A method, system, device and medium for controlling MIG welding of a sheet metal

Abstract

The application provides a kind of thick and thin plate MIG welding control method, system, equipment and medium, it is related to gas shielded welding technical field, the method comprises: the phase signal of welding torch in swing cycle is acquired in real time;According to the phase signal, whether the pointing position of welding torch reaches the limit position of thick plate side or the limit position of thin plate side is judged;When the pointing position reaches the limit position of thick plate side or the limit position of thin plate side, according to the limit position of thick plate side or the limit position of thin plate side corresponding pulse current and arc voltage, welding parameter is generated;Based on welding parameter, control welding power supply output, simultaneously according to the arc morphology corresponding to the limit position of thick plate side or the limit position of thin plate side, arc is regulated;Wherein, the pulse current corresponding to the limit position of thick plate side is greater than the pulse current corresponding to the limit position of thin plate side.The application improves the welding quality for the butt joint of thin plate and thick plate.

Description

Technical Field

[0001] This invention relates to the field of gas shielded welding technology, and more specifically, to a method, system, equipment, and medium for controlling MIG welding of thick and thin plates. Background Technology

[0002] MIG welding of aluminum alloys offers advantages such as high welding efficiency, ease of automation, and automatic removal of oxide films from workpiece surfaces, making it widely used in new energy vehicles, aerospace, and rail transportation. The industry commonly uses 1.6mm diameter aluminum welding wire, which offers deep penetration, fast welding speed, and low heat input, making it suitable for high-efficiency production needs.

[0003] In related technologies, during butt joint welding of thin and thick plates, the thick plate requires sufficient heat input to ensure penetration and joint strength, while the thin plate requires strict control of heat input; otherwise, defects such as burn-through, undercut, and other defects are easily produced. Although 1.6mm aluminum welding wire has excellent performance, its high rigidity and significant fluctuations in wire feeding resistance lead to poor arc stability and difficulty in precisely controlling heat input. This makes it difficult to simultaneously meet the dual requirements of large penetration for thick plates and low heat input for thin plates, easily resulting in insufficient penetration for thick plates or burn-through and undercut for thin plates, seriously affecting welding quality and production yield. Summary of the Invention

[0004] The problem addressed by this invention is how to improve the welding quality of butt joints between thin and thick plates.

[0005] To address the above problems, this invention provides a method, system, equipment, and medium for controlling MIG welding of thick and thin plates.

[0006] In a first aspect, the present invention provides a method for controlling MIG welding of thick and thin plates, comprising: When the welding torch oscillates along the welding direction in the butt joint area composed of thick and thin plates according to a preset oscillation cycle, the phase signal of the welding torch within the oscillation cycle is acquired in real time. Based on the phase signal, determine whether the pointing position of the welding torch has reached the limit position on the thick plate side or the limit position on the thin plate side. When the pointing position reaches the limit position of the thick plate side or the limit position of the thin plate side, welding parameters are generated according to the pulse current and arc voltage corresponding to the limit position of the thick plate side or the limit position of the thin plate side. Based on the welding parameters, the welding power output is controlled, and the arc is adjusted according to the arc shape corresponding to the extreme position on the thick plate side or the extreme position on the thin plate side. The pulse current corresponding to the extreme position on the thick plate side is greater than the pulse current corresponding to the extreme position on the thin plate side.

[0007] Optionally, determining whether the pointing position of the welding torch has reached the limit position on the thick plate side or the limit position on the thin plate side based on the phase signal includes: Based on the phase signal, the phase interval in which the welding torch is located during the oscillation cycle is determined; When the phase interval is the phase region on the thick plate side, it is determined that the pointing position has reached the limit position on the thick plate side; When the phase interval is the phase region on the thin plate side, it is determined that the pointing position has reached the limit position on the thin plate side.

[0008] Optionally, when the pointing position reaches the limit position on the thick plate side or the limit position on the thin plate side, welding parameters are generated based on the pulse current and arc voltage corresponding to the limit position on the thick plate side or the limit position on the thin plate side, including: In response to the pointing position reaching the limit position on the thick plate side or the limit position on the thin plate side, the arc pattern corresponding to the limit position on the thick plate side or the limit position on the thin plate side is determined. Based on the arc morphology, determine the arc voltage corresponding to the extreme position on the thick plate side or the extreme position on the thin plate side; The welding parameters are generated based on the pulse current and the arc voltage corresponding to the extreme positions on the thick plate side or the thin plate side.

[0009] Optionally, the arc pattern corresponding to the extreme position on the thick plate side is a preset short arc pattern, and the arc pattern corresponding to the extreme position on the thin plate side is a preset long arc pattern.

[0010] Optionally, the step of controlling the welding power output based on the welding parameters, and simultaneously adjusting the arc according to the arc pattern corresponding to the extreme position on the thick plate side or the extreme position on the thin plate side, includes: Based on the welding parameters, the welding power supply is controlled to output a corresponding pulse current waveform; Within each pulse cycle of the pulse current waveform output by the welding power source, the length of the arc is stabilized within the length range corresponding to the arc shape by short-circuit retraction constant arc length control.

[0011] Optionally, the short-circuit retraction constant arc length control operation specifically includes: For each pulse cycle, the molten droplets are detected in real time; When the necking detection signal of the molten droplet is obtained, the molten droplet is controlled to contact the molten pool according to the preset current adjustment rule, and the molten droplet is cooled for a preset cooling time when it contacts the molten pool. After the cooling process is completed, the length of the electric arc is adjusted according to the length range corresponding to the arc shape by means of a preset retraction operation and a preset thrust current application operation.

[0012] Optionally, the welding torch uses welding wire with a diameter of 1.6 mm for welding.

[0013] In a second aspect, the present invention provides a thick and thin plate MIG welding control system, comprising: The signal acquisition unit is used to acquire the phase signal of the welding torch in real time during the oscillation period when the welding torch oscillates along the welding direction in the butt joint area composed of thick and thin plates according to a preset oscillation period. The judgment unit is used to determine, based on the phase signal, whether the pointing position of the welding gun has reached the limit position on the thick plate side or the limit position on the thin plate side. The parameter generation unit is used to generate welding parameters based on the pulse current and arc voltage corresponding to the extreme position of the thick plate side or the extreme position of the thin plate side when the pointing position reaches the extreme position of the thick plate side or the extreme position of the thin plate side. The control unit is used to control the output of the welding power source based on the welding parameters, and to adjust the arc according to the arc shape corresponding to the extreme position on the thick plate side or the extreme position on the thin plate side. The pulse current corresponding to the extreme position on the thick plate side is greater than the pulse current corresponding to the extreme position on the thin plate side.

[0014] 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 above-mentioned MIG welding control method for thick and thin plates.

[0015] Fourthly, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the above-described thick and thin plate MIG welding control method is implemented.

[0016] The present invention relates to a method, system, equipment, and medium for controlling MIG welding of thick and thin plates. By periodically oscillating the welding torch in the butt joint area of ​​the thick and thin plates according to a preset oscillation cycle and acquiring phase signals in real time, the dynamic spatial position information of the welding torch can be accurately captured. This provides a timing and position reference for subsequent zoned control, allowing the welding process to dynamically match different welding strategies according to the welding torch position, solving the problems of disconnect between welding position and parameters and uneven heat input distribution in traditional welding methods. Based on the phase signal, it determines whether the welding torch has reached the limit position on the thick or thin plate side, discretizing the continuous oscillation process into two key action zones for the thick and thin plates. This achieves precise correspondence between spatial position and welding area, avoiding energy mismatch of the arc in the transition zone. After reaching the limit position, welding parameters are generated according to the corresponding pulse current and arc voltage, and differentiated according to the different heat input requirements of the thick and thin plates. A large current parameter is matched on the thick plate side to ensure penetration depth, while a small current parameter is matched on the thin plate side to control heat input, fundamentally solving the contradiction in heat input requirements between thick and thin plates and achieving on-demand energy distribution. Based on the generated parameters, the power output is controlled and the arc is adjusted according to the corresponding arc shape, so that a concentrated short arc is formed on the thick plate side and a dispersed long arc is formed on the thin plate side, which further enhances the heat input zoning effect. The short arc improves the penetration capability of the thick plate, and the long arc reduces the risk of overheating of the thin plate. Ultimately, it takes into account both the penetration of the thick plate and the prevention of burn-through of the thin plate, and improves the stability of welding quality. Attached Figure Description

[0017] Figure 1 This is a schematic flowchart of the MIG welding control method for thick and thin plates according to an embodiment of the present invention; Figure 2 This is a timing diagram of the coordinated control of welding torch oscillation phase and welding conditions according to an embodiment of the present invention; Figure 3 This is one of the corresponding diagrams of electrical characteristics and droplet transition morphology in an embodiment of the present invention; Figure 4 This is the second diagram showing the correspondence between the electrical characteristics and the droplet transition morphology of an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of a thick and thin plate MIG welding control 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 in the figure, an embodiment of the present invention provides a method for controlling MIG welding of thick and thin plates, comprising: When the welding torch oscillates along the welding direction in the butt joint area composed of thick and thin plates according to a preset oscillation cycle, the phase signal of the welding torch within the oscillation cycle is acquired in real time.

[0023] Specifically, the welding torch is driven by a welding robot and oscillates periodically along the welding direction. In a preferred embodiment of the invention, the periodic oscillation is preferably a sinusoidal oscillation. Based on this, a position signal corresponding to the spatial position of the welding torch is generated in real time; this signal is the phase signal. This process converts the mechanical oscillation motion (spatial and temporal characteristics) of the welding torch into an electrical signal that can be read in real time, providing a timing and position reference for subsequent coordinated control of the oscillation phase and welding conditions.

[0024] Based on the phase signal, determine whether the pointing position of the welding torch has reached the limit position on the thick plate side or the limit position on the thin plate side.

[0025] Specifically, based on the acquired phase signal, a mapping relationship between the phase signal and the spatial pointing position of the welding torch is established. By analyzing and identifying the phase signal, the position identification of the end point of the welding torch swing stroke is completed, realizing the logical conversion from temporal phase information to spatial position state, and defining the working boundary position of the welding torch corresponding to the thick plate side and the thin plate side respectively.

[0026] When the pointing position reaches the limit position of the thick plate side or the limit position of the thin plate side, welding parameters are generated according to the pulse current and arc voltage corresponding to the limit position of the thick plate side or the limit position of the thin plate side.

[0027] Specifically, the welding torch's extreme position identification result serves as the trigger condition, invoking a preset combination of differentiated welding parameters. For thick plates, welding parameters containing a large pulse current (e.g., 160-280A) and a lower arc voltage (e.g., 22-25V, for forming a short arc) are invoked. For thin plates, welding parameters containing a small pulse current (e.g., 80-150A) and a higher arc voltage (e.g., 21-23V, for forming a long arc) are invoked. These two sets of welding parameters together constitute the specific instruction set for achieving differentiated heat input control of long and short arcs.

[0028] Based on the welding parameters, the welding power output is controlled, and the arc is adjusted according to the arc shape corresponding to the extreme position on the thick plate side or the extreme position on the thin plate side; wherein, the pulse current corresponding to the extreme position on the thick plate side is greater than the pulse current corresponding to the extreme position on the thin plate side.

[0029] Specifically, the welding power source outputs a corresponding pulse current waveform based on the received welding parameter set. Simultaneously, to ensure the stable maintenance of the short and long arc configurations, especially when using 1.6mm aluminum welding wire, this embodiment of the invention employs short-circuit retraction constant arc length control throughout the entire welding process. Within each pulse cycle, the arc is periodically and precisely reset through a cyclical operation of active wire feeding short-circuiting, maintaining cooling, wire retraction, and applying a thrust current. Specifically, at the extreme positions on the thick plate side, this control stabilizes the arc in a short arc state to achieve a large penetration depth; at the extreme positions on the thin plate side, it stabilizes it in a long arc state to achieve low heat input, thereby ultimately achieving the synergistic control objective of achieving the penetration depth target on the thick plate side and preventing burn-through on the thin plate side. It is worth mentioning that, in a preferred embodiment of the invention, the ratio of the pulse current corresponding to the extreme positions on the thick plate side to the pulse current corresponding to the extreme positions on the thin plate side is greater than or equal to 2.

[0030] The MIG welding control method for thick and thin plates of this invention uses a welding torch to periodically oscillate in the butt joint area of ​​thick and thin plates according to a preset oscillation cycle and acquires phase signals in real time. This accurately captures the dynamic spatial position information of the welding torch, providing a timing and position reference for subsequent zoned control. The welding process can dynamically match different welding strategies according to the welding torch position, solving the problems of disconnect between welding position and parameters and uneven heat input distribution in traditional welding methods. Based on the phase signal, it determines whether the welding torch has reached the limit position on the thick or thin plate side, discretizing the continuous oscillation process into two key action zones for thick and thin plates. This achieves precise correspondence between spatial position and welding area, avoiding energy mismatch of the arc in the transition zone. After reaching the limit position, welding parameters are generated according to the corresponding pulse current and arc voltage. Differential adaptations are made for the different heat input requirements of thick and thin plates: a large current parameter is matched on the thick plate side to ensure penetration depth, and a small current parameter is matched on the thin plate side to control heat input. This fundamentally solves the contradiction in heat input requirements between thick and thin plates, achieving on-demand energy distribution. Based on the generated parameters, the power output is controlled and the arc is adjusted according to the corresponding arc shape, so that a concentrated short arc is formed on the thick plate side and a dispersed long arc is formed on the thin plate side, which further enhances the heat input zoning effect. The short arc improves the penetration capability of the thick plate, and the long arc reduces the risk of overheating of the thin plate. Ultimately, it takes into account both the penetration of the thick plate and the prevention of burn-through of the thin plate, and improves the stability of welding quality.

[0031] Optionally, determining whether the pointing position of the welding torch has reached the limit position on the thick plate side or the limit position on the thin plate side based on the phase signal includes: Based on the phase signal, the phase interval in which the welding torch is located during the oscillation cycle is determined; When the phase interval is the phase region on the thick plate side, it is determined that the pointing position has reached the limit position on the thick plate side; When the phase interval is the phase region on the thin plate side, it is determined that the pointing position has reached the limit position on the thin plate side.

[0032] Specifically, during the periodic oscillation of the welding torch along the joint area of ​​thick and thin plates, the mechanical oscillation stroke of the welding torch has a fixed corresponding relationship with the timing phase. The phase signal acquired in real time can completely characterize the timing operation state of the welding torch within a single oscillation cycle. Specifically, the real-time acquired phase signal is first analyzed. Based on the pre-divided and calibrated phase interval scale, the specific phase interval in which the welding torch is located within the current oscillation cycle is determined. Using the pre-established mapping relationship between the phase interval and the spatial pointing position of the welding torch, the phase signal characterizing the timing features is transformed into a recognizable spatial position determination criterion. When the analyzed phase interval falls within the preset thick plate side phase area calibration range, it can be logically determined that the pointing position of the current oscillation endpoint of the welding torch has reached the thick plate side limit position. When the analyzed phase interval falls within the preset thin plate side phase area calibration range, it is simultaneously determined that the pointing position of the current oscillation endpoint of the welding torch has reached the thin plate side limit position. This achieves non-contact real-time identification of the spatial limit position of the welding torch based on the timing features of the phase signal. Figure 2 As shown, in a preferred embodiment of the present invention, when the phase signal indicates that the welding torch is at the extreme position near the thick plate side, it enters the first phase P1, at which time the corresponding arc voltage and pulse current can be called, i.e., the welding conditions on the thick plate side; when the signal indicates that the welding torch is at the extreme position near the thin plate side, it enters the second phase P2, at which time the corresponding arc voltage and pulse current can be called, i.e., the welding conditions on the thin plate side.

[0033] In this embodiment of the invention, by dividing the welding torch oscillation period into different phase intervals and relying on the phase signal to complete the phase interval identification and thus realize the determination of the extreme position, the coupling and matching of the welding torch oscillation timing characteristics and spatial position state can be realized. This simplifies the detection and determination logic of the welding torch position during the butt welding of thick and thin plates. It can reliably identify the extreme positions on both sides without relying on additional hardware detection devices, ensuring the synchronization and real-time performance of parameter switching and arc control during the butt welding of thick and thin plates, and effectively avoiding the problem of welding parameter matching disorder caused by position determination lag or determination deviation.

[0034] Optionally, when the pointing position reaches the limit position on the thick plate side or the limit position on the thin plate side, welding parameters are generated based on the pulse current and arc voltage corresponding to the limit position on the thick plate side or the limit position on the thin plate side, including: In response to the pointing position reaching the limit position on the thick plate side or the limit position on the thin plate side, the arc pattern corresponding to the limit position on the thick plate side or the limit position on the thin plate side is determined. Based on the arc morphology, determine the arc voltage corresponding to the extreme position on the thick plate side or the extreme position on the thin plate side; The welding parameters are generated based on the pulse current and the arc voltage corresponding to the extreme positions on the thick plate side or the thin plate side.

[0035] Specifically, firstly, after detecting that the welding torch has reached the corresponding limit position, based on the welding conditions and heat input requirements of thick and thin plates respectively, a preset arc mode is matched. Utilizing the inherent physical characteristics of different arc modes in arc length maintenance, heat distribution, and droplet transfer, the rated arc voltage parameters that can maintain stable and self-sustaining combustion of the arc mode are solved through reverse matching. Then, the pre-set pulse current parameters matching the working conditions of the thick and thin plates are coupled, adapted, and regularized with the arc voltage parameters determined by the arc mode matching. The parameters are then structured and arranged according to the process parameter configuration logic of pulsed MIG welding, forming a... Standardized welding parameters directly drive the operation of the welding power source, thereby establishing a correlation and mapping relationship between spatial position, arc physical form, and electrical operating parameters. This fully adapts to the differentiated needs of welding butt joints of aluminum alloy thick and thin plates, where thick plates require sufficient heat input to ensure penetration depth, while thin plates require limited heat input to avoid forming defects. At the same time, it takes into account the material characteristics of large-diameter aluminum welding wire, which has high rigidity and is prone to arc condition deviation due to fluctuations in wire feeding resistance. Through hierarchical parameter matching logic, it realizes the directional configuration and automatic generation of process parameters for different welding areas, establishing a complete parameter supply chain for subsequent precise output of the welding power source and controllable adjustment of the arc form.

[0036] In a preferred embodiment of the present invention, the relationship between the pulse current and arc voltage on the thick plate side and the melt depth on the thick plate side is as follows: D thick = k thick ×(I big ×U short / v welding ); Among them, D thick k represents the target melt depth on the thicker side. thick For thick plates, I is the material coefficient (approximately 0.01-0.015). big U is the pulse current corresponding to the extreme position on the thick plate side. short To preset the arc voltage corresponding to the short arc mode, v welding The welding speed is (mm / s).

[0037] The relationship between the pulse current and arc voltage on the thin plate side and the heat input on the thin plate side is as follows: Q thin = (I small ×U long ) / v welding ≤ Q max ; Among them, Q maxThe maximum permissible heat input (J / mm) for a thin sheet without burn-through is given. For a 3mm thick 6063 aluminum alloy, Q is recommended. max ≤ 180 J / mm, Q thin I represents the heat input of the thin plate under the corresponding pulse current and arc voltage. small U is the pulse current corresponding to the extreme position on the thin plate side. long To preset the arc voltage corresponding to the long arc shape, v welding The welding speed is (mm / s).

[0038] In this embodiment of the invention, welding parameters are generated by selecting the arc shape, matching the arc voltage, and combining the pulse current and arc voltage using a position-triggered linkage. The process parameters are configured differently according to the actual working conditions of different welding areas of thick and thin plates. This allows for a suitable matching relationship between the arc shape, arc voltage, and pulse current, effectively adapting to the different heat input requirements of butt welding of thick and thin plates and the arc operation fluctuations caused by the material properties of the aluminum welding wire itself. This avoids the problems of poor working condition adaptability, arc combustion instability, and unbalanced heat input distribution caused by using uniform welding parameters. The welding parameters are dynamically and adaptively generated according to the position of the welding torch and the welding area, thereby ensuring the continuity of the process logic and the adaptability of the working conditions in the butt welding process of thick and thin plates.

[0039] Optionally, the arc pattern corresponding to the extreme position on the thick plate side is a preset short arc pattern, and the arc pattern corresponding to the extreme position on the thin plate side is a preset long arc pattern.

[0040] Specifically, when the welding torch swings to the extreme position on the thick plate side, a short arc shape is forcibly formed and maintained. This short arc shape is characterized by a relatively low arc voltage, short arc length, concentrated shape, and high rigidity. The short arc shape can highly concentrate the welding energy (provided by the simultaneously applied large pulse current) and penetrate deeply into the thick plate base material, effectively overcoming the rapid heat dissipation characteristic of aluminum alloys. This is the physical guarantee for obtaining a stable and sufficient penetration depth (e.g., ≥3mm). Conversely, when the welding torch swings to the extreme position on the thin plate side, a long arc shape is forcibly formed and maintained. This long arc shape is characterized by a relatively high arc voltage, longer arc length, and more dispersed shape. Combined with a smaller pulse current, this creates welding conditions with low heat input density and a relatively dispersed heating area.

[0041] In this embodiment of the invention, by pre-setting fixed short and long arc patterns for the extreme positions of the thick plate and the thin plate respectively, the arc combustion mode is differentiated according to the welding characteristics of the thick and thin plates, so that the heat distribution characteristics of different welding areas are adapted to the workpiece forming requirements. This effectively balances the process contradictions caused by insufficient penetration of the thick plate and overheating defects of the thin plate. At the same time, it provides a unified and fixed morphological reference standard for arc voltage setting, pulse current configuration and constant arc length control, reducing the probability of random arc pattern drift and disordered switching of working conditions during the welding process, and improving the stability, controllability and adaptability of the overall welding process.

[0042] Optionally, the step of controlling the welding power output based on the welding parameters, and simultaneously adjusting the arc according to the arc pattern corresponding to the extreme position on the thick plate side or the extreme position on the thin plate side, includes: Based on the welding parameters, the welding power supply is controlled to output a corresponding pulse current waveform; Within each pulse cycle of the pulse current waveform output by the welding power source, the length of the arc is stabilized within the length range corresponding to the arc shape by short-circuit retraction constant arc length control.

[0043] Specifically, firstly, welding parameters are converted into output commands for the welding power supply, controlling the power supply to generate pulsed current waveforms that match the heat demand of the thick or thin plate side, thereby achieving preliminary zoning of welding heat input at the energy level. However, relying solely on static parameter output is insufficient to address the spontaneous arc length drift caused by factors such as wire feeding fluctuations and droplet transfer during actual welding, especially when using rigid 1.6mm aluminum welding wire. This drift directly disrupts the preset short or long arc shape, leading to uncontrolled heat input. Therefore, this invention further employs short-circuit retraction constant arc length control synchronously within each pulsed current waveform cycle, periodically resetting and stabilizing the arc length within the range corresponding to the required short or long arc shape for the current phase (thick or thin plate side). This ensures that the preset arc physical shape (concentrated penetration of the short arc or dispersed heating of the long arc) can be reliably maintained throughout the welding process, especially in the thick-thin plate interface area where parameters frequently switch.

[0044] Combination Figure 3The diagram illustrates the control of a long arc pulse, showing the dynamic evolution of arc voltage U and welding current I within a single pulse cycle under short-circuit retraction constant arc length control. Specifically, node 1 corresponds to the initial steady state of droplet formation at the welding wire tip; node 2, after detecting the droplet necking signal, the current rises rapidly while the voltage remains high, and the corresponding physical image shows that the concentrated arc heating causes the droplet to grow and neck; node 3 marks the formation of a short-circuit bridge when the droplet contacts the molten pool, at which point the current reaches its peak and then drops sharply, and the voltage subsequently drops drastically to near zero, with a bright short-circuit flash visible in the physical image; node 4, during the cooling and retraction period, the current drops to a lower arc-maintaining level, the control system drives the welding wire to rapidly reverse and retract, the voltage remains low, and the physical image shows the droplet being pulled off by mechanical force, extinguishing the arc; node 5, after the retraction ends and the thrust current is reapplied, the arc is forcibly reignited, and the voltage and current rapidly rise to the steady-state operating level, with the arc re-established visible in the physical image.

[0045] Combination Figure 4 The diagram shows a control schematic for short arc pulses, illustrating the dynamic evolution waveforms of arc voltage U and welding current I within a single pulse cycle under short-circuit retraction constant arc length control. Specifically, node 1 corresponds to the stage where the welding wire tip is in steady-state combustion and the initial formation of the molten droplet; node 2, after the molten droplet necking is detected, the current rapidly rises to its peak value and the voltage remains high, corresponding to the physical process in the physical image where the concentrated heating of the arc causes the molten droplet to grow significantly and form a clear necking; node 3 reflects the formation of a short-circuit bridge when the molten droplet contacts the molten pool under the action of gravity and electromagnetic force. At this time, the current reaches its maximum value and then drops sharply, and the voltage drops sharply to near zero. A strong short-circuit flash can be seen in the physical image; node 4 is the cooling and retraction period. The current drops to a lower arc-maintaining level, and the control system drives the welding wire to quickly reverse and retract. The voltage remains low, and the physical image shows that the molten droplet is forcibly pulled off and falls off under the action of mechanical force and surface tension; node 5 corresponds to the end of the retraction and the reapplication of the thrust current. The arc is instantly re-ignited, and the voltage and current quickly return to the steady-state operating range. A bright shape of the re-established arc can be seen in the physical image.

[0046] In this embodiment of the invention, by combining the macroscopic welding waveform output with the microscopic short-circuit retraction constant arc length control within each pulse cycle, the physical state of the arc is controlled. This avoids the problem of spontaneous arc elongation or shortening caused by wire characteristics, wire feed fluctuations, or the randomness of droplet transfer in traditional methods, ensuring the constant stability of the preset short and long arc configurations throughout the welding process, especially under conditions of repeated switching between thick and thin plate sides.

[0047] Optionally, the short-circuit retraction constant arc length control operation specifically includes: For each pulse cycle, the molten droplets are detected in real time; When the necking detection signal of the molten droplet is obtained, the molten droplet is controlled to contact the molten pool according to the preset current adjustment rule, and the molten droplet is cooled for a preset cooling time when it contacts the molten pool. After the cooling process is completed, the length of the electric arc is adjusted according to the length range corresponding to the arc shape by means of a preset retraction operation and a preset thrust current application operation.

[0048] Specifically, the short-circuit retraction constant arc length control operation does not rely on the passive self-adjustment of the arc, but actively intervenes in a closed loop within each pulse cycle to solve the problem of arc length drift caused by the high rigidity and fluctuating wire feeding resistance of 1.6mm aluminum welding wire. First, taking one pulse cycle as a unit, it begins with real-time detection of the critical state at the end of the droplet transition, i.e., necking. In this embodiment, the necking detection signal can be the arc voltage characteristic change signal. By monitoring the arc voltage in real time and setting an appropriate threshold or waveform recognition algorithm, the voltage mutation signal representing the occurrence of necking can be captured. The necking detection signal can also be the welding current change rate signal. By detecting the differential signal of the current, the inflection point of the rapid current decrease can be captured, which usually corresponds to the occurrence of necking. Once a necking detection signal is acquired, the first stage of active intervention is triggered. Based on a preset current adjustment rule (rapidly reducing the welding current to a low arc-maintaining current or zero), the welding wire is simultaneously accelerated forward. The purpose is not to wait for the molten droplet to transition naturally, but to actively drive the droplet to contact the molten pool, thereby creating a controllable, instantaneous short-circuit state. During short-circuit formation, this short-circuit state needs to be maintained for a preset cooling time, creating a brief heat input window and significantly reducing the average heat input within the pulse cycle. On the thick plate side, the cooling time can be set shorter to ensure molten pool activity; on the thin plate side, the cooling time should be set longer to minimize heat input. After cooling, according to a preset retraction operation rule, the welding wire is rapidly retracted in the reverse direction at a speed much higher than the wire feed speed, and simultaneously, a droplet thrust current is output according to a preset thrust current application rule. The mechanical action of the retraction combined with the electrodynamic action of the thrust current forces the molten droplet to detach from the welding wire tip, precisely re-igniting the arc in the process. By coordinating the distance, speed, and thrust current of the retraction, the initial length of the arc after reignition can be directly determined, thus achieving a periodic, open-loop reset of the arc length.

[0049] In a preferred embodiment of the present invention, if the welding current is rapidly reduced to a lower arc-maintaining current, the arc-maintaining current is typically 20%-50% of the peak current (approximately 60-150A); the cooling time is typically 0.5-2.5ms; and the reverse retraction speed of the welding wire is typically 2-5 times the forward wire feeding speed.

[0050] In another preferred embodiment of the invention, taking one pulse cycle of the thick plate side (short arc configuration) as an example, the welding power supply outputs a pulse with a peak current of 260A. During this period, the formation state of the molten droplet is detected in real time by monitoring the arc voltage signal or the welding current change rate signal. When a necking characteristic signal of droplet neck thinning is detected, firstly, the output current is abruptly reduced from the peak value of 260A to a thrust current level of 120A within 0.1ms; simultaneously, a command is issued to the wire feeder to instantly accelerate from the current wire feed speed of 8m / min to a higher wire feed speed, pushing the molten droplet to quickly descend and form a stable short-circuit bridge with the molten pool, at which point the arc voltage drops to almost zero. After the short circuit is formed, this state is maintained for a cooling time of 1.0ms, during which the current remains low and the heat input is extremely low. After 1.0ms, the wire feeder immediately reverses, retracting the welding wire at a high speed of 15m / min, while the current output by the welding power supply is maintained at a thrust current level of 120A. Under the combined action of wire retraction and thrust current, the short-circuit liquid bridge is broken, the molten droplet falls into the molten pool, and a new arc is re-established between the wire tip and the molten pool. By setting the retraction displacement to 0.5mm, the newly ignited arc length is precisely reset to a shorter value, matching the preset 20V low arc voltage (short arc). On the thin plate side, the process is similar, but the parameters are different. After necking is detected, the current may drop to 70A, the cooling time is extended to 2.0ms, the retraction speed is set to 10m / min, and finally the arc length is reset to a longer value to match the 24V arc voltage (long arc).

[0051] Optionally, the welding torch uses welding wire with a diameter of 1.6 mm for welding.

[0052] Specifically, although 1.6mm aluminum welding wire has the advantages of fast welding speed, deep penetration, and relatively low heat input, its high rigidity and fluctuating wire feeding resistance lead to arc instability in traditional methods. Therefore, by limiting the use of 1.6mm diameter welding wire as the welding consumable and simultaneously calibrating the numerical range of the oscillation frequency and amplitude during the welding torch oscillation process, it is possible to fully utilize the inherent process advantages of this specification of welding wire, such as high welding efficiency, excellent penetration performance, and controllable overall heat input. By relying on the oscillation frequency and amplitude within a reasonable range to constrain the reciprocating motion trajectory and rhythm of the welding torch, the oscillation stroke of the welding torch in the butt joint area of ​​thick and thin plates is precisely matched with the bevel width and heat-affected zone of the plate. This avoids excessive oscillation frequency causing mechanical vibration that exacerbates wire feeding disturbance, while preventing excessive oscillation amplitude from causing the arc to deviate from the center of the butt weld pool or insufficient amplitude from covering the welding areas of the plates on both sides. This mitigates the drawbacks of the 1.6mm welding wire itself, such as high rigidity and random fluctuations in resistance during wire feeding, which lead to arc length drift, disordered droplet transfer, and unstable combustion state.

[0053] In addition, the preset oscillation cycle corresponds to an oscillation frequency of 2.0–3.5Hz; the oscillation amplitude of the welding torch is 1–3mm, the oscillation amplitude needs to cover the weld seam and be slightly biased towards the thick plate side; the dwell time at the extreme positions on both sides is 0.05–0.10s, and fusion is ensured by setting a certain dwell time.

[0054] The oscillation frequency is set according to the welding speed. Specifically, the oscillation frequency needs to be matched with the welding speed, and its expression is: f swing = v welding / Δx; Among them, v welding Here, Δx represents the welding speed (mm / s), and Δx is the distance the welding torch travels in one oscillation cycle. Typically, Δx = 3-6 mm. swing The oscillation frequency is (Hz, Hertz, cycles / second).

[0055] In this embodiment of the invention, by limiting the aluminum welding wire of a fixed specification and matching the welding torch oscillation frequency and oscillation amplitude within a preferred range, the advantages of high-efficiency welding and excellent penetration performance of large-diameter aluminum welding wire can be retained, while effectively offsetting the potential for arc instability caused by the rigidity of the welding wire itself and the fluctuation of wire feeding resistance. This makes the welding torch oscillation motion state highly compatible with the welding conditions of butt welding of thick and thin plates, ensuring the stability of phase signal acquisition and the accuracy of position determination, and improving the process adaptability, operational stability and weld formation consistency of the butt welding process of thick and thin plates.

[0056] Combination Figure 5 As shown, another embodiment of the present invention provides a thick and thin plate MIG welding control system, comprising: The signal acquisition unit is used to acquire the phase signal of the welding torch in real time during the oscillation period when the welding torch oscillates along the welding direction in the butt joint area composed of thick and thin plates according to a preset oscillation period. The judgment unit is used to determine, based on the phase signal, whether the pointing position of the welding gun has reached the limit position on the thick plate side or the limit position on the thin plate side. The parameter generation unit is used to generate welding parameters based on the pulse current and arc voltage corresponding to the extreme position of the thick plate side or the extreme position of the thin plate side when the pointing position reaches the extreme position of the thick plate side or the extreme position of the thin plate side. The control unit is used to control the output of the welding power source based on the welding parameters, and to adjust the arc according to the arc shape corresponding to the extreme position on the thick plate side or the extreme position on the thin plate side. The pulse current corresponding to the extreme position on the thick plate side is greater than the pulse current corresponding to the extreme position on the thin plate side.

[0057] The thick and thin plate MIG welding control system of the present invention has the same advantages over the prior art as the aforementioned thick and thin plate MIG welding control 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 thick and thin plate MIG welding control method as described above.

[0059] The electronic device of the present invention has the same advantages over the prior art as the aforementioned thick and thin plate MIG welding control method over the prior art, and will not be repeated here.

[0060] Another embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, it implements the above-described thick and thin plate MIG welding control method.

[0061] The computer-readable storage medium of the present invention has the same advantages over the prior art as the aforementioned thick and thin plate MIG welding control method over the prior art, and will not be repeated here.

[0062] 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 method for controlling MIG welding of thick and thin plates, characterized in that, include: When the welding torch oscillates along the welding direction in the butt joint area composed of thick and thin plates according to a preset oscillation cycle, the phase signal of the welding torch within the oscillation cycle is acquired in real time. Based on the phase signal, determine whether the pointing position of the welding torch has reached the limit position on the thick plate side or the limit position on the thin plate side. When the pointing position reaches the limit position of the thick plate side or the limit position of the thin plate side, welding parameters are generated according to the pulse current and arc voltage corresponding to the limit position of the thick plate side or the limit position of the thin plate side. Based on the welding parameters, the output of the welding power supply is controlled, and the arc is adjusted according to the arc shape corresponding to the extreme position on the thick plate side or the extreme position on the thin plate side. The pulse current corresponding to the extreme position on the thick plate side is greater than the pulse current corresponding to the extreme position on the thin plate side.

2. The method for controlling MIG welding of thick and thin plates according to claim 1, characterized in that, The step of determining whether the pointing position of the welding torch has reached the limit position on the thick plate side or the limit position on the thin plate side based on the phase signal includes: Based on the phase signal, the phase interval in which the welding torch is located during the oscillation cycle is determined; When the phase interval is the phase region on the thick plate side, it is determined that the pointing position has reached the limit position on the thick plate side; When the phase interval is the phase region on the thin plate side, it is determined that the pointing position has reached the limit position on the thin plate side.

3. The method for controlling MIG welding of thick and thin plates according to claim 1, characterized in that, When the pointing position reaches the limit position on the thick plate side or the limit position on the thin plate side, welding parameters are generated according to the pulse current and arc voltage corresponding to the limit position on the thick plate side or the limit position on the thin plate side, including: In response to the pointing position reaching the limit position on the thick plate side or the limit position on the thin plate side, the arc pattern corresponding to the limit position on the thick plate side or the limit position on the thin plate side is determined. Based on the arc morphology, determine the arc voltage corresponding to the extreme position on the thick plate side or the extreme position on the thin plate side; The welding parameters are generated based on the pulse current and the arc voltage corresponding to the extreme positions on the thick plate side or the thin plate side.

4. The method for controlling MIG welding of thick and thin plates according to claim 1, characterized in that, The arc pattern corresponding to the extreme position on the thick plate side is a preset short arc pattern, and the arc pattern corresponding to the extreme position on the thin plate side is a preset long arc pattern.

5. The method for controlling MIG welding of thick and thin plates according to claim 1, characterized in that, The step of controlling the welding power output based on the welding parameters, and simultaneously adjusting the arc according to the arc pattern corresponding to the extreme position on the thick plate side or the extreme position on the thin plate side, includes: Based on the welding parameters, the welding power supply is controlled to output a corresponding pulse current waveform; Within each pulse cycle of the pulse current waveform output by the welding power source, the length of the arc is stabilized within the length range corresponding to the arc shape by short-circuit retraction constant arc length control.

6. The method for controlling MIG welding of thick and thin plates according to claim 5, characterized in that, The short-circuit retraction constant arc length control operation specifically includes: For each pulse cycle, the molten droplets are detected in real time; When the necking detection signal of the molten droplet is obtained, the molten droplet is controlled to contact the molten pool according to the preset current adjustment rule, and the molten droplet is cooled for a preset cooling time when it contacts the molten pool. After the cooling process is completed, the length of the electric arc is adjusted according to the length range corresponding to the arc shape by means of a preset retraction operation and a preset thrust current application operation.

7. The method for controlling MIG welding of thick and thin plates according to claim 1, characterized in that, The welding torch uses welding wire with a diameter of 1.6 mm for welding.

8. A MIG welding control system for thick and thin plates, characterized in that, include: The signal acquisition unit is used to acquire the phase signal of the welding torch in real time during the oscillation period when the welding torch oscillates along the welding direction in the butt joint area composed of thick and thin plates according to a preset oscillation period. The judgment unit is used to determine, based on the phase signal, whether the pointing position of the welding gun has reached the limit position on the thick plate side or the limit position on the thin plate side. The parameter generation unit is used to generate welding parameters based on the pulse current and arc voltage corresponding to the extreme position of the thick plate side or the extreme position of the thin plate side when the pointing position reaches the extreme position of the thick plate side or the extreme position of the thin plate side. The control unit is used to control the output of the welding power source based on the welding parameters, and to adjust the arc according to the arc shape corresponding to the extreme position on the thick plate side or the extreme position on the thin plate side. The pulse current corresponding to the extreme position on the thick plate side is greater than the pulse current corresponding to the extreme position on the thin plate side.

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 thick and thin plate MIG welding control method as described in any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the MIG welding control method for thick and thin plates as described in any one of claims 1-7.

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