Multi-modal composite magnetic field intelligent magnetic control welding system and welding control method

Abstract

The application relates to the technical field of electric arc welding, and provides a multi-modal composite magnetic field intelligent magnetic control welding system and a welding control method.The system comprises a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly, a magnetic pole body assembly and a magnetic pole body assembly.

Description

Technical Field

[0001] This invention relates to the field of arc welding technology, and in particular to a multi-modal composite magnetic field intelligent magnetocontrol welding system and welding control method. Background Technology

[0002] In manufacturing fields such as thick plate welding, dissimilar material joining, and all-position precision welding, magnetron arc welding technology uses an external spatial magnetic field to non-contactly control the shape of the welding arc and the flow behavior of the molten pool below it. This can effectively improve the crystallization morphology of the weld structure, refine the grains, and suppress welding defects such as porosity and cracks.

[0003] However, existing transverse magnetic field generating structures typically employ three or more poles densely arranged around the welding torch. This results in severe crosstalk and superposition of magnetic flux between the spatial poles, easily leading to magnetic field distortion and control inaccuracies. Furthermore, the dense coils suffer from limited heat dissipation within the confined space of the welding torch, making long-term operation prone to excessive temperature rise and insulation aging. Existing longitudinal magnetic field generating structures generally place the solenoid coil directly around the periphery of the welding torch tube. With the coil adjacent to the high-temperature radiation zone of the arc, the axial magnetic field exhibits a large attenuation gradient along the depth direction, resulting in severe uneven control force at the root and top of the deep bevel. Moreover, traditional devices often operate with a single magnetic field independently, lacking the flexible reconfiguration capability between transverse, longitudinal, and composite magnetic fields. Summary of the Invention

[0004] This invention provides a multi-modal composite magnetic field intelligent magnetic control welding system and welding control method, realizing a multi-modal composite magnetic field intelligent magnetic control welding scheme that can externally protect the excitation coil and adaptively recombine multiple magnetic field modes.

[0005] In a first aspect, the present invention provides a multi-modal composite magnetic field intelligent magnetic control welding system, comprising: a magnetic pole assembly including two magnetic poles, the two magnetic poles including a first magnetic pole arranged on the welding torch side of the welding area, and a second magnetic pole arranged on the workpiece side away from the welding torch; an external excitation assembly including multiple excitation coils arranged in a protective area; wherein the distance from the protective area to the welding area is greater than or equal to a first distance; multiple flexible magnetic wire bundles, the two ends of each flexible magnetic wire bundle being respectively connected to the corresponding excitation coil and the magnetic pole, for conducting the magnetic flux generated by the excitation coil to the corresponding magnetic pole; and a polarity reconfiguration switch matrix electrically connected between the excitation power supply and each of the excitation coils, for reconfiguring the circuit on / off state and current flow direction of each of the excitation coils according to control commands, so as to excite at least one of a transverse magnetic field mode, a longitudinal magnetic field mode, or a transverse-longitudinal composite magnetic field mode in the welding area.

[0006] In some embodiments, the first magnetic pole body is mounted on the neck of the welding torch via a rotating clamp, the rotating clamp being used to adjust the spatial angle between the line connecting the geometric centers of the two semi-annular magnetic pole bodies in the first magnetic pole body and the weld seam direction of the workpiece; wherein the adjustment range of the spatial angle is 0° to 90°; the second magnetic pole body is disposed on a follower mechanism, the follower mechanism being used to drive the second magnetic pole body to maintain a spatially relative position lock with the first magnetic pole body during the welding process.

[0007] In some embodiments, the flexible magnetic conductor bundle is formed by twisting together multiple mutually insulated magnetic conductor monofilaments, and the outer periphery of the flexible magnetic conductor bundle is covered with an insulating protective layer. The permeability of the flexible magnetic conductor bundle is matched with that of the magnetic pole body.

[0008] In some embodiments, the magnetic flux mating end of the magnetic pole body is provided with a mating groove that gradually narrows from the groove opening to the groove bottom, and the end of the flexible magnetic wire bundle is formed into a wedge-shaped end that matches the slope of the mating groove; a magnetic dielectric layer is provided between the wedge-shaped end and the mating surface of the mating groove; and / or, a non-magnetic insulating limiting member is provided at the groove opening of the mating groove to mechanically lock the wedge-shaped end.

[0009] In some embodiments, the first magnetic pole body includes a first semi-annular magnetic pole body and a second semi-annular magnetic pole body, the second magnetic pole body includes a third semi-annular magnetic pole body and a fourth semi-annular magnetic pole body, and the external excitation assembly includes four sets of excitation coils respectively connected to the first semi-annular magnetic pole body to the fourth semi-annular magnetic pole body; the polarity reconfiguration switch matrix is ​​electrically connected between the excitation power supply and the four sets of excitation coils, and includes at least one of the following switch groups: an upper bridge arm switch group for constructing a horizontal transverse magnetic field on the welding torch side; a lower bridge arm switch group for constructing a transverse magnetic field on the workpiece side; and an interlayer switching switch group for constructing an axially penetrating longitudinal magnetic field or a three-dimensional intersecting transverse and longitudinal composite magnetic field.

[0010] In some embodiments, the first lead of the first semi-annular magnetic pole is electrically connected to the first switch, and the second lead is electrically connected to the second and third switches; the first lead of the second semi-annular magnetic pole is electrically connected to the fourth to sixth switches, and the second lead is electrically connected to the seventh and eighth switches; the first lead of the third semi-annular magnetic pole is electrically connected to the ninth and tenth switches, and the second lead is electrically connected to the eleventh to thirteenth switches; the first lead of the fourth semi-annular magnetic pole is electrically connected to the fourteenth and fifteenth switches, and the second lead is electrically connected to the sixteenth to seventeenth switches.

[0011] In some embodiments, the device further includes at least one of the following components: an arc vision sensing component, arranged toward the welding arc, for acquiring arc contour morphology and / or droplet transition images; a temperature acquisition component, arranged toward the weld pool, for acquiring weld pool temperature field data; a welding electrical parameter monitoring component, electrically connected to the main circuit output terminal of the welding power supply, for acquiring current and / or voltage signals of the welding main circuit; and a spatial magnetic field feedback component, attached to the working end face of the first magnetic pole and / or the second magnetic pole, for acquiring at least one parameter among the magnetic field strength, polarity direction, and alternating frequency of the arc region.

[0012] Secondly, the present invention also provides a multi-modal composite magnetic field intelligent magnetic control welding control method for controlling the multi-modal composite magnetic field intelligent magnetic control welding system as described in the first aspect. The method includes: obtaining a target magnetic field mode corresponding to a target welding condition; controlling the polarity reconfiguration switch matrix to switch to a loop connection topology corresponding to the target magnetic field mode, and controlling the excitation power supply to output excitation current to the excitation coil; wherein the excitation current excites the excitation coil to generate magnetic flux, the magnetic flux is conducted to the first magnetic pole and the second magnetic pole via the flexible magnetic conductor bundle, and at least one of a transverse magnetic field mode, a longitudinal magnetic field mode, or a transverse-longitudinal composite magnetic field mode is excited in the welding area.

[0013] In some embodiments, exciting at least one of a transverse magnetic field mode, a longitudinal magnetic field mode, or a combined transverse and longitudinal magnetic field mode in the welding zone includes: passing an alternating excitation current through the two excitation coils on the welding torch side to generate a transverse magnetic field with periodic polarity reversal in the first magnetic pole body; wherein, when the spatial angle between the line connecting the geometric centers of the two semi-annular magnetic pole bodies in the first magnetic pole body and the weld seam direction of the workpiece is equal to 0°, the electric arc is driven to oscillate reciprocally along the weld seam direction; when the spatial angle is equal to 90°, the electric arc is driven to oscillate reciprocally along the weld seam direction; passing a DC excitation current through the two excitation coils on the workpiece side to generate a transverse magnetic field with periodic polarity reversal in the second magnetic pole body. A transverse magnetic field parallel to the weld direction is generated, and an auxiliary current is applied to the workpiece in a direction perpendicular to the weld, inducing an upward electromagnetic force at the bottom of the molten pool. The first magnetic pole body is controlled to be excited in phase with the first polarity and the second magnetic pole body is controlled to be excited in phase with the second polarity, constructing a longitudinal magnetic field penetrating along the arc axis in the welding zone, driving the charged particles of the arc to make centripetal spiral motion to compress the arc and drive the molten pool to rotate and convection. The polarity reconfiguration switch matrix is ​​controlled to form a cross differential connection topology, synchronously exciting transverse magnetic field components and longitudinal magnetic field components in the welding zone. The transverse magnetic field component is used to drive the arc to deflect to a preset unilateral direction, and the longitudinal magnetic field component is used to maintain the axial convergence of the arc.

[0014] In some embodiments, the method further includes: obtaining multi-source sensing parameters during the welding process; wherein the multi-source sensing parameters include arc images, molten pool temperature field data, welding main circuit electrical parameters, and actual magnetic field parameters; performing feature extraction and fusion analysis on the multi-source sensing parameters to obtain working condition features; wherein the working condition features include bevel geometry, assembly gap size, base material heat dissipation symmetry, and droplet transition stability; and dynamically adjusting the target magnetic field mode and the excitation parameters of the excitation coil according to the working condition features.

[0015] This invention eliminates high-temperature spatter losses and extends system life. Because the excitation coil is located in a protected area far from the welding zone, and the first and second magnetic poles at the working end are passive structures, the high-temperature heat radiation and metal spatter generated during welding cannot directly act on the energized coil body. The coil insulation layer avoids high-temperature baking aging and spatter ablation, significantly improving system reliability. It also reduces the load on the welding torch end and enhances movement flexibility. Since the flexible magnetic wire bundle guides the magnetic flux, the welding torch end does not need to carry a bulky excitation coil and its cooling shell, significantly reducing the load and inertia at the actuator end, improving the dynamic response speed and spatial mobility of the automated welding robot. Furthermore, it broadens process adaptability and reduces magnetic field distortion. By reconfiguring the polarity reversal switch matrix to recombine the energizing state of each coil, the same set of separate magnetic hardware can flexibly switch between generating transverse, longitudinal, and composite magnetic field modes, avoiding the spatial magnetic field interference and severe distortion caused by the traditional dense arrangement of multiple magnetic poles in a small area, thus improving the adaptive control capability for complex welding conditions. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a three-dimensional structural diagram of a split excitation structure in a multimodal composite magnetic field intelligent magnetic control welding system provided by an embodiment of the present invention; Figure 2 This is a three-dimensional structural diagram of the internal structure of a split excitation structure in a multimodal composite magnetic field intelligent magnetic control welding system provided in an embodiment of the present invention; Figure 3 This is a wiring diagram of a multi-modal composite magnetic field intelligent magnetron welding system provided in an embodiment of the present invention; Figure 4This is a schematic diagram of the angle between the line connecting the centers of the magnetic pole pairs and the welding direction in a multimodal composite magnetic field intelligent magnetic control welding system provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the embedded connection between magnetic poles and magnetic wires in a multimodal composite magnetic field intelligent magnetic control welding system provided in an embodiment of the present invention; Figure 6 This is a flowchart illustrating a multi-modal composite magnetic field intelligent magnetron welding control method provided in an embodiment of the present invention; Figure 7 This is a DC magnetic field excitation current waveform diagram provided in an embodiment of the present invention; Figure 8 This is an AC magnetic field excitation current waveform diagram provided in an embodiment of the present invention; Figure 9 This is a wiring diagram of a welding torch-side transverse magnetic field generating circuit provided in an embodiment of the present invention; Figure 10 This is a three-dimensional schematic diagram of the spatial distribution of the transverse AC magnetic field on the welding torch side provided in an embodiment of the present invention; Figure 11 This is a schematic diagram of the force principle of a magnetized arc and a molten pool when the included angle of the transverse alternating magnetic field on the welding torch side is equal to 0°, provided by an embodiment of the present invention. Figure 12 This is a schematic diagram of the force principle of a magnetized arc and a molten pool when the included angle of the transverse alternating magnetic field on the welding torch side is equal to 90°, provided by an embodiment of the present invention. Figure 13 This is a wiring diagram of a workpiece-side transverse magnetic field generating circuit provided in an embodiment of the present invention; Figure 14 This is a stereoscopic view of the transverse magnetic field space on the workpiece side provided by an embodiment of the present invention; Figure 15 This is a cross-sectional schematic diagram of the force principle of a workpiece side transverse DC magnetic field magnetron sputtering molten pool support provided by an embodiment of the present invention; Figure 16 This is a wiring diagram of a longitudinal magnetic field generating circuit provided in an embodiment of the present invention; Figure 17 This is a three-dimensional perspective schematic diagram of the spatial distribution of a longitudinal DC magnetic field provided in an embodiment of the present invention; Figure 18 This is a schematic diagram of the longitudinal DC magnetic field arc focusing and rotating convection magnetocontrol principle provided by an embodiment of the present invention; Figure 19 This is a wiring diagram of a horizontal and vertical composite magnetic field generating circuit provided in an embodiment of the present invention; Figure 20 This is a three-dimensional perspective diagram of the spatial distribution of a horizontal and vertical DC composite magnetic field provided in an embodiment of the present invention; Figure 21 This is a cross-sectional schematic diagram of the principle of magnetic arc deflection and stiffness maintenance by a transverse and longitudinal DC composite magnetic field provided in an embodiment of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0019] Figure 1 This is a three-dimensional structural diagram of a split excitation structure in a multimodal composite magnetic field intelligent magnetic control welding system provided by an embodiment of the present invention. Figure 2 This is a three-dimensional structural diagram of the internal structure of a split excitation structure in a multimodal composite magnetic field intelligent magnetic control welding system provided in an embodiment of the present invention. Figure 3 This is a wiring diagram of a multi-modal composite magnetic field intelligent magnetron welding system provided in an embodiment of the present invention. (Combined with...) Figures 1 to 3 The multi-modal composite magnetic field intelligent magnetic control welding system includes a magnetic pole assembly, an external excitation assembly, multiple flexible magnetic wire bundles 5, and a polarity reconfiguration switch matrix. The magnetic pole assembly includes two magnetic poles: a first magnetic pole 1 arranged on the welding torch side of the welding zone, and a second magnetic pole 3 arranged on the workpiece 2 away from the welding torch. The two magnetic poles are passive structures without built-in excitation coils 4. The external excitation assembly includes multiple excitation coils 4 arranged in a protective zone away from the welding zone, i.e., the distance from the protective zone to the welding zone is greater than or equal to a first distance. The first end of each flexible magnetic wire bundle 5 is connected to the corresponding excitation coil 4, and the second end is connected to the corresponding magnetic pole, used to conduct the magnetic flux generated by the excitation coil 4 to the corresponding magnetic pole. The polarity reconfiguration switch matrix is ​​electrically connected between the excitation power supply and each excitation coil 4, used to reconfigure the circuit on / off state and current flow direction of each excitation coil 4 according to control commands, so as to excite at least one of the transverse magnetic field mode, longitudinal magnetic field mode, or transverse-longitudinal composite magnetic field mode in the welding zone.

[0020] Specifically, a multimodal composite magnetic field intelligent magnetic control welding system refers to a complete welding equipment system capable of autonomously switching between various spatial magnetic field forms, such as transverse magnetic field, longitudinal magnetic field, or transverse-longitudinal composite magnetic field, according to real-time working conditions, and adaptively electromagnetically controlling the arc morphology and molten pool flow behavior. A magnetically conductive pole assembly refers to a collection of passive magnetically conductive components made of magnetically conductive material, arranged on both sides of the welding operation area of ​​workpiece 2, used to guide magnetic flux and release a preset magnetic field distribution in space. The first magnetically conductive pole 1 refers to a magnetically conductive component located on the welding torch side to establish a magnetic pole distribution in the near-arc region. The second magnetically conductive pole 3 refers to a magnetically conductive component located on the side of workpiece 2 away from the welding torch to construct a magnetic flux loop on the back of workpiece 2. A passive structure refers to a purely mechanical magnetically conductive entity whose internal structure does not contain an energized excitation coil 4, serving only as a magnetically conductive medium to conduct externally introduced magnetic flux. An external excitation assembly refers to a coil component used to generate the original excitation magnetic flux. A protective zone refers to an independent, safe installation area spatially away from the high-temperature heat radiation, strong light, and molten metal spatter of the welding arc. The flexible magnetic conductor bundle 5 refers to a low-resistivity flux transmission cable bundle made of high-permeability material with three-dimensional bendability. The polarity reconfiguration switch matrix refers to a circuit switching network electrically connected between the excitation power supply and each excitation coil 4, used to switch the on / off combinations of switches according to control commands to change the connection state of each coil and the direction of current flow. The transverse magnetic field mode refers to a magnetic field pattern where the magnetic field lines mainly intersect the arc axis. The longitudinal magnetic field mode refers to a magnetic field pattern where the magnetic field lines mainly parallel to the arc axis. The combined transverse and longitudinal magnetic field mode refers to a three-dimensional spatial magnetic field pattern in the arc region where components perpendicular to and parallel to the arc axis are simultaneously superimposed.

[0021] The electrical energy output from the excitation power supply is distributed to the external excitation assembly located within the protective zone via a polarity reconfiguration switch matrix. When the excitation coil 4 in the external excitation assembly is energized, it generates initial excitation flux. Multiple flexible magnetic conductor bundles 5 serve as magnetic circuit transmission channels, guiding the flux from the protective zone across spatial distances to the first magnetic conductor 1 on the welding torch side and the second magnetic conductor 3 on the back of the workpiece 2. The first and second magnetic conductors 1 and 3, acting as passive magnetic poles, converge the flux and release it in the welding zone, forming a closed magnetic field distribution that spans or penetrates the welding zone. The polarity reconfiguration switch matrix reconfigures the current flow direction and circuit continuity of each excitation coil 4 according to externally input control commands, thereby changing the magnetic polarity of each magnetic conductor end face, and controlling the generation of transverse, longitudinal, or transverse-longitudinal composite magnetic field modes in the welding zone. The directional charged particle stream in the arc and the liquid conductive metal inside the molten pool, when moving in the external magnetic field, are subjected to Lorentz forces, resulting in controlled morphological changes and convection.

[0022] Therefore, this embodiment of the invention eliminates high-temperature spatter losses and extends lifespan. Since the excitation coil 4 is located in a protective zone far from the welding area, and the first and second magnetic poles 1 and 3 at the working end are passive structures, the high-temperature heat radiation and metal spatter generated during welding cannot directly act on the energized coil body. The coil insulation layer avoids high-temperature baking aging and spatter erosion, significantly improving the system's operational reliability. It also reduces the load on the welding torch end and improves movement flexibility. Because the flexible magnetic wire bundle 5 guides the magnetic flux, the welding torch end does not need to carry the bulky excitation coil 4 and its cooling shell, significantly reducing the load and inertia at the actuator end, improving the dynamic response speed and spatial mobility of the automated welding robot. Furthermore, it broadens process adaptability and reduces magnetic field distortion. By reconfiguring the polarity reversal switch matrix to reorganize the energizing state of each coil, the same set of split magnetic hardware can flexibly switch between generating transverse, longitudinal, and composite magnetic field modes, avoiding the spatial magnetic field interference and severe distortion caused by the traditional dense arrangement of multiple magnetic poles in a small area, thus improving the adaptive control capability for complex welding conditions.

[0023] Figure 4 This is a schematic diagram illustrating the angle between the line connecting the centers of the magnetic pole pairs and the welding direction in a multimodal composite magnetic field intelligent magnetocontrol welding system provided in an embodiment of the present invention. (Combined with...) Figures 1 to 4 The first magnetic pole 1 is mounted on the neck of the welding torch via a rotating clamp. The rotating clamp is used to adjust the spatial angle between the line connecting the geometric centers of the two semi-annular magnetic poles in the first magnetic pole 1 and the direction of the weld seam 7 on the workpiece. The adjustment range of the spatial angle is 0° to 90°. The second magnetic pole 3 is mounted on a follower mechanism. The follower mechanism is used to drive the second magnetic pole 3 to maintain a spatial relative position lock with the first magnetic pole 1 during the welding process.

[0024] Specifically, the rotary clamp refers to a mechanical clamping component that is securely installed on the neck of the welding torch and can drive the magnetic pole body mounted on it to rotate around the welding torch axis at a preset angle for adjustment and locking. The spatial angle refers to the angle between the line connecting the geometric symmetry centers of the two semi-annular magnetic pole bodies in the first magnetic pole body 1 on the horizontal projection plane and the direction of the straight weld seam 7 on the workpiece 2, denoted as α. The follow-up mechanism refers to the mechanical drive mechanism that carries the second magnetic pole body 3 and maintains linkage and coordinated movement with the welding torch motion control system during the welding process.

[0025] The rotating fixture drives the first magnetic pole 1 to rotate around the neck of the welding torch, allowing adjustment of the spatial relative orientation of the two semi-annular magnetic poles and the weld seam 7 on the workpiece within a range of 0° to 90°. When the spatial angle α equals 0°, the poles are parallel to the weld seam 7, and the transverse magnetic field generated between the poles is along the weld seam 7. When the spatial angle α equals 90°, the poles are perpendicular to the weld seam 7, and the transverse magnetic field generated between the poles is transverse to the weld seam 7. During the welding process as the welding torch travels along the weld seam 7, the follower mechanism drives the second magnetic pole 3 below the workpiece 2 to move synchronously, ensuring that it is always directly opposite the first magnetic pole 1 above in spatial projection, maintaining a locked spatial relative position.

[0026] Therefore, this embodiment of the invention flexibly changes the direction of electromagnetic force to adapt to different defect treatments. Based on the interaction between the arc current vector and the magnetic induction intensity vector, when the rotating fixture adjusts the spatial angle to 0°, the transverse magnetic field causes the arc to be subjected to a lateral force perpendicular to the weld seam 7, driving the arc to oscillate back and forth on both sides of the weld seam 7 to widen the weld width and eliminate incomplete fusion of the sidewalls. When the spatial angle is adjusted to 90°, the transverse magnetic field causes the arc to be subjected to a longitudinal force along the weld seam 7, driving the arc to stretch and oscillate back and forth along the weld bead, extending the liquid existence time at the tail of the molten pool to promote the escape of pores and eliminate undercut humps. The symmetry and stability of the spatial magnetic field are ensured. The follower mechanism keeps the spatial relative position locked between the second magnetic pole 3 and the first magnetic pole 1 during the journey, ensuring that the axial magnetic circuit penetrating the workpiece 2 does not produce eccentric displacement during the journey, and preventing abnormal arc blow due to geometric asymmetry of the magnetic circuit.

[0027] In some embodiments, both the first magnetic pole body 1 and the second magnetic pole body 3 include two semi-annular magnetic pole structures formed by stacking magnetic sheet-like structures, with an interlayer insulating coating between the magnetic sheet-like structures.

[0028] Specifically, the magnetic sheet structure refers to a sheet-like stacked unit made of a highly magnetically permeable metal material. The interlayer insulating coating refers to an insulating thin film layer attached between the contact surfaces of adjacent magnetic sheet structures to block the macroscopic conductive path between layers. Both the first magnetic pole 1 and the second magnetic pole 3 are formed by axially pressing and stacking magnetic sheet structures coated with the interlayer insulating coating. When an alternating magnetic flux passes through the magnetic pole, induced eddy currents are generated inside the magnetic material according to the principle of electromagnetic induction. The interlayer insulating coating cuts off the current path across the multiple sheet structures, confining the induced eddy currents within the small thickness cross-section of each individual magnetic sheet structure.

[0029] Therefore, the embodiments of the present invention significantly suppress alternating eddy current heat loss and magnetic field distortion. Since the induced eddy current loss is proportional to the square of the thickness of a single magnetic cross-section, the large cross-section solid is divided into multiple small conductive units by using a laminated structure with inter-sheet insulation, which significantly reduces the eddy current heat loss under alternating excitation conditions, avoids the degradation of permeability caused by excessive temperature rise of the pole body, and suppresses the waveform distortion interference of the self-generated reverse magnetic field of eddy current on the spatially controlled magnetic field.

[0030] Figure 5 This is a schematic diagram illustrating the embedded connection between magnetic poles and magnetic wires in a multimodal composite magnetic field intelligent magnetic control welding system provided by an embodiment of the present invention. (Combined with...) Figures 1 to 5 The flexible magnetic conductor bundle 5 is made of multiple strands of mutually insulated magnetic conductors twisted together. The outer periphery of the flexible magnetic conductor bundle 5 is covered with an insulating protective layer 8. The permeability of the flexible magnetic conductor bundle 5 is matched with that of the magnetic pole body.

[0031] Specifically, the magnetically conductive monofilament refers to a fine metal wire unit with high magnetic permeability. The insulating protective layer 8 refers to the polymer or inorganic sheath layer covering the outermost layer of the stranded wire bundle, providing insulation, isolation, and abrasion resistance. Magnetic permeability matching means that the relative magnetic permeability of the flexible magnetically conductive wire bundle 5 is in a similar value range to the relative magnetic permeability of the magnetically conductive pole material, avoiding abrupt changes in interfacial magnetic reluctance.

[0032] The flexible magnetic conductor bundle 5 is internally composed of numerous fine magnetic conductor monofilaments with an insulating layer attached to their outer surface, twisted together, and externally covered with an insulating protective layer 8. Each magnetic conductor monofilament forms an isolated microscopic magnetic channel, and the magnetic flux is conducted in parallel within multiple channels. Because the permeability of the bundle and the pole body are matched, the magnetic resistance at the interface remains smooth and continuous when the magnetic flux is transitioned from the bundle to the pole body.

[0033] Therefore, this embodiment of the invention eliminates skin heating of the wire harness and reduces magnetic leakage: the mutually insulated monofilament microstructure cuts off the large-scale alternating current loop inside the wire harness, suppressing the skin effect and eddy current loss under high-frequency and alternating operating conditions. The permeability of the flexible magnetic wire harness 5 is matched with that of the magnetic pole body. According to the principle of magnetic circuit continuity, the magnetic reluctance abrupt change at the connection interface is significantly reduced, thereby reducing magnetic leakage and stray radiation of magnetic lines of force from the docking interface to the external space.

[0034] In some embodiments, combined with Figures 1 to 5 The magnetic flux docking end of the magnetic pole body is provided with a mating groove that gradually narrows from the groove opening to the groove bottom. The end of the flexible magnetic wire bundle 5 is formed into a wedge-shaped end 9 that matches the slope of the mating groove. A magnetic medium layer is provided between the wedge-shaped end 9 and the mating surface of the mating groove. And / or, a non-magnetic insulating limiting member 10 is provided at the groove opening of the mating groove to mechanically lock the wedge-shaped end 9.

[0035] Specifically, the mating groove refers to a contracting mating structure formed at the magnetic flux input end of the magnetic pole body, with its cross-section gradually sloping and converging from the groove opening to the bottom. The wedge-shaped end 9 refers to the flexible magnetic wire harness 5, whose end is molded and has an inclined joint on its outer surface that matches the inclination angle of the mating groove. The magnetic medium layer refers to the magnetic paste or adhesive layer filling the microscopic gaps between the wedge-shaped end 9 and the mating groove. The non-magnetic insulating limiting component 10 refers to a mechanical clamping component made of non-ferromagnetic and insulating material, installed at the opening of the mating groove to prevent the end from axially retracting.

[0036] The wedge-shaped end 9 of the flexible magnetic wire bundle 5 is pushed into the mating groove of the magnetic pole body, and the inclined surfaces of the two form an interference self-locking. A magnetic dielectric layer is coated between the mating surfaces to fill the air gaps formed by the micro-roughness of the metal interface. A non-magnetic insulating limiting component 10 is installed at the opening of the mating groove to mechanically press and limit the wedge-shaped end 9.

[0037] Therefore, this embodiment of the invention reduces contact magnetic resistance and improves vibration-resistant mechanical reliability. By utilizing a mechanical wedge fit and filling with a magnetically conductive medium layer, the microscopic air gap at the mating interface is eliminated. Since the permeability of air is much lower than that of magnetically conductive materials, eliminating the air gap significantly reduces the contact magnetic resistance at the magnetic circuit interface, ensuring efficient and smooth transition of magnetic flux. The non-magnetic insulating limiting component 10 rigidly locks the ends, preventing them from loosening under long-term vibration conditions, and the non-magnetic insulating material does not form additional stray magnetic circuits or induced eddy current circuits.

[0038] In some embodiments, the first magnetic pole body 1 includes a first semi-annular magnetic pole body 61 and a second semi-annular magnetic pole body 62, the second magnetic pole body 3 includes a third semi-annular magnetic pole body 63 and a fourth semi-annular magnetic pole body 64, and the external excitation assembly includes four sets of excitation coils 4 respectively connected to the first semi-annular magnetic pole body 61 to the fourth semi-annular magnetic pole body 64; the polarity reconfiguration switch matrix is ​​electrically connected between the excitation power supply and the four sets of excitation coils 4, and includes at least one of the following switch groups: an upper bridge arm switch group for constructing a horizontal transverse magnetic field on the welding torch side; a lower bridge arm switch group for constructing a transverse magnetic field on the workpiece side; and an interlayer switching switch group for constructing an axially penetrating longitudinal magnetic field or a three-dimensional intersecting transverse and longitudinal composite magnetic field.

[0039] Specifically, the first and second semi-annular magnetic pole bodies 62 refer to the magnetically conductive components symmetrically arranged on the left and right sides of the welding torch, and the third and fourth semi-annular magnetic pole bodies 64 refer to the magnetically conductive components symmetrically arranged on the left and right sides of the back of the workpiece 2. The four sets of excitation coils 4 refer to four independently energized coil units externally mounted and connected to the first to fourth semi-annular magnetic pole bodies 64 respectively via four flexible magnetically conductive wire bundles 5. The upper bridge arm switch group refers to the set of switches controlling the coil circuits corresponding to the first and second semi-annular magnetic pole bodies 62. The lower bridge arm switch group refers to the set of switches controlling the coil circuits corresponding to the third and fourth semi-annular magnetic pole bodies 64. The inter-layer switching switch group refers to the set of switches controlling the formation of series-parallel and cross-differential topologies of the upper and lower coils.

[0040] When the upper bridge arm switch group is turned on, the two sets of coils on the welding torch side are energized, generating a transverse magnetic field that passes through the electric arc between the first and second semi-annular magnetic poles 62. When the lower bridge arm switch group is turned on, the two sets of coils on the back of the workpiece 2 are energized, generating a transverse magnetic field between the third and fourth semi-annular magnetic poles 64. When the interlayer switching switch group is turned on, the four sets of coils form a linked topology: if the upper two poles exhibit the first polarity and the lower two poles exhibit the second polarity, an axial longitudinal magnetic field penetrating the workpiece 2 is generated in space. If the four sets of coils form a cross differential connection, a three-dimensional composite magnetic field with horizontal transverse components and axial longitudinal components is simultaneously synthesized in space.

[0041] Therefore, the embodiments of the present invention establish a functional matrix topology and reduce the system reconfiguration complexity. The four magnetic poles are clearly associated with the four coils, and the functional logic is divided by three types of switch groups: upper bridge arm, lower bridge arm, and inter-layer switching. This allows the system to transiently reconfigure between multiple modes such as lateral swing on the welding torch side, lateral lifting on the workpiece side, spatial axial arc stabilization, and three-dimensional composite deflection without modifying any external mechanical connections, relying solely on the on / off switching of pure electrical switches. This improves the modularity and operational reliability of the control system.

[0042] In some embodiments, the first lead of the first semi-annular magnetic pole 61 is electrically connected to the first switch, and the second lead is electrically connected to the second and third switches; the first lead of the second semi-annular magnetic pole 62 is electrically connected to the fourth to sixth switches, and the second lead is electrically connected to the seventh and eighth switches; the first lead of the third semi-annular magnetic pole 63 is electrically connected to the ninth and tenth switches, and the second lead is electrically connected to the eleventh to thirteenth switches; the first lead of the fourth semi-annular magnetic pole 64 is electrically connected to the fourteenth and fifteenth switches, and the second lead is electrically connected to the sixteenth to seventeenth switches.

[0043] Specifically, switches one through seventeen refer to the seventeen independently controlled bidirectional switching elements configured in the polarity reconfiguration switch matrix, denoted as K1 through K17 respectively. The first and second lead terminals refer to the two electrical terminals of the excitation coil 4 corresponding to each magnetic pole body. The first semi-annular magnetic pole body 61 through the fourth semi-annular magnetic pole body 64 correspond to the first through fourth coils. The first end of the first coil is connected to the first switch, and the second end is connected to the second and third switches. The first end of the second coil is connected to the fourth, fifth, and sixth switches, and the second end is connected to the seventh and eighth switches. The first end of the third coil is connected to the ninth and tenth switches, and the second end is connected to the eleventh, twelfth, and thirteenth switches. The first end of the fourth coil is connected to the fourteenth and fifteenth switches, and the second end is connected to the sixteenth and seventeenth switches.

[0044] When different modes need to be stimulated, the controller selects specific switch combinations. For example, K1, K2, K5, and K7 are turned on to form a transverse circuit on the welding torch side; K10, K12, K14, and K16 are turned on to form a transverse circuit on the workpiece side; K1, K3, K6, K8, K10, K13, K14, and K17 are turned on to form a longitudinal series circuit; and K1, K2, K4, K7, K9, K11, K15, and K17 are turned on to form a composite differential circuit, etc.

[0045] Therefore, the embodiments of the present invention simplify the switch topology and ensure circuit electrical isolation. By adopting a specific terminal interconnection architecture of seventeen switches, a complete circuit path covering four sets of coils operating independently, in series in the same direction, in series in opposite directions, and cross differential is constructed with the fewest possible components. This avoids redundant switch settings and ensures circuit isolation and current commutation safety during the switching process of each working mode.

[0046] In some embodiments, the multimodal composite magnetic field intelligent magnetron welding system further includes at least one of the following components: an arc vision sensing component, arranged toward the welding arc, for acquiring arc contour morphology and / or droplet transition images; a temperature acquisition component, arranged toward the weld pool, for acquiring weld pool temperature field data; a welding electrical parameter monitoring component, electrically connected to the main circuit output terminal of the welding power supply, for acquiring current and / or voltage signals of the welding main circuit; and a spatial magnetic field feedback component, attached to the working end face of the first magnetic pole 1 and / or the second magnetic pole 3, for acquiring at least one parameter among the magnetic field strength, polarity direction, and alternating frequency of the arc region.

[0047] Specifically, the arc vision sensing component refers to an image sensor mounted above the welding torch, covering the arc area, used to acquire the arc morphology and droplet transfer characteristics. The temperature acquisition component refers to a temperature sensor positioned towards the molten pool area, used to acquire the two-dimensional temperature distribution of the molten pool. The welding electrical parameter monitoring component refers to a sensor component electrically connected to the output terminal of the welding power supply main circuit, used to acquire the instantaneous current and arc voltage of the main circuit. The spatial magnetic field feedback component refers to a Hall sensor mounted on the working end face of a magnetically conductive pole, used to detect the actual magnetic field strength, direction, and alternating frequency.

[0048] The arc vision sensing component captures real-time images of the arc geometry and molten droplet transition transients. The temperature acquisition component captures real-time temperature field distribution on the molten pool surface. The welding electrical parameter monitoring component acquires real-time welding current and voltage fluctuation signals in the main circuit. The spatial magnetic field feedback component measures the actual magnetic field parameters released by the magnetic pole in real-time and feeds the measured magnetic field data back to the controller for comparison with preset target values, forming a closed-loop regulation signal.

[0049] Therefore, this embodiment of the invention achieves multi-dimensional state perception and closed-loop output calibration. Through multi-source components, it comprehensively perceives the physical state of the welding area from four dimensions: image, thermal field, electrical signal, and magnetic field, providing complete data input for intelligent control. The spatial magnetic field feedback component detects the actual magnetic field at the pole end face in real time, and can compensate online for the magnetic field strength attenuation caused by coil heating, ensuring the consistency between the output magnetic field and the set control target.

[0050] In some embodiments, the semi-annular inner circumferential surfaces of the first magnetic pole body 1 and the second magnetic pole body 3 are provided with annular micro-hole flow equalization grooves. The flow equalization grooves are connected to an external protective gas source or cooling gas source to form an annular micro-positive pressure air curtain that is sprayed outward in a radial direction on the magnetic pole end face, so as to simultaneously block the high-temperature heat conduction of welding and prevent welding spatter particles from adhering to the magnetic pole surface.

[0051] Specifically, the annular micro-perforated flow equalization groove refers to a gas flow channel groove formed on the semi-annular inner circumferential surface of the magnetic pole body facing the electric arc, with uniformly distributed micro-outlet holes along the circumferential direction. The annular micro-positive pressure gas curtain refers to a gas protective layer with outward dynamic pressure formed on the end face of the magnetic pole by uniformly spraying gas outward radially from the micro-perforations of the flow equalization groove. External protective gas or cooling gas is introduced into the flow equalization groove inside the magnetic pole body through a gas pipe, and the gas is uniformly sprayed outward through the inner circumferential micro-perforations, forming an annular micro-positive pressure gas curtain flowing radially outward at the end faces of the first magnetic pole body 1 and the second magnetic pole body 3.

[0052] Therefore, this embodiment of the invention achieves the effect of preventing splash adhesion and blocking heat conduction. The outward-flowing micro-positive pressure air curtain relies on the dynamic pressure of the flow to prevent high-temperature metal splash particles flying towards the magnetic pole body, thus preventing the splashes from adhering to the pole body surface and causing local magnetic reluctance abrupt changes and magnetic field distortion. The continuously ejected flowing gas simultaneously provides forced convection cooling to the end face of the magnetic pole body, blocking the heat conduction from the high-temperature radiation of the electric arc to the interior of the pole body, maintaining the magnetic material in a lower operating temperature range, and ensuring the stability of the magnetic permeability characteristics.

[0053] In some embodiments, the follower mechanism of the second magnetic pole 3 includes a biaxial air-floating leveling mechanism and an eddy current displacement sensor. The follower mechanism adjusts the normal gap and horizontal spatial projection position of the second magnetic pole 3 in real time according to the energy center coordinates of the hot spot on the back of the workpiece 2 and the warping displacement signal of the workpiece 2, so that the second magnetic pole 3 and the first magnetic pole 1 maintain axial dynamic alignment under the thermal deformation condition of the workpiece 2.

[0054] Specifically, the dual-axis air-floating leveling mechanism refers to a precision air-floating positioning support mechanism with two-dimensional planar fine-tuning and normal floating compensation functions. The eddy current displacement sensor is a non-contact displacement sensor that uses the principle of high-frequency electromagnetic induction to detect the relative distance to the surface of the conductive workpiece 2. The energy center coordinates of the hot spot in the molten pool on the back of workpiece 2 refer to the energy-weighted geometric center planar coordinates of the high-temperature molten pool region on the back of workpiece 2 extracted by a thermal imaging algorithm. Axial dynamic alignment refers to the dynamic alignment of the central axis of the second magnetic pole 3 with the central axis of the first magnetic pole 1 in three-dimensional space. During the welding of thick plates, workpiece 2 warps due to heat. The eddy current displacement sensor detects the change in the normal distance between the back of workpiece 2 and the second magnetic pole 3 in real time. Simultaneously, combined with the energy center coordinates of the hot spot in the molten pool on the back of workpiece 2, the control system drives the dual-axis air-floating leveling mechanism to adjust the normal gap and horizontal projection position of the second magnetic pole 3 in real time, allowing it to adjust synchronously with the deformation of workpiece 2.

[0055] Therefore, this embodiment of the invention eliminates thermal deformation interference and maintains axial symmetry of the magnetic field. The air-floating mechanism dynamically compensates for the warping deformation of the workpiece 2, preventing mechanical scraping between the second magnetic pole 3 and the thermally deformed workpiece 2. This ensures that the second magnetic pole 3 is always aligned with the energy center of the molten pool, guaranteeing that the longitudinal magnetic lines of force penetrating the workpiece 2 remain perpendicular and aligned even during thermal deformation, thus avoiding magnetic field asymmetry blow defects caused by the tilting of the pole space.

[0056] In some embodiments, a first magnetic field detection element and a second magnetic field detection element are respectively provided at the output end of the excitation coil 4 and the corresponding wedge-shaped slot entrance of the magnetic pole body. The transmission loss attenuation value and phase lag angle are calculated in real time based on the differential signal output by the first magnetic field detection element and the second magnetic field detection element. Based on the attenuation value and lag angle, an anti-phase dynamic pre-distortion compensation current pulse is superimposed on the front end of the excitation current control waveform to counteract the hysteresis response lag of the flexible soft magnetic wire bundle under alternating magnetic flux excitation.

[0057] Specifically, the first magnetic field detection element refers to the magnetic field sensor located at the flux output end of the excitation coil 4. The second magnetic field detection element refers to the magnetic field sensor located at the input end of the magnetic pole slot. The differential signal refers to the deviation signal obtained by subtracting the signals collected by the two magnetic field detection elements. The transmission loss attenuation value refers to the percentage reduction in amplitude of the magnetic flux after transmission through the flexible magnetic wire bundle 5. The phase lag angle refers to the time response lag phase of the alternating magnetic flux output end relative to the input end. The inverse dynamic pre-distortion compensation current pulse refers to the correction current pulse signal with a preset lead overshoot superimposed on the leading edge of the excitation current control waveform.

[0058] The first and second magnetic field detection elements respectively acquire the transient waveforms of magnetic flux at the input and output ends of the wire bundle. The system calculates the differential signal between the two to analyze the amplitude attenuation and phase hysteresis angle of the flexible magnetic wire bundle 5 caused by material temperature rise and magnetic hysteresis. Based on the calculation results, the controller injects an anti-phase dynamic pre-distortion compensation current pulse at the leading edge of the excitation current waveform, using the overshoot of the current leading edge to prematurely offset the material magnetization hysteresis damping.

[0059] Therefore, the embodiments of the present invention eliminate hysteresis and temperature drift of long wire bundles and improve alternating response speed. The flexible magnetic wire bundle 5 has hysteresis loss and temperature drift lag under long-term high-current alternating operation. Through dual-end differential detection and waveform front-end pre-distortion feedforward compensation, the hysteresis response delay in the transmission process can be quickly offset, ensuring that the actual alternating magnetic field waveform reaching the working end of the magnetic pole body maintains high fidelity and eliminating phase distortion in the dynamic oscillation process.

[0060] Figure 6 This is a flowchart illustrating a multimodal composite magnetic field intelligent magnetron welding control method provided in an embodiment of the present invention. The multimodal composite magnetic field intelligent magnetron welding control method can be used to control the multimodal composite magnetic field intelligent magnetron welding system provided in this embodiment of the invention. Figure 6 As shown, the intelligent magnetron welding control method using a multimodal composite magnetic field includes the following steps: S101. Obtain the target magnetic field mode corresponding to the target welding condition.

[0061] S102, control the polarity reconfiguration switch matrix to switch to the loop connection topology corresponding to the target magnetic field mode, and control the excitation power supply to output excitation current to the excitation coil.

[0062] The excitation current excites the excitation coil 4 to generate magnetic flux, which is then conducted to the first magnetic pole 1 and the second magnetic pole 3 via the flexible magnetic wire bundle 5, and at least one of the transverse magnetic field mode, longitudinal magnetic field mode, or transverse-longitudinal composite magnetic field mode is excited in the welding area.

[0063] Specifically, the target welding condition refers to the comprehensive process conditions encountered during welding, including plate thickness, bevel type, assembly gap, and material thermophysical properties. The target magnetic field mode refers to the optimal spatial magnetic field shape and its amplitude and frequency parameters, which are pre-set or adaptively determined based on the target welding condition. The loop connection topology refers to the specific electrical connection relationship formed by the on / off combinations of each switch in the polarity reconfiguration switch matrix.

[0064] The system first acquires the target magnetic field mode corresponding to the target welding condition. The control polarity reconfiguration switch matrix is ​​switched to the corresponding loop connection topology, and the excitation power supply outputs excitation current to the external excitation component. This excitation current excites the excitation coil 4 to generate the initial magnetic flux. The magnetic flux is conducted via the flexible magnetic conductor bundle 5 to the first magnetic conductor 1 and the second magnetic conductor 3, exciting transverse, longitudinal, or combined transverse and longitudinal magnetic field modes in the welding zone space. This applies electromagnetic control to the arc and molten pool to implement welding.

[0065] Therefore, this embodiment of the invention realizes multi-mode standardized control under a split magnetic guide architecture. By mapping the working conditions to the step control of switching matrix topology reconstruction, long-distance flexible magnetic flux conduction and spatial magnetic field release, electrical reconstruction replaces the traditional cumbersome mechanical coil replacement, realizing rapid switching of multiple magnetic field modes on the same hardware platform, ensuring the efficiency and control consistency of the welding process.

[0066] In some embodiments, at least one of a transverse magnetic field mode, a longitudinal magnetic field mode, or a combined transverse and longitudinal magnetic field mode is excited in the welding zone, including: passing an alternating excitation current through the two excitation coils 4 on the welding torch side to generate a transverse magnetic field with periodically reversed polarity in the first magnetic pole body 1; wherein, when the spatial angle between the line connecting the geometric centers of the two semi-annular magnetic pole bodies in the first magnetic pole body 1 and the direction of the weld seam 7 on the workpiece is equal to 0°, the electric arc is driven to oscillate back and forth along the direction perpendicular to the weld seam 7; when the spatial angle is equal to 90°, the electric arc is driven to oscillate back and forth along the direction of the weld seam 7; passing a direct current through the two excitation coils 4 on the workpiece side to generate a transverse magnetic field with periodically reversed polarity in the second magnetic pole body 3. A transverse magnetic field parallel to the direction of weld 7 is generated, and an auxiliary current is applied to workpiece 2 in a direction perpendicular to weld 7, inducing an upward electromagnetic force at the bottom of the molten pool; the first magnetic pole body 1 is controlled to be excited in phase with the first polarity and the second magnetic pole body 3 is controlled to be excited in phase with the second polarity, constructing a longitudinal magnetic field penetrating along the arc axis in the welding zone, driving the charged particles of the arc to make centripetal spiral motion to compress the arc and drive the molten pool to rotate and convection; the polarity reconfiguration switch matrix is ​​controlled to form a cross differential connection topology, and the transverse magnetic field component and the longitudinal magnetic field component are excited synchronously in the welding zone. The transverse magnetic field component is used to drive the arc to deflect to a preset single side, and the longitudinal magnetic field component is used to maintain the axial convergence of the arc.

[0067] Specifically, the transverse AC oscillation control refers to the control process of alternating reversals of the polarity of the magnetic pole body at a preset frequency to generate an alternating transverse magnetic field in the arc zone, thereby driving the arc to oscillate in a regular manner. The workpiece-side transverse DC lifting control refers to the control process of establishing a stable transverse magnetic field on the back of workpiece 2 and, in conjunction with the transverse auxiliary current of workpiece 2, inducing an upward electromagnetic force at the bottom of the molten pool to balance the gravity of the liquid molten pool. The longitudinal arc focusing and swirling control refers to the control process of constructing a longitudinal magnetic field penetrating the arc axis in the welding zone, using tangential Lorentz force to compress the arc and drive the molten pool to rotate and stir. The transverse and longitudinal composite three-dimensional control refers to the control process of simultaneously exciting transverse and longitudinal magnetic field components in the welding zone, achieving coordinated regulation of arc directional deflection and axial constraint.

[0068] Lateral AC oscillation control: Alternating current is supplied to the two coils on the welding torch side, causing the first magnetic pole 1 to generate a periodically reversed lateral magnetic field. The arc is subjected to force perpendicular to the weld seam 7, driving the arc to oscillate laterally on both sides of the weld seam 7. When the spatial angle is 90°, the arc is subjected to force parallel to the weld seam 7, driving the arc to oscillate back and forth along the direction of the weld seam 7. Lateral DC lifting control on the workpiece side: Direct current is supplied to the two coils on the workpiece side, causing the second magnetic pole 3 to generate a DC magnetic field parallel to the weld seam 7. At the same time, an auxiliary current is applied laterally to the workpiece 2. The lateral current at the bottom of the molten pool couples with the parallel magnetic field, generating a Lorentz force pointing vertically upward toward the base material surface to lift the molten pool. Longitudinal arc focusing and swirling current control: The first magnetic pole 1 is controlled to exhibit the first polarity and the second magnetic pole 3 to exhibit the second polarity, forming an axial longitudinal magnetic field penetrating the workpiece 2. The radial diffusion motion of charged particles in the electric arc interacts with the axial magnetic field to generate a circumferential tangential Lorentz force, forcing the charged particles to undergo high-speed helical motion, producing a centripetal compression effect. Simultaneously, the rotating arc drives the molten pool to rotate and stir. A three-dimensional composite control system, using a control switch matrix to form a cross-differential connection, simultaneously excites transverse and longitudinal components in the welding zone. The transverse magnetic field component drives the arc to deflect at a large angle towards the set sidewall, while the longitudinal magnetic field component provides a centripetal contraction force, maintaining the stiffness and energy concentration of the deflected arc.

[0069] Therefore, this invention utilizes transverse AC oscillation to widen the weld width, effectively eliminating the incomplete fusion defect on the sidewall of thick plates with narrow gaps. The transverse AC oscillation also extends the liquid lifespan of the molten pool, eliminating undercut and hump defects in high-speed welding. It prevents the collapse of deep-penetration and highly fluid molten pools; the upward Lorentz force generated by the DC lifting on the workpiece side counteracts the weight of the liquid metal, effectively preventing molten pool runoff and burn-through during wide-gap welding of metals such as aluminum alloys. It increases weld penetration and refines solidified grains; longitudinal arc focusing and swirling significantly improve arc energy density and rigidity, increasing deep-penetration weld penetration and breaking up dendrites, improving weld microstructure segregation. It ensures arc stability during large-angle deflections; the transverse and longitudinal composite control overcomes the defect of arc divergence and instability during large-angle directional deflections, maintaining high penetration capability while achieving asymmetric heat input distribution.

[0070] In some embodiments, the intelligent magnetron welding control method for multimodal composite magnetic fields further includes: The process obtains multi-source sensing parameters during welding, including arc images, molten pool temperature field data, welding main circuit electrical parameters, and actual magnetic field parameters. Feature extraction and fusion analysis are performed on the multi-source sensing parameters to obtain working condition features, including bevel geometry, assembly gap size, base material heat dissipation symmetry, and droplet transition stability. The target magnetic field mode and excitation parameters of excitation coil 4 are dynamically adjusted according to the working condition features.

[0071] Specifically, multi-source sensing parameters refer to a multi-modal data set including arc images, molten pool temperature field data, main circuit current and voltage signals, and actual magnetic field parameters. Operating condition characteristics refer to the feature parameters extracted from the multi-source data that characterize the bevel geometry, assembly gap dimensions, base material heat dissipation symmetry, and droplet transition stability. Dynamic adjustment refers to a closed-loop control process that adaptively reorganizes the current magnetic field mode, target magnetic induction intensity value, direction, and alternating frequency based on changes in operating condition characteristics obtained through online analysis.

[0072] The system acquires real-time images of the arc morphology, molten pool temperature field, main circuit electrical parameters, and actual magnetic field parameters. It performs image denoising, edge extraction, and feature fusion processing on the multi-source data to dynamically identify the bevel type, assembly gap size, unilateral heat dissipation status of the base material, and droplet transition period. Based on the identified operating characteristics, the system automatically matches and determines the optimal magnetic field mode and the corresponding excitation current amplitude, direction, and frequency, sending commands to the switching matrix and excitation power supply to correct the output in real time.

[0073] For example, the arc morphology image, droplet transition image, and molten pool two-dimensional temperature field matrix are input into multiple convolutional and pooling layers of a convolutional neural network. The convolutional kernels extract spatial edge contours and temperature field gradient features, outputting spatial geometric feature vectors representing the bevel cross-sectional contour, assembly gap dimensions, and temperature difference between the left and right sides of the bevel. The welding current sequence and arc voltage sequence within a continuous time window are input into the input gate, forget gate, and cell state of a long short-term memory temporal network to extract the voltage transient drop frequency, current effective value fluctuation rate, and arcing time duty cycle, outputting temporal dynamic feature vectors representing arc stability and droplet transition smoothness levels. The spatial geometric feature vector and the temporal dynamic feature vector are concatenated in a fusion fully connected layer to construct a combined feature vector. The classification layer outputs the current working condition category, and the linear regression layer outputs the target magnetic field physical parameters.

[0074] In addition, after selecting the target magnetic field mode and issuing the initial excitation parameters, the space magnetic field feedback component detects the actual magnetic induction intensity value of the arc region in real time. The controller compares the actual magnetic induction intensity value with the target magnetic induction intensity setpoint output by the algorithm, and uses a proportional-integral-derivative control algorithm to dynamically correct the duty cycle of the excitation power supply output voltage to eliminate the magnetic field intensity temperature drift caused by the increased resistance due to long-term coil heating. At the same time, the arc vision and electrical parameter module continuously monitors the droplet transition stability. When the arc stability index is detected to rise above the stability set threshold, the system locks the current excitation parameters. If the operating condition characteristics change abruptly again, the system re-triggers feature analysis and smoothly switches the magnetic field mode.

[0075] Therefore, this invention improves the anti-interference capability and closed-loop adaptive capability of complex working condition identification. By fusing and analyzing spatial image features, temperature field gradients, and time-series electrical signals, it eliminates the drawback of single sensors being prone to misjudgment under strong arc light interference, significantly improving the accuracy of working condition identification. Dynamically adjusting the magnetic field parameters according to the working conditions achieves an improvement from manual experience-based open-loop setting to fully automatic online closed-loop adaptive control throughout the entire magnetron welding process, ensuring a high degree of consistency in weld quality under complex working conditions such as sudden changes in assembly gaps or asymmetrical heat dissipation.

[0076] The following detailed description of the multimodal composite magnetic field intelligent magnetron welding system and welding control method provided in the embodiments of the present invention will be given with specific examples.

[0077] Figure 1 The image shows a workpiece 2 in a welding operation state. A first magnetic pole body 1 with a semi-circular symmetrical distribution is mounted on the welding gun side above the workpiece 2, and a second magnetic pole body 3 with a semi-circular symmetrical distribution is arranged on the back side below the workpiece 2. Figure 1 The diagram also shows a protective housing 11 and a housing base 12. The four magnetic flux docking ends of the first magnetic pole body 1 and the second magnetic pole body 3 are mechanically connected to a flexible magnetic wire bundle 5. A total of four flexible magnetic wire bundles 5 extend upward and downward and are directed to the high temperature and spatter protection area away from the welding area, so as to establish a low magnetic resistance magnetic flux transmission channel with the four excitation coils 4 in the external excitation assembly.

[0078] Figure 3 The diagram shows four independently configured excitation coils 4, with the upper two sets corresponding to the first and second semi-annular magnetic pole bodies 62 on the welding torch side, and the lower two sets corresponding to the third and fourth semi-annular magnetic pole bodies 64 on the workpiece side, as well as a switch matrix network consisting of the first to the seventeenth switches. The positive and negative input terminals of the excitation power supply are connected to this switch matrix network, and the direction of current flow and series-parallel combination in the four sets of coils are controlled by the on and off states of each switch. Figure 4 The central strip-shaped area extending in the horizontal direction is the butt weld 7 on the workpiece 2. A pair of semi-circular first magnetic pole bodies 1 are arranged on both sides of the welding gun. The angle between the line connecting the geometric symmetry centers of the two semi-circular pole bodies and the straight line direction of the workpiece weld 7 is defined as the spatial angle. In the illustrated state, the line connecting the geometric centers of the two pole bodies is perpendicular to the direction of the weld 7, that is, α equals 90°.

[0079] Figure 5The mechanical fit details inside the housing are shown in detail. The magnetic pole, such as the silicon steel laminate structure, has a mating groove at its flux docking end that gradually narrows from the groove opening to the bottom at an angle of 5° to 10°. The flexible magnetic conductor bundle 5 consists of multiple internally insulated micro-magnetic conductor filaments and an outermost insulating protective layer 8. Its end is shaped into a flat wedge-shaped end 9 with the same slope as the mating groove. The wedge-shaped end 9 is pushed into the mating groove to form a beveled interference fit. A magnetic dielectric layer with a thickness of 0.1mm to 0.2mm, such as magnetic grease, is coated between the mating surfaces. A non-magnetic insulating limiting element 10, such as an insulating pressure plate, is installed between the groove opening and the housing base to mechanically lock and limit the wedge-shaped end 9.

[0080] The closed-loop intelligent magnetic control welding method provided by this invention can automatically identify changes in working conditions such as groove geometry, heat dissipation conditions of the base material, and assembly gap size. It can make real-time decisions on the target magnetic field mode, magnetic induction intensity, direction of action, and alternating frequency, and intelligently adjust the wiring circuit and power supply form of the excitation coil 4. It can flexibly switch between generating various magnetic field modes such as transverse magnetic field mode, longitudinal magnetic field mode, and transverse-longitudinal composite magnetic field mode. By changing the magnetic induction intensity, polarity direction, and alternating frequency, it can achieve intelligent control of various behaviors such as arc deflection and oscillation, arc focusing and stabilization, molten pool stirring and convection, and anti-gravity lifting flow, thereby optimizing the weld formation quality and joint performance. It is suitable for various complex welding scenarios such as thick plate welding, dissimilar material welding, and all-position welding. The split excitation system designed in this invention eliminates the need for an excitation coil 4 built into the welding torch's working end. It can create a controllable magnetic field that is evenly distributed, stable, and not easily distorted. It can also place electrical components such as the excitation coil 4 in a protective zone away from the high-temperature welding area and the impact of spatter, significantly extending the service life of the equipment. At the same time, the overall structure is highly modular, making it easy to integrate into various automated welding equipment.

[0081] In recent years, high-end manufacturing industries, represented by rail transit, have raised stringent requirements for high-precision, high-quality shape and property control in applications such as high-efficiency welding of thick plates and arc additive manufacturing. This has driven the iterative upgrade of welding processes from traditional form-forming welding to precision welding with controllable microstructure and properties. Magnetron arc welding, through a non-contact external magnetic field, actively controls the arc morphology, trajectory, and molten pool flow behavior. It can effectively refine the grain structure of the weld, suppress welding cracks and compositional segregation, significantly improve the fusion quality of the joint sidewalls, and comprehensively enhance the overall performance of the welded joint. Simultaneously, it can significantly broaden the welding process window, adapting to welding conditions of thin plates, thick plates, and complex irregular joints. Furthermore, it is easily integrated with automated and robotic welding systems, possessing broad application prospects and promotional value in high-precision manufacturing fields such as rail transit.

[0082] Currently, most magnetic arc welding devices generate magnetic fields that are independently controlled by a single transverse or longitudinal magnetic field, lacking the ability to couple and coordinate multiple magnetic fields. This makes it difficult to achieve precise and coordinated control of arc morphology, molten pool flow, and solidification. Existing transverse magnetic field generators generally employ a multi-pole layout with three or more poles. The magnetic fields generated by each pole overlap and couple in space, easily causing magnetic field distortion and interference. This results in a significant deviation between the actual magnetic field morphology acting on the arc and molten pool and the theoretical design model and the preset parameters of the control system, leading to a substantial decrease in arc stability and control accuracy. Furthermore, the dense arrangement of multiple excitation coils results in a compact structure, limited heat dissipation space, and challenging heat dissipation design. Under long-term continuous welding conditions, this can easily lead to problems such as excessive temperature rise, parameter drift, and insulation aging, seriously affecting the long-term operational reliability and process reproducibility of the device.

[0083] Existing longitudinal magnetic fields are mostly generated by winding a solenoid coil around the outer periphery of the welding torch tube. The coil is close to the high-temperature radiation zone of the electric arc, which also has the disadvantages of easy aging, high failure rate and short service life. Moreover, the longitudinal magnetic field generated by this structure has poor axial uniformity and large magnetic field gradient. In the welding scenarios of thick plates and deep bevels, the magnetic field strength at the top and bottom of the molten pool is significantly different. The arc constraint effect and molten pool control force in the upper and lower regions are inconsistent, which ultimately makes it difficult to guarantee the consistency of weld formation, grain structure and mechanical properties.

[0084] To address the aforementioned technical problems, the magnetic control welding solution provided by this invention can flexibly switch between various magnetic field modes, such as transverse magnetic field mode, longitudinal magnetic field mode, and transverse-longitudinal composite magnetic field mode, by adjusting the loop on / off and power supply mode of the polarity reconfiguration switch matrix. By changing the magnetic induction intensity, direction of action, and alternating frequency, it can achieve precise control over various behaviors such as arc deflection and oscillation, arc focusing and stabilization, molten pool stirring and convection, and anti-gravity lifting flow, thereby optimizing the weld formation quality and joint performance. It is suitable for various complex welding scenarios such as thick plate welding, dissimilar material welding, and all-position welding.

[0085] The system integrates multiple sensing modules, including arc vision sensing components, temperature acquisition components such as those from a molten pool infrared thermal imager, welding electrical parameter monitoring components, and spatial magnetic field feedback components such as Hall effect sensors. It leverages an industrial network for data exchange, seamlessly connecting edge computing nodes with the factory's central intelligent control system. Equipped with machine learning intelligent analysis models, such as a fusion model of convolutional neural networks and long short-term memory temporal networks, the system can analyze welding data online in real time. It automatically identifies dynamic changes in working conditions, such as bevel geometry, assembly gap dimensions, base material heat dissipation characteristics, and on-site welding posture. It autonomously determines the optimal target magnetic field mode, adaptively matching and adjusting the magnetic field type, output intensity, direction of action, and operating frequency in real time, achieving fully automatic closed-loop intelligent control of the arc and molten pool states.

[0086] The system employs two sets of semi-circular magnetic poles, such as silicon steel sheet stacked magnetic poles, arranged as magnetic pole components. These are positioned on the welding torch side and the workpiece 2 on the side away from the welding torch. This structure can form a dense, uniform, and stable spatial magnetic field distribution, effectively avoiding the magnetic field distortion and magnetic field interference problems caused by traditional small-area, multi-pole dense layouts. Furthermore, it eliminates the need for an internal excitation coil 4 at the welding torch end to construct a longitudinally adjustable magnetic field, structurally ensuring the realization of a split-type excitation system design.

[0087] The system adopts a split excitation architecture, abandoning the traditional integrated design of the excitation coil 4 and the welding torch magnetic poles. It utilizes a highly permeable, flexible magnetic conductor bundle 5 as the magnetic flux transmission carrier, achieving a non-rigid, air-tight connection between the external excitation coil 4 and the working end magnetic pole. Leveraging the excellent magnetic permeability and deformation adaptability of the flexible magnetic conductor bundle 5, while ensuring efficient and low-loss magnetic flux transmission, the excitation coil 4 can be placed in a protected area away from the welding torch's working end, avoiding damage to the device caused by high-temperature radiation and welding spatter, significantly extending the equipment's service life. By constraining the magnetic flux transmission path through the flexible magnetic conductor bundle 5, the system blocks the direct radiation of the excitation coil 4's self-generated stray magnetic field to the arc region, reducing the coupling interference of the coil's stray magnetic field on the arc, thereby obtaining a more regularly distributed and controllable effective magnetic field.

[0088] Furthermore, the split structure significantly reduces the weight and volume of the welding torch tip, which is beneficial for improving the dynamic response speed and mobility of welding robots or automated equipment, providing a reliable magnetic field control basis for precision, high efficiency, and long-term continuous welding. At the same time, since the excitation coil 4 is no longer limited by the small space of the welding torch, it can use an independent high-current coil and be equipped with forced air cooling or water cooling components to generate a stronger dynamic magnetic field.

[0089] Specifically, in combination Figures 1 to 5 The split excitation part of the multimodal composite magnetic field intelligent magnetic control welding system uses a high-permeability, bendable flexible magnetic wire bundle 5 as a magnetic flux transmission carrier to realize a non-rigid, air-tight connection between the excitation coil 4 and the magnetic pole body. It mainly consists of three parts: magnetic pole body assembly, flexible magnetic wire bundle 5, and external excitation assembly.

[0090] The magnetic pole assembly consists of two sets of semi-annular magnetic poles, respectively arranged on the welding torch side and below the workpiece 2 in areas opposite to the welding torch. The first magnetic pole 1 on the welding torch side can be securely mounted on the welding torch neck using a dedicated rotating fixture, such as a tooling fixture. The second magnetic pole 3 below the workpiece 2 moves synchronously with the welding torch during welding via a follower mechanism. The spatial angle between the line connecting the geometric centers of the two semi-annular magnetic poles and the direction of the weld seam 7 on the workpiece can be adjusted according to actual needs. The magnetic poles are formed by stacking magnetic sheet-like structures, for example, using 0.35mm thick cold-rolled non-oriented silicon steel sheets with an overall thickness of 10mm. Interlayer insulating coatings are applied between the sheets to reduce alternating eddy currents, temperature rise, and magnetic field distortion.

[0091] The flexible magnetic conductor bundle 5 can be made of multiple strands of mutually insulated micro-magnetic conductor monofilaments twisted together, such as a flexible magnetic conductor bundle made of multiple strands of ultra-fine electrical pure iron insulated strands. It is covered with an insulating protective layer 8, such as a polyimide or glass fiber insulating sheath, which matches the permeability and saturation magnetic induction characteristics of the silicon steel laminated magnetic poles. The magnetic flux exhibits low magnetic resistance and no significant flux abrupt change at the transition interface between the silicon steel sheet and the flexible magnetic conductor bundle 5, making it less prone to magnetic leakage and magnetic field distortion. The use of monofilament insulation and a multi-strand twisted structure can significantly suppress eddy current losses under alternating excitation.

[0092] The magnetic pole body and the flexible magnetic wire bundle 5 are connected by an embedded mating groove. After the magnetic sheet-like structure is stacked to form an integral magnetic pole, a mating groove that gradually narrows from the groove opening to the bottom is opened at the magnetic flux docking end on the semi-annular rear side. For example, it is a wedge-shaped embedded groove that is wider at the bottom and narrower at the top. The groove shape can be rectangular or arc-shaped, and the inclination angle is preferably 5° to 10°. The outermost insulating protective layer 8 of one end of the flexible magnetic wire bundle 5 is removed, while the insulation layer of each internal magnetic single wire is completely preserved to avoid the generation of alternating eddy currents. The multiple single wire bundles are gathered and shaped, and a cold-forming process is used to press them into a flat wedge-shaped end 9 with the same slope as the mating groove. After the end is shaped, the rear face is flat and free of loose wires, ensuring good contact with the inclined surface of the mating groove. A magnetic conductive medium layer, such as magnetic grease, is uniformly coated on the inner surface of the mating groove and the outer surface of the wedge-shaped end 9. The coating thickness is approximately 0.1 mm to 0.2 mm. The flexible magnetic conductive wire bundle 5 is passed through the large opening end of the silicon steel lamination mating groove, and the wedge-shaped end 9 is pushed into the mating groove. The interference fit of the wedge-shaped inclined surfaces of the two achieves a self-locking and tight fit. A non-magnetic insulating limiting component 10, such as a non-magnetic insulating pressure plate, is added between the groove opening end and the base to mechanically lock and limit the wedge-shaped end 9, preventing the end of the flexible magnetic conductive wire bundle 5 from coming out. The whole adopts a purely mechanical embedding method and no hot melt welding process, which not only greatly reduces the air gap and contact magnetic resistance of the magnetic circuit connection, ensuring stable and low-loss transmission of magnetic flux, but also suppresses alternating eddy current loss. At the same time, the structure is compact, vibration-resistant, and bend-resistant, making it suitable for long-term robotic automated welding conditions.

[0093] The excitation coil 4 is independently wound on the magnetically conductive transition iron core, such as silicon steel or electrical pure iron, to form an external excitation assembly. The external excitation assembly has four sets of independent excitation coils 4. Each set of transition iron cores has a mating groove at one end. The flexible magnetically conductive wire bundle 5 is mated with the transition iron core using an embedded connection method, and is mechanically locked using a non-magnetic insulating limiting member 10.

[0094] For the control method and circuit topology of multimodal composite magnetic field magnetically controlled arc, a corresponding wiring circuit for excitation coil 4 is designed according to different magnetic field requirements. Seventeen sets of control switch units, from the first switch to the seventeenth switch, are configured to form a polarity reconfiguration switch matrix. By controlling the on / off state of each set of switches, the circuit connection form of excitation coil 4 can be flexibly switched.

[0095] Figure 7 This is a DC magnetic field excitation current waveform diagram provided in an embodiment of the present invention. Figure 8 This is a waveform diagram of the excitation current of an alternating magnetic field provided in an embodiment of the present invention. Combined with... Figure 7 and Figure 8 The horizontal axis represents time, and the vertical axis represents the excitation current output from the excitation power supply to the external excitation coil 4. Figure 7 The curve shown is a constant horizontal straight line parallel to the time axis. The current amplitude is stably maintained at the set positive value I1, indicating that the excitation coil 4 is supplied with steady-state DC current to generate a steady-state DC magnetic field with a constant spatial direction, such as constant unidirectional deflection or steady-state arcing. Figure 8 The curve shown is a standard sinusoidal alternating curve. The positive peak current is I1, and the negative reverse peak current is -I1. This indicates that the excitation coil 4 is supplied with alternating current with periodic polarity reversal, which is used to generate a dynamic alternating magnetic field in the welding area, such as driving the arc to oscillate back and forth and the molten pool to convection.

[0096] Combination Figures 1 to 8 Simultaneously, by coordinating the adjustment of the DC or AC excitation current type, current flow direction, and output amplitude, various magnetic field modes can be formed, including transverse magnetic field modes, longitudinal magnetic field modes, and transverse plus longitudinal composite magnetic field modes, thereby achieving precise control over the arc morphology and molten pool flow behavior.

[0097] Figure 9 This is a wiring diagram of a welding torch-side transverse magnetic field generating circuit provided in an embodiment of the present invention. Figure 9 As shown, only the first, second, fifth, and seventh switches in the upper bridge arm switch group are in the closed conducting state, while the rest of the switches are open. The excitation current only flows through the two sets of excitation coils 4 above the welding torch side, while the coil below the workpiece side is de-energized and does not work. Figure 10This is a three-dimensional schematic diagram of the spatial distribution of a transverse AC magnetic field on the welding torch side, provided by an embodiment of the present invention. The left side shows that during the first half-cycle of the AC current, the left magnetic pole of the welding torch is the N pole, and the right magnetic pole is the S pole, forming transverse magnetic lines of force horizontally passing through the arc region from left to right. The lower right side shows that during the second half-cycle of the AC current, the left magnetic pole reverses to the S pole, and the right magnetic pole reverses to the N pole, forming transverse magnetic lines of force horizontally passing through the workpiece 2. The magnetic pole below the workpiece 2 does not exhibit magnetism. That is, the transverse magnetic field mode on the welding torch side, when the first, second, fifth, and seventh switches are on, generates a transverse magnetic field on the first magnetic pole body 1 on the welding torch side after the excitation circuit is powered on. The direction of the magnetic field is perpendicular to the arc axis and is divided into a transverse DC magnetic field and a transverse AC magnetic field. When the excitation current type is DC, a transverse DC magnetic field is generated, with a fixed direction, and the arc will continuously deflect to one side under the action of the Lorentz force. When the excitation current type is AC, a transverse oscillating magnetic field is generated, with the direction of the magnetic field alternating periodically, and the arc will oscillate back and forth under the action of the Lorentz force.

[0098] Depending on the size of the spatial angle between the line connecting the geometric centers of the two semi-annular poles in the first magnetic pole body 1 and the direction of the weld seam 7 on the workpiece, the direction of the transverse magnetic field is different, and the direction of the Lorentz force generated on the electric arc is also different. Figure 11 This is a schematic diagram of the force principle of the magnetically controlled arc and the molten pool when the spatial angle between the transverse alternating magnetic field on the welding torch side is equal to 0°, provided by an embodiment of the present invention. Figure 11 The diagram shows the welding torch 13, electric arc 14, workpiece molten pool 15, and welding power source and auxiliary power source. Since the spatial angle is 0°, the transverse magnetic field direction is parallel to the weld seam 7. Figure 11 The figures are shown perpendicular to the paper inwards and perpendicular to the paper outwards. In the left figure, under an inward magnetic field, the arc experiences a Lorentz force F perpendicular to the weld seam 7 to the left; in the right figure, under an outward magnetic field, the arc experiences a Lorentz force F perpendicular to the weld seam 7 to the right. Simultaneously, under the action of the transverse auxiliary current of workpiece 2, the molten pool metal experiences a Lorentz force F that flows alternately up and down perpendicular to the surface of the base material.

[0099] Therefore, when the transverse magnetic field is parallel to the direction of weld seam 7 on the workpiece and the welding power source is DC reverse polarity, the arc is subjected to a Lorentz force perpendicular to the direction of weld seam 7. When an auxiliary power source is connected to the workpiece 2 in a direction perpendicular to weld seam 7 and an auxiliary current is supplied, the molten pool metal can be subjected to a Lorentz force perpendicular to the surface of the base material. Under the action of the transverse DC magnetic field, the arc is subjected to a constant Lorentz force and stably deflects to one side perpendicular to the direction of weld seam 7. This can realize the directional shift of the welding heat source and the asymmetric heat input distribution, effectively adjust the unilateral penetration depth and drive the directional flow of the molten pool. It is suitable for welding dissimilar materials, asymmetric bevel welding, single-sided corner joints, and unilateral welding in confined spaces. Under the influence of the transverse alternating magnetic field, the electric arc and the molten pool are subjected to periodic alternating Lorentz forces. On the one hand, the electric arc makes regular reciprocating transverse oscillations along the direction perpendicular to the weld seam 7. On the other hand, the liquid metal in the molten pool forms orderly convection from top to bottom along the direction perpendicular to the surface of the base material. This can evenly distribute the transverse heat input of the weld seam 7, widen the weld width and improve the sidewall fusion, and deeply agitate the molten pool, refine the grains, and promote the discharge of gas and slag. It is suitable for welding narrow-gap thick plates, light alloys and high-performance steels.

[0100] Figure 12 This is a schematic diagram of the force principle of the magnetically controlled arc and the molten pool when the spatial angle between the transverse alternating magnetic field on the welding torch side is equal to 90°, provided by an embodiment of the present invention. Figure 12 The diagram shows the welding torch, the electric arc, and the longitudinal section of weld 7. Since the spatial angle is 90°, the transverse magnetic field is perpendicular to the direction of weld 7. The left diagram shows the electric arc being deflected and stretched forward along the direction of weld 7 by the Lorentz force F, and the right diagram shows the electric arc being deflected and stretched backward by the Lorentz force F. The electric arc oscillates back and forth along the direction of weld 7, causing the molten metal in the molten pool to be stirred longitudinally back and forth.

[0101] Therefore, when the spatial angle is 90°, the transverse magnetic field direction is perpendicular to the weld seam 7 of the workpiece. When the welding power source is DC positive, the arc is subjected to a Lorentz force parallel to the direction of travel of the weld seam 7. When an auxiliary power source is connected to the workpiece 2 along the direction of the weld seam 7, the molten pool can be subjected to a Lorentz force perpendicular to the surface of the base material. Under the action of the transverse DC magnetic field, the arc is subjected to a constant Lorentz force, stably deflecting along the direction of the weld seam 7, which can improve the magnetic blow of the arc. Under the action of the transverse AC magnetic field, the arc is subjected to a periodic alternating Lorentz force, driving the arc to oscillate back and forth along the direction of the weld seam 7, causing the liquid metal in the molten pool to flow back and forth synchronously. Through longitudinal stirring and extending the existence time of the tail of the molten pool, common defects such as porosity, hot cracks, undercut, and humps are solved at the same time. It is especially suitable for high-speed welding and welding of thin plates and crack-sensitive materials.

[0102] Figure 13 This is a wiring diagram of a workpiece-side transverse magnetic field generating circuit provided in an embodiment of the present invention. Figure 13Only the tenth, twelfth, fourteenth, and sixteenth switches in the lower bridge arm switch group are in the closed conducting state, while the rest of the switches are open. The excitation current flows only through the two sets of excitation coils 4 below the workpiece side, while the two sets of coils above the welding gun side are in the de-energized state. Figure 14 This is a stereoscopic view of the transverse magnetic field space on the workpiece side provided in an embodiment of the present invention. Figure 14 The diagram shows that the magnetic pole above the welding torch is non-magnetic, the left magnetic pole below workpiece 2 is the S pole, and the right magnetic pole is the N pole. A stable horizontal DC magnetic field is generated at the bottom of workpiece 2, parallel to the direction of weld seam 7 along the surface of workpiece 2. This is the transverse magnetic field mode on the workpiece side. When the spatial angle is 0° and the tenth, twelfth, fourteenth, and sixteenth switches are turned on, the excitation circuit, after connecting the DC power supply, can generate a stable transverse DC magnetic field on the second magnetic pole 3 on the back of workpiece 2. The direction of the magnetic field is parallel to the direction of weld seam 7.

[0103] Figure 15 This is a cross-sectional schematic diagram of the force principle of a workpiece side transverse DC magnetic field magnetocontrolling molten pool lifting provided by an embodiment of the present invention. Figure 15 An auxiliary power supply is connected to workpiece 2 perpendicular to weld 7 to introduce a transverse conductive current. This transverse current interacts with a transverse magnetic field on the back of workpiece 2 that is parallel to the direction of weld 7. Figure 15 The arrow points inward, inducing a Lorentz force F perpendicularly upward towards the base material surface in the conductive molten metal at the bottom of the weld pool. This force counteracts the downward force of the molten pool due to its own weight. Therefore, by connecting an auxiliary power supply to the workpiece 2 in a direction perpendicular to the weld 7 and supplying an auxiliary current, the magnetic field can apply a Lorentz force perpendicular to the base material surface to the molten metal at the bottom of the weld 7. This effectively counteracts the downward force of the molten pool, stabilizing the weld pool's formation. This method is particularly suitable for wide-gap welding and welding of highly fluid metals such as aluminum alloys.

[0104] Figure 16 This is a wiring diagram of a longitudinal magnetic field generating circuit provided in an embodiment of the present invention. Figure 16 The first, third, sixth, eighth, tenth, thirteenth, fifteenth and seventeenth switches are simultaneously turned on, while the remaining switches are turned off, connecting all two sets of coils on the welding torch side and two sets of coils on the workpiece side into the circuit and forming a series circuit of the same polarity excitation. Figure 17 This is a three-dimensional perspective diagram of the spatial distribution of a longitudinal DC magnetic field provided in an embodiment of the present invention. Figure 17The two semi-annular magnetic poles above the welding torch are simultaneously excited as N poles, and the two semi-annular magnetic poles below the workpiece are simultaneously excited as S poles. This creates a uniform, parallel longitudinal magnetic field bundle that penetrates vertically from top to bottom through the workpiece 2 and the arc zone between the upper and lower pairs of magnetic poles. Therefore, when the first, third, sixth, eighth, tenth, thirteenth, fifteenth, and seventeenth switches are turned on, the excitation circuit generates a uniform longitudinal magnetic field that runs in the same direction as the arc axis.

[0105] Figure 18 This is a schematic diagram of the longitudinal DC magnetic field arc focusing and rotating convection magnetocontrol principle provided by an embodiment of the present invention. Figure 18 The left-hand front view section shows that under the influence of a vertically downward longitudinal magnetic field, the outer contour of the electric arc significantly contracts and converges towards the central axis, i.e., the arc compression effect. The right-hand top view section shows that charged particles in the arc plasma undergo high-speed circular spiral motion under the action of tangential Lorentz force as they diffuse radially outward, driving the molten pool metal to generate rotating convection stirring. Thus, during the radial diffusion process, charged particles in the arc undergo circular motion under the action of the magnetic field and are subjected to tangential Lorentz force. When DC excitation power is used, the longitudinal magnetic field direction is constant, driving the charged particles to move in a unidirectional circular motion. Relying on the centripetal force generated by the circular motion, the charged particles are gathered together, realizing arc compression and arc convergence. At the same time, the arc moves along the magnetic field lines in a spiral trajectory, driving the molten pool to rotate and stir synchronously in a unidirectional direction. This is suitable for deep penetration welding of thick plates and welding conditions where arc magnetic blow is prone to occur. Moreover, the larger the excitation current, the greater the magnetic induction intensity, the greater the Lorentz force on the arc, the smaller the spiral motion radius, and the higher the arc stiffness. When welding vertically, if the direction of the applied longitudinal magnetic field is parallel to the arc axis and points towards the workpiece 2, the molten droplets and molten pool metal will be subjected to an upward Lorentz force, which can counteract the influence of gravity and prevent the molten pool from flowing downward. When using AC excitation power supply, an axial alternating longitudinal magnetic field can be generated, causing the arc and molten pool to rotate alternately in opposite directions, realizing bidirectional uniform stirring of the molten pool. This can effectively improve the compositional segregation of weld 7 and refine the metallographic structure of weld 7, making it suitable for precision parts welding, dissimilar material welding, and welding scenarios with high requirements for the uniformity of weld 7 structure.

[0106] Figure 19 This is a wiring diagram of a horizontal and vertical composite magnetic field generating circuit provided in an embodiment of the present invention. Figure 19 The first, second, fourth, seventh, ninth, eleventh, fifteenth and seventeenth switches are simultaneously turned on, while the remaining switches are turned off, and the four sets of excitation coils 4 form a cross differential topology connection. Figure 20 This is a three-dimensional perspective diagram of the spatial distribution of a horizontal and vertical DC composite magnetic field provided in an embodiment of the present invention. Figure 20The magnetic poles above the welding torch side are N-pole on the left and S-pole on the right, while the magnetic poles below the workpiece side are S-pole on the left and N-pole on the right. Simultaneously, horizontally bridging magnetic lines and vertically penetrating magnetic lines are synthesized in the welding space, constructing a three-dimensional, inclined, intersecting spatial composite magnetic field distribution. Therefore, when the first, second, fourth, seventh, ninth, eleventh, fifteenth, and seventeenth switches are turned on, the excitation circuit is energized, synchronously generating the composite magnetic field that superimposes the horizontal and vertical forces. This causes the first magnetic pole 1 on the welding torch side and the second magnetic pole 3 on the workpiece side to form longitudinal magnetic field components in opposite directions. This causes the charged particles on both sides of the arc to experience the same Lorentz force, driving the arcs on both sides to rotate and shift synchronously in the same direction.

[0107] Figure 21 This is a cross-sectional schematic diagram of the principle of magnetic arc deflection and stiffness maintenance by a transverse and longitudinal DC composite magnetic field provided in an embodiment of the present invention. Figure 21 The diagram shows the arc deflecting at a stable large angle to a predetermined unilateral direction under the drive of the transverse magnetic field component, achieving asymmetric heat input. Simultaneously, the arc maintains axial contraction and rigidity under the constraint of the longitudinal magnetic field component. A top-down view on the right shows the charged particles in the micro-area maintaining stable helical spin under the combined electromagnetic force. Therefore, when the welding power source is DC reverse polarity, the arc deflection direction is consistent with the arc deflection direction under the transverse magnetic field. The superposition of these two factors significantly enhances the arc deflection effect. Simultaneously, the longitudinal magnetic field component compresses and contracts the arc, effectively improving its rigidity and stiffness. When using DC excitation power, both the transverse and longitudinal magnetic field directions remain constant, driving the arc to stably deflect to a unilateral direction perpendicular to the weld seam 7. When using AC excitation power, the transverse and longitudinal magnetic field directions change periodically, and the arc oscillates regularly under the Lorentz force. Depending on the size of the spatial angle, the spatial direction of arc deflection or oscillation varies, allowing for flexible application in different welding scenarios.

[0108] The automatic closed-loop intelligent control method described in the foregoing embodiments first involves synchronous acquisition of multi-source data. Specifically, for arc data acquisition, an arc vision sensing component is configured, such as a high-temperature resistant industrial camera mounted above the welding torch, equipped with an anti-glare filter and a spatter shield. The lens is aimed at the arc area to acquire image data such as the arc contour morphology and droplet transition. For molten pool data acquisition, a temperature acquisition component is configured, such as an infrared thermal imager installed at a 30° to 45° angle to the side of the welding torch, focusing on the molten pool area to acquire real-time molten pool temperature field distribution data, simultaneously capturing the size, shape, and flow trend of the molten pool, avoiding interference from heat radiation with temperature measurement accuracy. For welding data acquisition, a welding electrical parameter monitoring component is configured, such as a current sensor connected in series and a voltage sensor connected in parallel at the output of the main circuit of the welding power supply, to acquire real-time current and voltage data of the welding main circuit and simultaneously upload them to the data acquisition terminal for judging welding stability. For magnetic field data acquisition, a space magnetic field feedback component is configured, such as installing a Hall sensor near the working end face of the magnetic pole body to monitor the actual magnetic induction intensity, polarity direction and alternating frequency in real time. The feedback data is used for closed-loop control of magnetic field parameters to ensure that the magnetic field output is consistent with the decision command.

[0109] Then, data preprocessing is performed. Specifically, the collected raw multi-source data is filtered, denoised, and normalized to remove invalid data caused by welding spatter and strong light interference. Image data is converted to grayscale and enhanced to extract key features such as arc morphology and weld pool edges. Time-series data, such as welding current, welding voltage, and actual magnetic field parameters, are smoothed and filtered to eliminate high-frequency fluctuation interference, providing a high-quality data foundation for algorithm analysis.

[0110] Then, the algorithm model is selected and trained. Specifically, a fusion network model, such as a fusion model of convolutional neural networks and long short-term memory (LSTM) temporal networks, is selected. The convolutional neural network is used to identify the spatial features of the working conditions in the arc image and the molten pool temperature field image, such as the bevel geometry, assembly gap size, and molten pool contour state. The LSTM temporal network is used to analyze the temporal variation patterns of welding current, welding voltage, and magnetic field parameters, achieving dynamic identification of complex working conditions. The model is trained based on experimental data of different welding materials, such as high-strength steel and aluminum alloys, bevel shapes, and assembly gaps. The model parameters are optimized to ensure that the accuracy of dynamic identification of working conditions reaches the preset target, such as an accuracy rate of not less than 95%. Then, intelligent decision-making logic is established. Specifically, based on the trained algorithm model, an intelligent decision-making algorithm is developed, and an adaptive mapping relationship rule base from working condition features to magnetic field parameters is established.

[0111] Finally, the intelligent magnetic welding closed-loop control is executed. Specifically, the system automatically identifies changes in working conditions such as bevel geometry, heat dissipation conditions, and assembly gaps online, and makes real-time decisions on the target magnetic field mode, magnetic induction intensity, direction of action, and alternating frequency. It then issues control commands to drive the polarity reconfiguration switch matrix and adjust the excitation power output, thus completing the fully automatic closed-loop intelligent control of the arc and molten pool states.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-modal composite magnetic field intelligent magnetron welding system, characterized in that, include: A magnetic pole assembly includes two magnetic poles, the two magnetic poles including a first magnetic pole arranged on the welding torch side of the welding area, and a second magnetic pole arranged on the workpiece side away from the welding torch; An external excitation assembly includes multiple excitation coils disposed in a protective zone; wherein the distance from the protective zone to the welding zone is greater than or equal to a first distance; Multiple flexible magnetic conductor wire bundles, with each flexible magnetic conductor wire bundle having its two ends connected to the corresponding excitation coil and the magnetic conductor pole respectively, for transmitting the magnetic flux generated by the excitation coil to the corresponding magnetic conductor pole; A polarity reconfiguration switch matrix is ​​electrically connected between the excitation power supply and each of the excitation coils. It is used to reconfigure the circuit on / off state and current flow direction of each of the excitation coils according to control commands, so as to excite at least one of the transverse magnetic field mode, longitudinal magnetic field mode or transverse-longitudinal composite magnetic field mode in the welding area.

2. The multi-modal composite magnetic field intelligent magnetron welding system according to claim 1, characterized in that, The first magnetic pole body is mounted on the neck of the welding torch by a rotating clamp. The rotating clamp is used to adjust the spatial angle between the line connecting the geometric centers of the two semi-annular magnetic pole bodies in the first magnetic pole body and the direction of the weld seam on the workpiece. in ； The adjustable range of the spatial angle is 0° to 90°; The second magnetic pole is disposed on the follower mechanism, which is used to drive the second magnetic pole to maintain a spatial relative position lock with the first magnetic pole during the welding process.

3. The multi-modal composite magnetic field intelligent magnetron welding system according to claim 1, characterized in that, The flexible magnetic conductor bundle is made of multiple strands of mutually insulated magnetic conductors twisted together. The outer periphery of the flexible magnetic conductor bundle is covered with an insulating protective layer. The permeability of the flexible magnetic conductor bundle is matched with that of the magnetic pole body.

4. The multi-modal composite magnetic field intelligent magnetron welding system according to claim 1, characterized in that, The magnetic flux docking end of the magnetic pole body is provided with a mating groove that gradually narrows from the groove opening to the groove bottom, and the end of the flexible magnetic wire bundle is formed into a wedge-shaped end that matches the slope of the mating groove. A magnetic dielectric layer is provided between the wedge-shaped end and the mating surface of the mating groove; and / or, a non-magnetic insulating limiting member is provided at the opening of the mating groove to mechanically lock the wedge-shaped end.

5. The multi-mode composite magnetic field intelligent magnetron welding system according to any one of claims 1-4, characterized in that, The first magnetic pole body includes a first semi-annular magnetic pole body and a second semi-annular magnetic pole body, the second magnetic pole body includes a third semi-annular magnetic pole body and a fourth semi-annular magnetic pole body, and the external excitation assembly includes four sets of excitation coils respectively connected to the first semi-annular magnetic pole body to the fourth semi-annular magnetic pole body. The polarity reconfiguration switch matrix is ​​electrically connected between the excitation power supply and the four sets of excitation coils, and includes at least one of the following switch groups: Upper bridge arm switch assembly used to construct a horizontal transverse magnetic field on the welding torch side; Lower bridge arm switch assembly used to construct the transverse magnetic field on the workpiece side; Interlayer switching groups are used to construct axially continuous longitudinal magnetic fields or three-dimensional intersecting transverse and longitudinal composite magnetic fields.

6. The multi-modal composite magnetic field intelligent magnetron welding system according to claim 5, characterized in that, The first lead end of the first semi-annular magnetic pole is electrically connected to the first switch, and the second lead end is electrically connected to the second switch and the third switch; The first lead of the second semi-annular magnetic pole is electrically connected to the fourth to sixth switches, and the second lead is electrically connected to the seventh and eighth switches. The first lead of the third semi-annular magnetic pole is electrically connected to the ninth and tenth switches, and the second lead is electrically connected to the eleventh to thirteenth switches. The first lead of the fourth semi-annular magnetic pole is electrically connected to the fourteenth and fifteenth switches, and the second lead is electrically connected to the sixteenth to seventeenth switches.

7. The multi-mode composite magnetic field intelligent magnetron welding system according to any one of claims 1-4, characterized in that, It also includes at least one of the following components: An arc vision sensing component, positioned toward the welding arc, is used to acquire images of the arc profile and / or droplet transfer. The temperature acquisition component is positioned towards the weld pool and is used to collect temperature field data of the weld pool. The welding electrical parameter monitoring component is electrically connected to the output terminal of the main circuit of the welding power supply and is used to collect the current and / or voltage signals of the main welding circuit. A spatial magnetic field feedback component is attached to the working end face of the first magnetic pole and / or the second magnetic pole to collect at least one parameter among the magnetic field strength, polarity direction and alternating frequency of the arc region.

8. A multi-modal composite magnetic field intelligent magnetron welding control method, characterized in that, The method for controlling the multimodal composite magnetic field intelligent magnetron welding system as described in any one of claims 1-7 includes: Obtain the target magnetic field mode corresponding to the target welding condition; The polarity reconfiguration switch matrix is ​​controlled to switch to the loop connection topology corresponding to the target magnetic field mode, and the excitation power supply is controlled to output excitation current to the excitation coil. The excitation current excites the excitation coil to generate magnetic flux, which is conducted to the first and second magnetic poles via the flexible magnetic wire bundle, and excites at least one of the transverse magnetic field mode, longitudinal magnetic field mode, or transverse-longitudinal composite magnetic field mode in the welding area.

9. The intelligent magnetic control welding method with multi-modal composite magnetic field according to claim 8, characterized in that, Excite at least one of the following in the welding zone: a transverse magnetic field mode, a longitudinal magnetic field mode, or a combined transverse and longitudinal magnetic field mode: An alternating excitation current is passed through the two excitation coils on the welding torch side, causing the first magnetic pole body to generate a transverse magnetic field with periodic polarity reversal; wherein, when the spatial angle between the line connecting the geometric centers of the two semi-annular magnetic pole bodies in the first magnetic pole body and the weld seam direction of the workpiece is equal to 0°, the electric arc is driven to oscillate back and forth along the perpendicular weld seam direction; when the spatial angle is equal to 90°, the electric arc is driven to oscillate back and forth along the weld seam direction. A DC excitation current is passed through the two excitation coils on the workpiece side, causing the second magnetic pole to generate a transverse magnetic field parallel to the weld direction, and an auxiliary current is applied to the workpiece in the direction perpendicular to the weld, inducing an upward electromagnetic force at the bottom of the molten pool. The first magnetic pole body is controlled to be excited in phase with the first polarity and the second magnetic pole body is controlled to be excited in phase with the second polarity. A longitudinal magnetic field that runs through the arc axis is constructed in the welding area, driving the charged particles of the arc to make centripetal spiral motion to compress the arc and drive the molten pool to rotate and convection. The control polarity reconfiguration switch matrix forms a cross differential connection topology, which simultaneously excites the transverse magnetic field component and the longitudinal magnetic field component in the welding area. The transverse magnetic field component is used to drive the arc to deflect to a preset single side, and the longitudinal magnetic field component is used to maintain the axial convergence of the arc.

10. The intelligent magnetic control method for multi-modal composite magnetic field welding according to claim 8 or 9, characterized in that, Also includes: Obtain multi-source sensing parameters during the welding process; wherein, the multi-source sensing parameters include arc images, molten pool temperature field data, welding main circuit electrical parameters, and actual magnetic field parameters; The multi-source sensing parameters are subjected to feature extraction and fusion analysis to obtain working condition features; wherein, the working condition features include bevel geometry, assembly gap size, heat dissipation symmetry of the base material, and droplet transition stability; The target magnetic field mode and the excitation parameters of the excitation coil are dynamically adjusted according to the operating conditions.

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