulse parameters. The welding power supply is controlled to output according to the peak current and the base current, and the welding wire is controlled to be fed at a constant speed according to the first wire feeding speed until the pulse welding stage ends.

[0009] Optionally, the step of controlling the welding wire to feed towards the molten pool at a second wire feeding speed, while continuously acquiring the welding voltage, and obtaining the distance data between the welding wire tip and the molten pool surface during the welding cycle based on the welding voltage, includes: The welding wire is controlled to feed towards the molten pool at the second wire feeding speed, and the welding voltage is continuously collected; Based on the welding voltage, determine whether the end of the welding wire comes into contact with the surface of the molten pool; When the tip of the welding wire comes into contact with the surface of the molten pool, the feeding of the welding wire toward the molten pool is stopped, and the time taken from the welding wire being fed at the second wire feeding speed until the tip of the welding wire comes into contact with the surface of the molten pool is obtained, and the time taken is used as the height detection time. Based on the first wire feeding speed, the second wire feeding speed, and the height detection time, the distance data between the end of the welding wire and the surface of the molten pool is determined.

[0010] Optionally, determining whether the welding wire tip contacts the molten pool surface based on the welding voltage includes: Based on the welding voltage, a comparison is made with a preset short-circuit voltage threshold to determine whether the end of the welding wire comes into contact with the surface of the molten pool. Specifically, when the welding voltage is less than the short-circuit voltage threshold, it is determined that the end of the welding wire is in contact with the surface of the molten pool; When the welding voltage is greater than or equal to the short-circuit voltage threshold, it is determined that the end of the welding wire is not in contact with the surface of the molten pool.

[0011] Optionally, determining the distance data between the welding wire tip and the molten pool surface based on the first wire feeding speed, the second wire feeding speed, and the height detection time includes: Obtain the speed difference between the second wire feeding speed and the first wire feeding speed; Multiply the speed difference by the height detection time to obtain the distance data between the end of the welding wire and the surface of the molten pool.

[0012] Optionally, determining the retraction displacement of the welding wire based on the distance data, combined with the target arc length of the welding cycle and a preset compensation amount, includes: The distance data, the target arc length, and the preset compensation amount are added together to obtain the total length. The sum of the lengths is taken as the retraction displacement of the welding wire.

[0013] Optionally, the step of controlling the welding wire to perform a reverse retraction action according to the retraction displacement until the retraction distance of the welding wire reaches the retraction displacement, and performing electrical and physical separation of the welding wire end from the molten pool surface at the end of the reverse retraction action, includes: The welding wire is controlled to perform a reverse retraction action at a preset retraction speed until the retraction distance of the welding wire reaches the retraction displacement; At the end of the reverse retraction action, the welding power supply is controlled to output a droplet separation current to perform electrical and physical separation between the welding wire tip and the surface of the molten pool. The droplet separation current is a preset ratio of the peak current of the welding cycle, and the amplitude of the droplet separation current is less than the peak current but greater than the base current of the welding cycle.

[0014] In a second aspect, the present invention provides a constant arc length MIG welding system, comprising: The welding control unit is used to perform a pulse welding phase in each welding cycle of MIG welding, and to perform an arc detection phase after the pulse welding phase ends, until the welding cycle ends. The pulse welding subunit is used to control the welding wire to perform pulse welding according to the first wire feeding speed and in combination with preset pulse parameters for the pulse welding stage. The detection subunit is used for the arc detection stage to control the welding wire to feed towards the molten pool at a second wire feeding speed, while continuously acquiring the welding voltage, and based on the welding voltage, to obtain the distance data between the tip of the welding wire and the surface of the molten pool during the welding cycle, wherein the first wire feeding speed is less than the second wire feeding speed; based on the distance data, combined with the target arc length of the welding cycle and a preset compensation amount, to determine the retraction displacement of the welding wire; according to the retraction displacement, to control the welding wire to perform a reverse retraction action until the retraction distance of the welding wire reaches the retraction displacement, and at the end of the reverse retraction action, to perform electrical separation and physical separation between the tip of the welding wire and the surface of the molten pool.

[0015] Thirdly, the present invention provides an electronic device, comprising: a processor and a memory, wherein the memory is used to store a computer program; When the computer program is loaded by the processor, it causes the processor to execute the constant arc length MIG welding method described above.

[0016] The constant arc length MIG welding method, system, and electronic equipment of this invention achieve temporal decoupling and functional separation of the welding operation process and the autonomous arc length control process by sequentially arranging the pulse welding stage and the arc detection stage within each welding cycle, thus establishing a basic temporal framework for stable control of the entire constant arc length. In the pulse welding stage, constant feed pulse welding is carried out by synchronously matching the first wire feed speed with preset pulse parameters, ensuring a regular droplet transition morphology and uniform and stable basic heat input during welding. In the arc detection stage, a second wire feed speed greater than the first wire feed speed is used to control the rapid feeding of the welding wire towards the molten pool. Simultaneously, welding voltage is continuously acquired throughout the process, and the real-time identification and perception of the molten pool height and gap distance are completed based on the voltage signal characteristics, overcoming the technical limitations of traditional methods that cannot accurately obtain the real-time state of the molten pool surface and the welding wire gap information. Furthermore, by combining the measured distance data, the preset target arc length of the welding cycle, and the preset compensation amount for process adaptation, the welding wire retraction displacement is calculated collaboratively. The compensation amount is introduced to correct the inherent deviations caused by mechanical transmission, molten pool morphology, and welding wire rigidity, ensuring the welding wire... The retraction action can adapt to the current molten pool height and the actual arc length deviation, completing the numerical and precise quantitative correction of the arc length. According to the calculated retraction displacement, the welding wire is controlled to perform a quantitative reverse retraction action until the actual retraction distance accurately matches the set retraction displacement. This can offset various arc length errors existing in the current cycle and accurately calibrate the welding wire end position to the target process position. After the reverse retraction action is in place, the electrical and physical separation between the welding wire end and the molten pool surface is completed simultaneously, eliminating abnormal conditions such as wire adhesion and continuous short circuit interference. This ensures that the arc length gap is clean and regular before arc ignition in each cycle, forming a complete closed-loop control link for the entire welding cycle. For large-diameter aluminum alloy welding wires, which have high rigidity, high wire feeding resistance, low equivalent resistance, and weak inherent arc adjustment capability, making them prone to arc length drift due to molten pool fluctuations, the retraction stroke and separation state can be adaptively adjusted in real time according to the dynamic changes in molten pool height. This continuously suppresses the arc length deviation caused by various disturbance factors, improving the consistency, stability, and accuracy of arc length reset between the welding wire end and the molten pool surface. Attached Figure Description

[0017] Figure 1 This is a schematic flowchart of the constant arc length MIG welding method according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the constant arc length MIG welding control timing according to another embodiment of the present invention; Figure 3 This is a self-test timing diagram of another embodiment of the present invention; Figure 4 This is a schematic diagram of the welding apparatus according to another embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of a constant arc length MIG welding system according to another embodiment of the present invention. Detailed Implementation

[0018] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0019] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0020] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0021] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0022] Combination Figure 1 As shown, the constant arc length MIG welding method provided in this embodiment of the invention includes: In each welding cycle of MIG welding, a pulse welding phase is performed, and after the pulse welding phase ends, an arc detection phase is performed until the welding cycle ends.

[0023] Specifically, the complete welding process is divided into a periodic pulse welding stage and an arc detection stage, realizing the temporal separation of the welding heat input process and the arc length control process, so that the two stages can operate independently, establishing a clear and repeatable control framework for stable arc length control, and avoiding arc length disturbances and drifts caused by welding and control coupling from the process structure perspective.

[0024] Specifically, in the pulse welding stage, the welding wire is controlled to perform pulse welding according to a first wire feeding speed, combined with preset pulse parameters.

[0025] Specifically, the pulse welding stage uses preset pulse parameters to perform stable welding, and synchronously controls the welding wire to maintain a constant feed speed at a fixed first wire feed speed, so that the welding heat input remains uniform and controllable. This ensures that the molten droplets can achieve orderly transition according to a stable rhythm during the welding process, maintain the relative stability of the molten pool shape and height, and avoid problems such as fluctuating heat input and uneven droplet transition caused by fluctuations in wire feed speed and disordered pulse parameters.

[0026] During the arc detection phase, the welding wire is fed towards the molten pool at a second wire feeding speed while the welding voltage is continuously collected. Based on the welding voltage, the distance data between the welding wire tip and the molten pool surface during the welding cycle is obtained, wherein the first wire feeding speed is less than the second wire feeding speed. Based on the distance data, combined with the target arc length of the welding cycle and a preset compensation amount, the retraction displacement of the welding wire is determined. According to the retraction displacement, the welding wire is controlled to perform a reverse retraction action until the retraction distance of the welding wire reaches the retraction displacement. At the end of the reverse retraction action, the welding wire tip and the molten pool surface are electrically and physically separated.

[0027] Specifically, the arc detection stage, as the control stage for achieving adaptive constant arc length closed-loop control in this invention, differs from the steady-state wire feeding process of the pulse welding stage. It employs a second wire feeding speed, greater than the first, to drive the welding wire rapidly towards the molten pool. Simultaneously, high-frequency, continuous acquisition of real-time welding voltage signals is performed throughout the wire feeding process. Based on the characteristics of welding voltage variation with arc gap and short-circuit conditions, the actual distance data between the welding wire tip and the molten pool surface during the welding cycle is obtained, enabling quantitative perception of the real-time height of the molten pool and the arc gap state. After obtaining accurate distance data, adjustments are not made solely based on measured data. Instead, a comprehensive calculation is performed, combining the preset standard target arc length for the current welding cycle with preset compensation amounts calibrated to adapt to welding wire rigidity, mechanical transmission errors, and molten pool surface morphology changes, to correct the welding conditions and mechanical structure. The inherent deviation is calculated to determine the wire retraction displacement that adapts to the current real-time state of the molten pool, achieving quantitative and adaptive correction of the arc length deviation. Subsequently, the wire is driven to perform a reverse retraction action until the actual retraction distance perfectly matches the calculated retraction displacement, offsetting the arc length drift and position deviation generated in the current cycle and completing the reset of the wire end position. Finally, the wire end and the molten pool surface are simultaneously separated by both electrical and physical separation, completely eliminating metal adhesion, residual conductive circuits, and micro-connection structures between the wire end and the molten pool, preventing short-circuit residues, wire adhesion, unstable arc ignition, and other problems. This ensures that the arc gap is regular and clean after each welding cycle, providing accurate and reliable initial arc length conditions for stable arc ignition and uniform droplet transfer in the next welding cycle, and achieving periodic dynamic calibration and constant control of the welding arc length.

[0028] The constant arc length MIG welding method of this invention achieves temporal decoupling and functional separation between the welding operation process and the autonomous arc length control process by sequentially arranging the pulse welding stage and the arc detection stage within each welding cycle, thus establishing a basic temporal framework for stable control of the entire constant arc length. In the pulse welding stage, constant feed pulse welding is carried out by synchronously matching the first wire feed speed with preset pulse parameters, ensuring a regular droplet transition morphology and uniform and stable basic heat input during welding. In the arc detection stage, a second wire feed speed greater than the first wire feed speed is used to control the rapid feeding of the welding wire towards the molten pool. Simultaneously, welding voltage is continuously collected throughout the process, and the molten pool height and gap distance are identified and perceived in real time based on the voltage signal characteristics, overcoming the technical limitations of traditional methods that cannot accurately obtain the real-time state of the molten pool surface and the welding wire gap information. Furthermore, by combining the measured distance data, the preset target arc length of the welding cycle, and the preset compensation amount for process adaptation, the welding wire retraction displacement is calculated collaboratively. The compensation amount is introduced to correct the inherent deviations caused by mechanical transmission, molten pool morphology, and welding wire rigidity, thus enabling the welding wire retraction action... It can adapt to the current molten pool height and the actual arc length deviation, and complete the numerical and precise quantitative correction of the arc length. According to the calculated retraction displacement, it controls the welding wire to perform a quantitative reverse retraction action until the actual retraction distance accurately matches the set retraction displacement. This can offset various arc length errors existing in the current cycle and accurately calibrate the welding wire end position to the target process position. After the reverse retraction action is in place, it simultaneously completes the electrical and physical separation between the welding wire end and the molten pool surface, eliminating abnormal conditions such as wire adhesion and continuous short circuit interference. It ensures that the arc length gap is clean and regular before arc ignition in each cycle, forming a complete closed-loop control link for the entire welding cycle. For large-diameter aluminum alloy welding wires, which have high rigidity, high wire feeding resistance, low equivalent resistance, and weak inherent arc adjustment capability, making them prone to arc length drift with molten pool fluctuations, it can dynamically adjust the retraction stroke and separation state in real time according to the dynamic changes in molten pool height. It continuously suppresses the arc length deviation caused by various disturbance factors, improves the consistency and stability of arc length operation between the welding wire end and the molten pool surface, and enhances the accuracy of cycle arc length reset.

[0029] Optionally, the step of performing a pulse welding phase in each welding cycle of MIG welding, and performing an arc detection phase after the pulse welding phase ends, until the welding cycle ends, includes: For the current welding cycle, first execute the preset number of pulse welding stages under the current welding cycle; After all the pulse welding stages have been completed, the arc detection stage of the current welding cycle is executed until the current welding cycle ends.

[0030] Specifically, in the pulsed MIG welding process of aluminum alloys, the complete welding process is divided into continuous cyclic welding cycles. Each welding cycle proceeds sequentially according to a fixed order: first, the pulse welding stage, then the arc detection stage. The pulse welding stage mainly completes the droplet transfer and heat input / output under preset parameters, while the arc detection stage is used to complete the detection of the molten pool height, wire retraction, and arc length reset. The two stages are independent in timing but sequentially connected. The arc detection stage of the same cycle can only begin after the pulse welding stage is completed. The current welding cycle ends when all arc detection stages are completed. Subsequent welding processes then cycle through the next welding cycle according to the same timing rules until the entire welding process is completed. This timing setting method is compatible with the droplet transfer law, dynamic changes in the molten pool, and the action logic of wire feeding and retraction in pulsed MIG welding, providing a standardized and reliable timing basis for molten pool status detection, arc length closed-loop control, and stable operation of the welding process. Figure 2 As shown, each welding cycle T is divided into a pulse welding stage Tp and an arc detection stage Ts. The pulse welding stage Tp ensures a stable droplet transition, while the arc detection stage Ts detects the molten pool height and resets the arc length. Independent control of these two stages allows for precise regulation of heat input and arc length. Furthermore, the insertion frequency of the arc detection stage Ts can be flexibly adjusted. It can be inserted after every pulse welding stage Tp, or once every N pulse welding stages (N ranging from 1 to 20), balancing welding real-time performance and stability. For the dual-pulse mode, different insertion ratios of the arc detection stage Ts can be used in high-energy and low-energy cycles. In high-energy cycles, one Ts is inserted after every 9 Tp stages to avoid excessive heat input. In low-energy cycles, four Ts are inserted after every 4 Tp stages. By increasing the frequency of Ts occurrence, heat input is reduced, while frequent arc length resets maintain arc stability, resulting in a clear and uniform fish-scale weld bead pattern.

[0031] It is worth mentioning that, in order to eliminate problems such as slippage and hysteresis in the wire feeding system and to ensure the accuracy of weld pool height detection and arc length control, a pre-welding self-inspection can be performed before welding begins, combined with... Figure 3 As shown, firstly, at a preset detection speed V test Feed the wire forward until it contacts the base material, and record the position of the welding wire at this point; control the welding wire to retract in the reverse direction to a preset height, and record the retraction time T-t1. Then, check the speed V again. test Feed the wire forward until it contacts the base material, and record the position of the welding wire at this point. Record the retraction time T-t2 (t1 and t2 are the running times corresponding to each retraction stroke). Calculate the error ΔE between the two positions: ΔE = |(T-t1)-(T-t2)|×V testRepeat the self-inspection process multiple times to calculate the average value of ΔE. If the average value of the error ΔE is ≤0.2mm, the wire feeding system is considered qualified and welding can proceed; otherwise, an alarm is triggered, prompting maintenance of the wire feeding system.

[0032] In this embodiment of the invention, by standardizing the execution sequence of each stage within the welding cycle, the welding process and the arc length control process can be decoupled in an orderly manner, effectively improving the stability and consistency of the welding control process, providing a reliable guarantee for real-time detection of the molten pool height and closed-loop constant arc length control, and thus significantly improving the stability of the arc length between the welding wire tip and the molten pool surface.

[0033] Optionally, the control of the welding wire according to a first wire feeding speed, combined with preset pulse parameters, includes pulse welding, including: In the pulse welding phase of each welding cycle, the peak current and base current of the welding cycle are determined according to the preset pulse parameters. The welding power supply is controlled to output according to the peak current and the base current, and the welding wire is controlled to be fed at a constant speed according to the first wire feeding speed until the pulse welding stage ends.

[0034] Specifically, within the pulse welding phase of each welding cycle, the peak current and base current are determined based on preset pulse parameters to ensure a single droplet per pulse during pulse welding. The peak current and base current are the electrical parameters required for single-droplet transfer in pulsed MIG welding. After the parameters are determined, the welding power supply is controlled to alternately output the determined peak current and base current to form a stable pulse welding arc. Simultaneously, the welding wire is controlled to maintain a constant feed rate at a predetermined first wire feed speed, ensuring a stable match between the wire feed speed and the pulse electrical parameters until the current pulse welding phase reaches its preset duration and ends normally. The first wire feed speed V1 corresponding to the welding cycle (typically ranging from 3 to 8 m / min, preferably 4.5 m / min) is the conventional stable wire feed speed during the welding process, determined by the base material, thickness, and welding current. The above control method can fully adapt to the droplet transfer characteristics of pulsed MIG welding of aluminum alloys, and is especially suitable for welding conditions of large rigid aluminum alloy welding wires with a diameter of 1.6mm. It can ensure stable droplet transfer and stable output of basic heat input. For example, when using a 1.6mm diameter aluminum alloy welding wire to perform pulsed MIG welding on 6061 aluminum alloy base material, in the pulse welding stage of each welding cycle, the first wire feed speed is determined to be V1=5.0 m / min, the peak current Ipp is 320A, and the base current Ipb is 90A according to the preset pulse parameters. Then, the welding power supply is controlled to periodically alternate between the peak current of 320A and the base current of 90A to form a stable pulse welding waveform. At the same time, the welding wire is controlled to maintain a constant positive feed speed of 5.0m / min to ensure stable droplet transfer of one pulse at a time. This is continued until the pulse welding stage ends and the process switches to the arc detection stage.

[0035] In this embodiment of the invention, by synergistically outputting stable electrical parameters and wire feed speed, uniform droplet transition and stable heat input can be ensured during the pulse welding stage, suppressing arc length fluctuations from the source and providing a stable prerequisite for subsequent arc length closed-loop control.

[0036] Optionally, the step of controlling the welding wire to feed towards the molten pool at a second wire feeding speed, while continuously acquiring the welding voltage, and obtaining the distance data between the welding wire tip and the molten pool surface during the welding cycle based on the welding voltage, includes: The welding wire is controlled to feed towards the molten pool at the second wire feeding speed, and the welding voltage is continuously collected; Based on the welding voltage, determine whether the end of the welding wire comes into contact with the surface of the molten pool; When the tip of the welding wire comes into contact with the surface of the molten pool, the feeding of the welding wire toward the molten pool is stopped, and the time taken from the welding wire being fed at the second wire feeding speed until the tip of the welding wire comes into contact with the surface of the molten pool is obtained, and the time taken is used as the height detection time. Based on the first wire feeding speed, the second wire feeding speed, and the height detection time, the distance data between the end of the welding wire and the surface of the molten pool is determined.

[0037] Specifically, the welding wire is first fed rapidly towards the molten pool at a second feeding speed greater than the first wire feeding speed. Simultaneously, welding voltage signals are acquired in real-time using high-frequency sampling. The characteristics of the welding voltage changes are used to determine whether the welding wire tip has made contact with the molten pool surface. When contact is confirmed, the wire feeding is immediately stopped. The time elapsed from the start of feeding at the second wire feeding speed to contact with the molten pool surface is accurately recorded and used as the height detection duration. Then, based on the first wire feeding speed, the second wire feeding speed, and the height detection duration, the distance between the welding wire tip and the molten pool surface is determined through a mathematical relationship between these speeds. In summary, this embodiment eliminates the need for external sensors such as vision or lasers, relying entirely on the welding equipment's own wire feeding mechanism and voltage sampling module to complete distance detection. It also effectively avoids interference from harsh welding environments such as arc light, spatter, and fumes, offering fast response, strong anti-interference capabilities, and high detection accuracy. It can accurately acquire distance data reflecting the real-time height of the molten pool.

[0038] In this embodiment of the invention, by adopting a rapid wire feeding combined with voltage sampling for molten pool height detection, accurate quantitative detection of the distance between the wire tip and the molten pool surface can be achieved without increasing any hardware costs. This effectively solves the problems of traditional detection methods being susceptible to interference from the welding environment, insufficient detection accuracy, and inability to quantitatively obtain molten pool height information.

[0039] Optionally, determining whether the welding wire tip contacts the molten pool surface based on the welding voltage includes: Based on the welding voltage, a comparison is made with a preset short-circuit voltage threshold to determine whether the end of the welding wire comes into contact with the surface of the molten pool. Specifically, when the welding voltage is less than the short-circuit voltage threshold, it is determined that the end of the welding wire is in contact with the surface of the molten pool; When the welding voltage is greater than or equal to the short-circuit voltage threshold, it is determined that the end of the welding wire is not in contact with the surface of the molten pool.

[0040] Specifically, relying on the welding voltage collected in real time during the welding process as a sensing signal, a short-circuit voltage threshold adapted to the aluminum alloy pulsed MIG welding condition is preset as a judgment benchmark. The real-time collected welding voltage value is compared and identified with the preset short-circuit voltage threshold in real time. Utilizing the electrical characteristics that the arc maintains a normal arc voltage when the welding wire tip is not in contact with the molten pool, and that the voltage drops sharply once the tip touches the molten pool surface and a short circuit is formed, a clear binary judgment logic is constructed. When the real-time welding voltage value is less than the preset short-circuit voltage threshold U... short When the voltage range is typically 3-8 V, preferably 5 V, it can be accurately determined that the welding wire tip and the molten pool surface have made physical contact and formed an electrical short circuit. When the real-time welding voltage is greater than or equal to the preset short-circuit voltage threshold, it is determined that the welding wire tip and the molten pool surface still maintain an arc gap and have not made contact. This determination logic can be achieved entirely by relying on the welding system's own voltage sampling circuit. Figure 2 As shown in the welding voltage waveform, during the pulse welding stage Tp, the voltage exhibits a periodic pulse fluctuation pattern with the alternating output of peak current and base current, maintaining a stable arc voltage range. After entering the arc detection stage Ts, as the wire feed speed switches to the second wire feed speed and rapidly feeds towards the molten pool, the welding voltage remains at the arc voltage level until the moment the welding wire tip contacts the surface of the molten pool. At this moment, the voltage drops sharply below the short-circuit voltage threshold, which is manifested in the waveform as a sharp voltage dip pulse, providing a clear trigger node for the accurate timing of the height detection duration T1. In a preferred embodiment of the present invention, during pulsed MIG welding of 6061 aluminum alloy sheet using 1.6mm diameter aluminum alloy welding wire, when the welding cycle enters the arc detection stage, the welding wire is fed rapidly from a first wire feed speed of 5.0m / min to a second wire feed speed of 10m / min and fed towards the molten pool. Simultaneously, the welding voltage is continuously collected at a sampling frequency of not less than 10kHz. When the welding voltage drops from the normal arc voltage to the short-circuit voltage threshold of 5V, it is determined that the tip of the welding wire has contacted the surface of the molten pool and the wire feed is immediately stopped. The time consumed from starting the second wire feed speed to contacting the molten pool is recorded as 8ms and used as the height detection time. Subsequently, the distance data between the tip of the welding wire and the surface of the molten pool under the current welding cycle is calculated based on the first wire feed speed of 5.0m / min, the second wire feed speed of 10m / min, and the height detection time of 8ms. This data serves as a quantitative characterization of the relative height of the molten pool.

[0041] In this embodiment of the invention, contact state identification is achieved by comparing the welding voltage with a preset short-circuit voltage threshold. The state judgment is completed based on the inherent electrical parameters of the welding process, eliminating the configuration and debugging costs of additional hardware detection devices. The structure is simple and highly adaptable, effectively avoiding interference from harsh environments such as strong arc light, welding fumes, and high-temperature spatter during aluminum alloy pulsed MIG welding. It avoids problems such as identification deviation, false triggering, and response lag that are common in traditional visual recognition methods. The voltage signal sampling response speed is fast, and the judgment logic is clear and solidified. It can accurately capture the contact time between the welding wire tip and the surface of the molten pool in real time, providing a reliable timing trigger reference for subsequent height detection duration timing, molten pool distance data calculation, and welding wire retraction displacement adjustment, effectively improving the stability and accuracy of the overall welding control.

[0042] Optionally, determining the distance data between the welding wire tip and the molten pool surface based on the first wire feeding speed, the second wire feeding speed, and the height detection duration includes: Obtain the speed difference between the second wire feeding speed and the first wire feeding speed; Multiply the speed difference by the height detection time to obtain the distance data between the end of the welding wire and the surface of the molten pool.

[0043] Specifically, in combination Figure 2 As shown, the welding wire is fed at a constant first wire feed speed Ws1. The welding power supply outputs alternating peak current Ipp and base current Ppb pulse waveforms to achieve stable droplet transfer. During the arc detection phase Ts, specifically the arc circuit detection period (Ts1 interval), after the pulse welding phase Tp ends, the welding current rapidly decreases to the arc-maintaining current (typically 20-80A, preferably 50A), and the wire feed speed switches from the first wire feed speed V1 to the second wire feed speed V2 (typically 1.5-3 times V1, preferably 2 times V1) and remains constant. The welding voltage U is sampled in real time. When the welding wire tip is determined to contact the molten pool surface, the time T1 from the start of rapid wire feeding to contact with the molten pool is recorded, i.e., the height detection time. The formula for calculating the relative height of the molten pool based on the first wire feed speed, the second wire feed speed, and the height detection time is: H pool =(V2 V1)×T1; where H pool This refers to the distance between the tip of the welding wire and the surface of the molten pool. After the welding wire contacts the molten pool, during the short-circuit maintenance and cooling period in the arc detection phase Ts (i.e., the Ts2 interval), wire feeding is stopped or fed at an extremely slow speed (e.g., 0.1 m / min) to maintain the short-circuit state between the welding wire and the molten pool. The welding current is maintained at the arc-maintaining current for the preset cooling time T. cool(The range is usually 0.5~5 ms, preferably 2 ms) to allow the molten pool to cool down appropriately, reduce heat input, and avoid the molten pool cooling too quickly, which could cause the wire to stick.

[0044] In this embodiment of the invention, by calculating the speed difference and time, the detection results can truly reflect the real-time dynamic changes of the molten pool, providing reliable data support for constant arc length control. The above calculation method is logically simple and easy to implement in the programming of the welding controller. It does not require external precision detection devices such as laser sensors and visual imaging. It can complete the quantitative solution of distance data by relying only on the wire feeding speed regulation function and voltage sampling module of the equipment itself, effectively avoiding the interference problems caused by harsh working conditions such as strong arc light, high temperature fumes, and metal spatter during the welding process on the sensing detection.

[0045] Optionally, determining the retraction displacement of the welding wire based on the distance data, combined with the target arc length of the welding cycle and a preset compensation amount, includes: The distance data, the target arc length, and the preset compensation amount are added together to obtain the total length. The sum of the lengths is taken as the retraction displacement of the welding wire.

[0046] Specifically, after accurately acquiring the distance data between the welding wire tip and the molten pool surface, the traditional fixed timing and fixed stroke retraction setting is no longer used. Instead, the measured distance data, the target arc length preset for the welding cycle, and the compensation amount pre-calibrated to adapt to the welding conditions are linearly superimposed. The sum of these three data points is then obtained, and the total length is directly determined as the retraction displacement required for the welding wire in this action. The compensation amount can be adaptively calibrated based on the rigidity characteristics of the large-diameter aluminum alloy welding wire, the transmission clearance of the wire feeding mechanism, the surface tension effect of the liquid metal on the molten pool surface, and the slight positional deviation caused by welding thermal deformation. This can compensate for mechanical transmission errors, molten pool morphology disturbances, and positional deviations caused by the elastic deformation of the welding wire itself. By incorporating a comprehensive correction amount that integrates process characteristics and mechanical characteristics, a matching retraction stroke can be dynamically generated for the real-time fluctuations in the molten pool height of each welding cycle, thus overcoming the limitation that a fixed retraction amount under open-loop control cannot adapt to random changes in the molten pool. In a preferred embodiment of the present invention, during pulsed MIG welding of aluminum alloy components using 1.6mm diameter aluminum alloy welding wire, the distance between the end of the welding wire and the surface of the molten pool, obtained through the molten pool height detection operation, is 1.8mm. The target arc length preset for the current welding cycle is 2.0mm. Simultaneously, considering the rigidity of this welding wire and the characteristics of the wire feeding mechanism, a pre-calibrated compensation amount of 0.3mm is calculated. The sum of these three values ​​is 4.1mm. This 4.1mm length is then directly used as the retraction displacement required for the welding wire in this welding cycle. The control system drives the wire feeding mechanism to complete the reverse retraction action according to this displacement, achieving precise reset and adjustment of the arc length. In another preferred embodiment of the present invention, combined with... Figure 2 As shown, during the adaptive retraction and arc length reset phase in the arc detection stage Ts, i.e., the Ts3 interval, the process is based on the target arc length L1 and the currently measured relative height H of the molten pool. pool Dynamically adjust the wire retraction speed Ws3 (typically ranging from 6 to 15 m / min, preferably 10 m / min) and / or retraction time; calculate the required retraction displacement using the formula: L retract =L arctarget +H pool +Δcomp; where Δcomp is a preset compensation amount used to compensate for the influence of factors such as the shape of the welding wire tip and the surface tension of the molten pool, typically 0.5mm, L arctarget For the target arc length (which typically ranges from 3 to 8 mm, preferably 5 mm), L retract This is the pullback displacement.

[0047] In this embodiment of the invention, the retraction displacement is determined by summing the measured distance data, the target arc length, and the preset compensation amount. The corresponding retraction stroke is dynamically matched according to the real-time change of the molten pool height in each welding cycle. At the same time, the preset compensation amount effectively offsets the positional deviation caused by the rigid deformation of the large-diameter aluminum alloy welding wire, the transmission gap of the wire feeding mechanism, the undulation of the molten pool surface, and the welding thermal stress. This significantly reduces the error in setting the retraction displacement, enabling the welding wire retraction action to accurately match the current actual arc length deviation. This effectively suppresses the arc length drift phenomenon that easily occurs during welding, thereby reducing welding defects such as spatter, arc breakage, and uneven penetration caused by arc length fluctuations. This comprehensively improves the stability of the pulsed MIG welding process and the overall weld formation quality.

[0048] Optionally, the step of controlling the welding wire to perform a reverse retraction action according to the retraction displacement until the retraction distance of the welding wire reaches the retraction displacement, and performing electrical and physical separation of the welding wire end from the molten pool surface at the end of the reverse retraction action, includes: The welding wire is controlled to perform a reverse retraction action at a preset retraction speed until the retraction distance of the welding wire reaches the retraction displacement; At the end of the reverse retraction action, the welding power supply is controlled to output a droplet separation current to perform electrical and physical separation between the welding wire tip and the surface of the molten pool. The droplet separation current is a preset ratio of the peak current of the welding cycle, and the amplitude of the droplet separation current is less than the peak current but greater than the base current of the welding cycle.

[0049] Specifically, after determining the precise retraction displacement based on distance data, target arc length, and compensation amount, firstly, relying on the wire feeding drive mechanism of the welding equipment, the welding wire is controlled to smoothly execute a reverse retraction action at a pre-set fixed retraction speed, maintaining a uniform retraction speed throughout the process. The retraction action stops immediately after the actual movement of the welding wire perfectly matches the preset retraction displacement. At the exact moment the reverse retraction action of the welding wire ends, the output of the welding power supply is simultaneously adjusted to ensure that the welding power supply outputs a droplet separation current that matches the process requirements. This droplet separation current is approximately 50% of the peak current, helping to cleanly separate the welding wire from the molten pool and preventing wire adhesion. In this embodiment of the invention, the preset ratio can be 0.5. By utilizing the electrical and thermal effects of this specific current, the electrical circuit between the welding wire tip and the molten pool surface is simultaneously broken, and the physical molten droplets are completely separated. This adapts to the characteristics of large-diameter aluminum alloy welding wires, which have high rigidity, are prone to mechanical vibration during the retraction process, and have molten droplets that are difficult to detach naturally due to adhesion. It avoids the problems of secondary arc length deviation and molten droplet tearing deformation caused by arbitrary speed retraction. Through the timing coordination of mechanical retraction and electrical current output, the mechanical position adjustment and electrical molten droplet separation are coordinated, ensuring that the welding wire and the molten pool can achieve a clean and complete separation state after each arc length correction. This lays the timing and process foundation for establishing a stable and reliable initial arc gap for the next welding cycle.

[0050] In a preferred embodiment of the present invention, combined with Figure 2 As shown, the servo motor is controlled to feed the wire in the reverse direction at a wire retraction speed of Ws3. Forward feeding stops during the Ts1 period. During Ts1, the welding current decreases from the peak current Ipp to the arc-maintaining current Is2, and then the reverse retraction action is initiated in the Ts2 period to retract the wire. At the end of the retraction in the Ts3 period, a droplet separation current Isr (typically ranging from 100 to 200 A, preferably 150 A) is output to completely separate the wire from the molten pool, resetting the arc length to the target value. Then, the pulse welding phase of the next cycle begins. The droplet separation current is approximately 50% of the peak current Ipp, such as 150 A, to help cleanly separate the wire from the molten pool. It is worth noting that after separation, the distance between the wire tip and the molten pool surface is the target arc length, and the initial arc length of the next welding cycle is precisely reset, achieving closed-loop constant arc length control.

[0051] In this embodiment of the invention, a control method is adopted to complete quantitative reverse retraction at a fixed preset retraction speed and to achieve dual separation by matching the output droplet separation current at the moment the retraction action is completed. This ensures that the wire retraction process is stable and uniform, and the stroke is precise and controllable. It effectively avoids the secondary deviation of arc length caused by variable speed retraction, inertial impact, and mechanical vibration. This method is suitable for the structural characteristics of large-diameter aluminum alloy welding wire, which has high rigidity, lag in deformation, and slight inertia in wire feeding. At the same time, relying on the instantaneous action of the dedicated droplet separation current, the phenomenon of droplet adhesion between the end of the welding wire and the molten pool can be completely eliminated, preventing adverse conditions such as wire sticking, short circuits, and incomplete separation. It also avoids the problem of unstable arc initiation and random arc length drift in the next welding cycle due to separation residue. Through the organic combination of mechanical displacement control and electrical current-assisted separation, the separation quality and arc length establishment accuracy after each arc length reset are improved, and the consistency and stability of arc length are maintained throughout the welding process. This effectively reduces the probability of defects such as welding spatter, arc breakage, and molten pool disturbance.

[0052] In summary, in the preferred embodiment of the present invention, combined with Figure 2 As shown, for the Ts1 interval (molten pool height detection), the welding current rapidly decreases from its peak / base value to 50A, the wire feed speed switches from 5.0 m / min to 10 m / min, and the controller starts timing; the voltage sampling module acquires the welding voltage at a frequency of 10kHz. When the voltage drops from approximately 20V to below 5V, it is determined that the welding wire has contacted the molten pool surface, timing stops, and the duration is recorded as T1 = 8ms; the relative height of the molten pool is calculated: H. pool =(10-5) m / min×0.008s = 4mm; Storage H pool The value is calculated, and the change ΔH from the previous detection value is used for subsequent parameter fine-tuning.

[0053] For the Ts2 interval (short circuit maintenance and cooling), stop wire feeding, maintain the welding current at 50A for 2ms (cooling time Tcool) to allow the molten pool to cool down appropriately, reduce heat input, and maintain the short circuit state between the welding wire and the molten pool to avoid the molten pool cooling too quickly and causing wire sticking.

[0054] For the Ts3 interval (adaptive pullback and arc length reset), based on the target arc length L arctarget =5mm, H pool =4mm, Δcomp=0.5mm, calculate the pullback displacement L retract =5+4+0.5=9.5mm; Control the servo motor to feed the wire in the reverse direction at a wire retraction speed of Ws3=10m / min, and the retraction time T retract=9.5mm / (10000 mm / min)×60=0.057s=57ms; When the retraction ends, the welding current changes to the droplet separation current Isr, which reaches 150A, to help the welding wire and the molten pool separate cleanly; After separation, the distance between the end of the welding wire and the surface of the molten pool is 5mm (target arc length), and the initial arc length of the next welding cycle is reset.

[0055] The above-mentioned constant arc length MIG welding method can be achieved through Figure 4 The welding apparatus shown includes a welding control circuit and a servo motor control module. The welding control circuit integrates a pulse welding current output module, a voltage sampling module, and a controller module. The pulse welding current output module can output peak current, base current, arc-maintaining current, and droplet separation current in stages according to the timing commands issued by the controller module, matching the current process requirements of each timing interval in the pulse welding stage and the arc detection stage. The voltage sampling module continuously collects the welding voltage of the electrode circuit in real time and transmits it back to the controller module. The controller module further combines the distance data, target arc length, and preset compensation amount to solve the wire retraction displacement, and synchronously sends wire feeding and retraction action commands to the servo motor control module. After receiving the commands, the servo motor control module drives the servo motor to pull the wire welding torch to complete all wire feeding timing actions. The servo motor pulls the wire welding torch to simultaneously carry the welding wire and electrode, and completely executes the entire process control of pulse welding.

[0056] Combination Figure 5 As shown, another embodiment of the present invention provides a constant arc length MIG welding system, comprising: The welding control unit is used to perform a pulse welding phase in each welding cycle of MIG welding, and to perform an arc detection phase after the pulse welding phase ends, until the welding cycle ends. The pulse welding subunit is used to control the welding wire to perform pulse welding according to the first wire feeding speed and in combination with preset pulse parameters for the pulse welding stage. The detection subunit is used for the arc detection stage to control the welding wire to feed towards the molten pool at a second wire feeding speed, while continuously acquiring the welding voltage, and based on the welding voltage, to obtain the distance data between the tip of the welding wire and the surface of the molten pool during the welding cycle, wherein the first wire feeding speed is less than the second wire feeding speed; based on the distance data, combined with the target arc length of the welding cycle and a preset compensation amount, to determine the retraction displacement of the welding wire; according to the retraction displacement, to control the welding wire to perform a reverse retraction action until the retraction distance of the welding wire reaches the retraction displacement, and at the end of the reverse retraction action, to perform electrical separation and physical separation between the tip of the welding wire and the surface of the molten pool.

[0057] The constant arc length MIG welding system of the present invention has the same advantages over the prior art as the aforementioned constant arc length MIG welding method, and will not be repeated here.

[0058] Another embodiment of the present invention provides an electronic device comprising: a processor and a memory, wherein the memory is used to store a computer program; When the computer program is loaded by the processor, it causes the processor to execute the constant arc length MIG welding method as described above.

[0059] The electronic device of the present invention has the same advantages over the prior art as the constant arc length MIG welding method described above, and will not be repeated here.

[0060] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A constant arc length MIG welding method, characterized in that, include: In each welding cycle of MIG welding, a pulse welding phase is performed, and after the pulse welding phase ends, an arc detection phase is performed until the welding cycle ends. Specifically, in the pulse welding stage, the welding wire is controlled to perform pulse welding according to the first wire feeding speed, combined with preset pulse parameters. For the arc detection stage, the welding wire is fed towards the molten pool at a second wire feed speed while the welding voltage is continuously collected. Based on the welding voltage, the relative height of the molten pool during the welding cycle is obtained, wherein the first wire feed speed is less than the second wire feed speed. The time taken from when the welding wire is fed at the second wire feed speed until the tip of the welding wire contacts the surface of the molten pool is obtained, and this time is used as the height detection time. The formula for calculating the relative height of the molten pool based on the first wire feed speed, the second wire feed speed, and the height detection time is: H pool =(V2 V1)×T1; where T1 is the height detection time, V1 is the first wire feeding speed, V2 is the second wire feeding speed, and H pool The relative height of the molten pool; Based on the relative height of the molten pool, combined with the target arc length of the welding cycle and the preset compensation amount, the retraction displacement of the welding wire is determined; according to the retraction displacement, the welding wire is controlled to perform a reverse retraction action until the retraction distance of the welding wire reaches the retraction displacement, and at the end of the reverse retraction action, the end of the welding wire and the surface of the molten pool are electrically and physically separated.

2. The constant arc length MIG welding method according to claim 1, characterized in that, In each welding cycle of MIG welding, a pulse welding phase is performed, and after the pulse welding phase ends, an arc detection phase is performed until the welding cycle ends, including: For the current welding cycle, first execute the preset number of pulse welding stages under the current welding cycle; After all the pulse welding stages have been completed, the arc detection stage of the current welding cycle is executed until the current welding cycle ends.

3. The constant arc length MIG welding method according to claim 1, characterized in that, The control of the welding wire according to the first wire feeding speed, combined with preset pulse parameters, includes pulse welding, including: In the pulse welding phase of each welding cycle, the peak current and base current of the welding cycle are determined according to the preset pulse parameters. The welding power supply is controlled to output according to the peak current and the base current, and the welding wire is controlled to be fed at a constant speed according to the first wire feeding speed until the pulse welding stage ends.

4. The constant arc length MIG welding method according to claim 3, characterized in that, The step of controlling the welding wire to feed towards the molten pool at a second wire feeding speed, while continuously acquiring the welding voltage, and obtaining the relative height of the molten pool during the welding cycle based on the welding voltage, includes: The welding wire is controlled to feed towards the molten pool at the second wire feeding speed, and the welding voltage is continuously collected; Based on the welding voltage, determine whether the end of the welding wire comes into contact with the surface of the molten pool; When the tip of the welding wire comes into contact with the surface of the molten pool, the feeding of the welding wire toward the molten pool is stopped; The relative height of the molten pool is determined based on the first wire feeding speed, the second wire feeding speed, and the height detection time.

5. The constant arc length MIG welding method according to claim 4, characterized in that, The step of determining whether the end of the welding wire contacts the surface of the molten pool based on the welding voltage includes: Based on the welding voltage, a comparison is made with a preset short-circuit voltage threshold to determine whether the end of the welding wire comes into contact with the surface of the molten pool. Specifically, when the welding voltage is less than the short-circuit voltage threshold, it is determined that the end of the welding wire is in contact with the surface of the molten pool; When the welding voltage is greater than or equal to the short-circuit voltage threshold, it is determined that the end of the welding wire is not in contact with the surface of the molten pool.

6. The constant arc length MIG welding method according to claim 1, characterized in that, The determination of the wire retraction displacement based on the relative height of the molten pool, combined with the target arc length of the welding cycle and a preset compensation amount, includes: The total length is obtained by adding the relative height of the molten pool, the target arc length, and the preset compensation amount. The sum of the lengths is taken as the retraction displacement of the welding wire.

7. The constant arc length MIG welding method according to claim 3, characterized in that, The step of controlling the welding wire to perform a reverse retraction action according to the retraction displacement until the retraction distance of the welding wire reaches the retraction displacement, and performing electrical and physical separation of the welding wire end from the molten pool surface at the end of the reverse retraction action, includes: The welding wire is controlled to perform a reverse retraction action at a preset retraction speed until the retraction distance of the welding wire reaches the retraction displacement; At the end of the reverse retraction action, the welding power supply is controlled to output a droplet separation current to perform electrical and physical separation between the welding wire tip and the surface of the molten pool. The droplet separation current is a preset ratio of the peak current of the welding cycle, and the amplitude of the droplet separation current is less than the peak current but greater than the base current of the welding cycle.

8. A constant arc length MIG welding system, characterized in that, include: The welding control unit is used to perform a pulse welding phase in each welding cycle of MIG welding, and to perform an arc detection phase after the pulse welding phase ends, until the welding cycle ends. The pulse welding subunit is used to control the welding wire to perform pulse welding according to the first wire feeding speed and in combination with preset pulse parameters for the pulse welding stage. The detection subunit is used for the arc detection stage to control the welding wire to feed towards the molten pool at a second wire feed speed, while continuously acquiring the welding voltage, and based on the welding voltage, to obtain the relative height of the molten pool during the welding cycle, wherein the first wire feed speed is less than the second wire feed speed; to obtain the time elapsed between the welding wire feeding at the second wire feed speed and the contact between the tip of the welding wire and the surface of the molten pool, and to use the elapsed time as the height detection time; wherein the formula for calculating the relative height of the molten pool based on the first wire feed speed, the second wire feed speed, and the height detection time is: H pool =(V2 V1)×T1; where T1 is the height detection time, V1 is the first wire feeding speed, V2 is the second wire feeding speed, and H pool The relative height of the molten pool; Based on the relative height of the molten pool, combined with the target arc length of the welding cycle and the preset compensation amount, the retraction displacement of the welding wire is determined; according to the retraction displacement, the welding wire is controlled to perform a reverse retraction action until the retraction distance of the welding wire reaches the retraction displacement, and at the end of the reverse retraction action, the end of the welding wire and the surface of the molten pool are electrically and physically separated.

9. An electronic device, characterized in that, include: Processor and memory, the memory being used to store computer programs; When the computer program is loaded by the processor, it causes the processor to execute the constant arc length MIG welding method as described in any one of claims 1-7.

Images