An Adaptive Regulation Device for the Sag Defect in Electromagnetic Field Assisted Laser-Arc Hybrid Welding

Abstract

The present invention discloses an adaptive control device for the undercut defect in electromagnetic field-assisted laser-arc hybrid welding. The magnetic poles of the magnetic field assembly are arranged on the upper surface of the box body carrying the magnetic field assembly, and the air outlet of the air duct is arranged at the gap between the magnetic poles. The air outlet is aligned with the bottom of the weld seam in the vertical direction, so that the air blown out from the air outlet is guided from the bottom of the weld metal molten pool to both sides to form a lateral wind; the air duct is connected to a high-pressure air source; the gap between the upper surface of the box body on both sides of the magnetic poles and the welded base material forms the air duct of the lateral wind; the bottom of the box body supports a second spring; lifting components are symmetrically arranged on both sides of the magnetic poles. The lifting component includes a wind pressure transmission mechanism arranged horizontally in the transverse direction and a mechanical transmission mechanism that drives the magnetic poles to lift vertically by the transverse movement of the wind pressure transmission mechanism; the wind pressure transmission mechanisms of the two lifting components are collinear in the transverse direction. The present invention reflects the wind pressure on the lifting of the magnetic poles, adjusts the distance between the magnetic poles and the weld seam, and further adjusts the magnitude of the Lorentz force of the magnetic poles on the weld molten pool.

Description

Technical Field

[0001] The present invention belongs to the technical field of welding, and particularly relates to an adaptive regulation device for undercut defects in electromagnetic field-assisted laser-arc hybrid welding. Background Art

[0002] Welding is an indispensable processing technology in modern manufacturing, and is widely used in fields such as aerospace, automotive manufacturing, shipbuilding industry, and energy equipment. Traditional welding methods include arc welding and laser welding. Arc welding generates high temperature through an arc to melt the base material and filler material, and has the advantages of low equipment cost and wide applicability, but has problems such as large heat input, large welding deformation, and slow welding speed; laser welding uses a high-energy laser beam to melt materials, and has the advantages of high energy density, fast welding speed, and small heat affected zone, but has high requirements for the assembly accuracy of workpieces and is difficult to weld high-reflectivity materials. In order to overcome the limitations of a single welding method, the laser-arc hybrid welding technology has emerged. This technology uses both a laser beam and an arc as heat sources at the same time. The laser beam provides a high energy density, and the arc provides a larger penetration depth and filler material. The two interact with each other to form a stable hybrid heat source.

[0003] In recent years, with the entry of multi-kilowatt lasers into the market, the penetration depth of single-sided laser-arc hybrid welding with double-sided formation has been further increased. With the increase in the thickness of the welded plate, defects such as spatter, porosity, undercut, and undercut often appear. Among them, the undercut defect in the weld is even more difficult to eliminate in thick plate welding, seriously affecting the performance and life of the joint.

[0004] In laser-arc hybrid welding, the dual heat sources cause the melting, vaporization, and plasmaization of the welded base material. The molten metal is affected by the recoil pressure of the vapor, arc pressure, self-gravity, etc. It has been found that the imbalance between the gravity of the molten pool and the bottom tension is the main cause of the undercut at the bottom of the weld. The existing main regulation methods for weld undercut are still through external support, backing welding, etc. Although they can effectively control the formation of weld undercut, they put higher requirements on the welding processing environment, processing cycle, and production cost.

[0005] In the academic paper "PA position full penetration high-power laser beam welding of up to 30 mm thick AlMg3 plates using electromagnetic weld pool support" written by German scholar V. V. Avilov, a technical solution was published for the above problem. In this solution, an oscillating electromagnetic field is added below the molten pool at the weld of the base metal to provide an upward Lorentz force to the molten metal at the bottom of the weld. This support force slows down the process of the molten metal flowing downward and inhibits the formation of the collapse at the bottom of the weld. However, when implementing this solution, it is easy for the molten pool to be subjected to too much or too little force due to the change of the magnetic field strength, resulting in the convex or concave shape of the finally formed weld, seriously affecting the quality of the base metal for welding. Therefore, an external mechanism needs to be installed to adjust the magnitude of the Lorentz force received by the molten pool of the base metal for welding. For this problem, several technical solutions have been disclosed:

[0006] Chinese Patent with application number 201811033087.7 discloses an on-line detection method and device for laser welding hump defects. This device collects pictures by installing a high-speed camera on the side of the base metal for welding, analyzes the pictures and feeds back the results to the motion control unit to change the position of the laser focus to achieve the suppression of the collapse at the bottom of the weld. However, the feedback system of this invention has high requirements for the precision of the high-speed camera, and the camera itself is easily affected by the strong light generated during welding, resulting in low reliability.

[0007] Chinese Patent with application number 201920521500.8 discloses an electromagnetic field-assisted laser welding device. This device places the workpiece between two permanent magnets and clamps it, and provides current to the molten pool through a current generator. The current flows through the static magnetic field range of the permanent magnets to generate a stable electromagnetic force, thereby ensuring the quality of the weld formation.

[0008] Chinese Patent with application number 202210924200.0 discloses a magnetic field-assisted laser welding platform based on magnetic field pattern simulation design. This platform consists of a magnetic field generating device and a welding fixture. An alternating magnetic field concentrated below the weld is generated by winding coils around the surface of silicon steel sheets, thereby optimizing the welding quality. Through simulation, it is obtained that when the distance between the iron core and the lower surface of the base metal for welding decreases, the magnetic field strength at the center of the weld increases.

[0009] The above technical solution can already use an alternating magnetic field to avoid the formation of undercut at the bottom of the weld, and can even achieve the effect of concave-up at the bottom of the weld. However, the regulation of the undercut effect is mainly achieved by adjusting process parameters or the input power of the alternating magnetic field, and the adjustment methods are all manual adjustments, with limited accuracy, and the Lorentz force on the molten metal at the weld cannot be automatically adjusted by a pure mechanical method. Summary of the Invention

[0010] In view of the above problems, the present invention proposes an adaptive regulation device for undercut defects in electromagnetic field-assisted laser-arc hybrid welding.

[0011] The present invention blows air towards the lower end of the weld pool, and uses a wind baffle to withstand the lateral wind guided by the lower end of the weld pool. The change in the shape of the lower end of the weld pool causes a change in the wind direction of the lateral wind, and the wind pressure on the wind baffle changes accordingly. In this way, the shape information of the lower end of the weld pool is collected. The present invention converts the wind pressure on the wind baffle into a vertical force acting on the magnetic field component where the magnetic pole is located through a lifting component, thereby realizing the adaptive adjustment of the Lorentz force and finally eliminating the undercut defect at the bottom of the weld.

[0012] The technical solution adopted by the present invention is as follows:

[0013] An adaptive regulation device for undercut defects in electromagnetic field-assisted laser-arc hybrid welding, including a magnetic field component arranged on a welding tooling platform. The magnetic pole of the magnetic field component is close to the weld of the welded base material, and applies a Lorentz force to the bottom of the weld pool to inhibit undercut of the weld. Assume that the welded base material is placed horizontally and the weld is arranged longitudinally. In the horizontal plane, the direction perpendicular to the weld is the transverse direction, and the side close to the weld in the transverse direction is the inner side.

[0014] The magnetic pole of the magnetic field component is arranged on the upper surface of the box body carrying the magnetic field component, and the air outlet of the air duct is arranged in the gap between the magnetic poles; the air outlet is aligned with the bottom of the weld from the vertical direction, so that the air blown out from the air outlet is guided to both sides through the bottom of the weld metal pool, forming a lateral wind; the air duct is connected to a high-pressure air source.

[0015] The gap between the upper surface of the box body on both sides of the magnetic pole and the welded base material forms the air duct of the lateral wind.

[0016] The bottom of the box body supports a second spring.

[0017] Lifting components are symmetrically arranged on both sides of the magnetic pole. The lifting component includes a wind pressure transmission mechanism arranged horizontally in the transverse direction and a mechanical transmission mechanism that drives the vertical lifting of the magnetic pole by the transverse movement of the wind pressure transmission mechanism; the wind pressure transmission mechanisms of the two lifting components are collinear in the transverse direction.

[0018] The wind pressure transmission mechanism includes a wind deflector which is arranged at the bottom of the air duct and faces the magnetic pole. The outer side of the wind deflector is connected with an upper wedge block. The inclined surface of the upper wedge block faces downward, with the inner side being higher and the outer side being lower. The upper wedge block is connected with a first spring pre-tightened inward. The upper wedge block and the lower wedge block are mutually attached through inclined surfaces and are slidably connected to each other.

[0019] One end of the mechanical transmission mechanism is connected with the lower wedge block, and the other end is connected with the box body carrying the magnetic field assembly, converting the vertical movement of the lower wedge block into the vertical movement of the magnetic pole assembly.

[0020] Preferably, the wind deflector is arranged at the lower part of the air duct.

[0021] Preferably, the upper wedge block is connected with the wind deflector through an upper transmission bracket.

[0022] Preferably, in the mechanical transmission mechanism, a vertical connecting rod is arranged on a vertical guide rail. The upper end of the vertical connecting rod is connected with the bottom of the lower wedge block, and the pin at the lower end is inserted into the axial long hole at one end of an adjusting connecting rod. The pin at the other end of the adjusting connecting rod is inserted into the transverse long hole of a fixed angle piece, and the fixed angle piece is fixedly installed on the box body. The middle part of the adjusting connecting rod is hinged on a lower fixed bracket.

[0023] Furthermore, a number of adjusting through holes are provided in the middle part of the adjusting connecting rod to change the relative positions of the lower fixed bracket and the adjusting bracket, and adjust the lifting ratio of the magnetic field assembly.

[0024] Alternatively, in the mechanical transmission mechanism, a vertical connecting rod is arranged on a vertical guide rail. The upper end of the vertical connecting rod is fixedly installed at the bottom of the lower wedge block. A first rack is arranged on the inner side of the vertical connecting rod. The first rack meshes with a gear, and the other side of the gear meshes with a second rack on the side of the box body.

[0025] Alternatively, in the mechanical transmission mechanism, the upper end of a first piston rod is fixedly installed at the bottom of the lower wedge block. The lower end of the first piston rod is located in a first hydraulic cylinder. The first hydraulic cylinder and a second hydraulic cylinder are connected through a hydraulic pipe. The lower end of a second piston rod is located in the second hydraulic cylinder, and the upper end of the second piston rod is fixedly connected with a fixing piece on the side of the box body.

[0026] Preferably, the vertical guide rail is an upper fixed bracket with one end fixed on the box body. The other end of the upper fixed bracket has a guiding hole for the vertical connecting rod to pass through, restricting the vertical connecting rod to move only in the vertical direction.

[0027] Preferably, the included angle between the wind deflector and the horizontal plane is 60°, and a number of ventilation holes are provided on the wind deflector.

[0028] Preferably, the lower end of the air outlet is an isosceles trapezoid structure with a narrower upper part and a wider lower part to increase the air flow velocity; the magnetic pole has a convex shape near the air outlet to change the air flow direction.

[0029] Further, in the magnetic pole assembly, the U-shaped iron core is arranged inside the box body through a fixed platform, and excitation coils are sleeved on the bottom and the lateral sides of the U-shaped iron core.

[0030] The mechanism of the present invention is as follows: During use, the air flow enters the air duct through the air flow interface and is ejected from the air outlet, blowing towards the bottom of the metal molten pool of the weld seam. The air blown out from the air outlet is guided to both sides through the bottom of the weld seam, forming a lateral air flow. The change in the shape of the bottom of the metal molten pool causes a change in the lateral air flow direction, thereby increasing or decreasing the wind pressure on the wind deflector in the lifting assembly. The present invention reflects this wind pressure on the lifting of the magnetic pole, adjusts the distance between the magnetic pole and the weld seam, and further adjusts the magnitude of the Lorentz force of the magnetic pole on the weld seam molten pool.

[0031] The working principle of the present invention is:

[0032] When the bottom of the weld seam is flat (before welding starts), adjust the elastic force of the first spring connected to the outside of the wind deflector so that the wind pressure on the wind deflector is balanced with the pulling force of the first spring, and the lifting assembly reaches the equilibrium position. After calibrating the lifting assembly, then put the present invention into use.

[0033] During use, when the magnetic pole is too far away from the weld seam, the Lorentz force provided by it is not enough to overcome the downward fall of the metal in the weld seam molten pool, causing the bottom of the weld seam to sag and the bottom of the weld seam to bulge. The lateral air flow is guided to the upper edge of the air duct, that is, the air flow is lifted upwards and away from the wind deflector. Therefore, the wind pressure on the wind deflector decreases, breaking the balance between the wind pressure on the wind deflector and the pulling force of the first spring. The first spring pulls the upper wedge block and the wind deflector inward. During this process, the lower wedge block is pressed down, driving the mechanical transmission mechanism to lift the box body, making the magnetic pole approach the weld seam, increasing the Lorentz force of the magnetic pole on the weld seam molten pool, and correcting the convexity of the weld seam molten pool.

[0034] When the magnetic pole is too close to the weld seam, the Lorentz force acting on the weld seam molten pool is too large, causing the weld seam molten pool to bulge and the bottom of the weld seam molten pool to be concave. The lateral air flow is guided to the lower edge of the air duct, and the wind pressure on the wind deflector increases, breaking the balance between the wind pressure on the wind deflector and the pulling force of the first spring. The wind deflector pushes the upper wedge block and the wind deflector outward. During this process, the lower wedge block is lifted, driving the mechanical transmission mechanism to press down the box body, making the magnetic pole away from the weld seam, reducing the Lorentz force of the magnetic pole on the weld seam molten pool, and correcting the concavity of the weld seam molten pool.

[0035] The lifting assembly of the present invention swings multiple times between the positions where the Lorentz force is too large and too small, and finally automatically reaches the equilibrium position. At this time, the bottom of the weld seam does not sag and does not bulge.

[0036] The advantages of the present invention are:

[0037] 1. It can automatically adjust the magnitude of the Lorentz force acting on the weld pool to achieve a flat weld and avoid weld collapse.

[0038] 2. The present invention is portable and flexible, with a simple operation of the adjustment system, capable of achieving high-precision weld control, adapting to the actual needs of industrial production, and having a wide application prospect.

[0039] 3. During the welding process, the device of the present invention performs adaptive adjustment in a purely mechanical manner, automatically raising and lowering the height of the magnetic field component to eliminate the weld bottom collapse defect, ensuring high reliability while guaranteeing precision.

[0040] 4. The lifting ratio of the magnetic field component in the present invention is adjustable, suitable for a variety of materials, and applicable to a large process range, which can greatly reduce the previous debugging work. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a schematic structural diagram of the adaptive control device for the collapse defect in arc composite welding of the present invention.

[0042] Figure 2 is a schematic structural diagram of another perspective of the adaptive control device for the collapse defect in arc composite welding provided by the present invention.

[0043] Figure 3 is a schematic structural diagram of the lifting component of the adaptive control device for the collapse defect in arc composite welding of the present invention.

[0044] Figure 4a is a schematic structural diagram of the mechanical transmission mechanism in Embodiment 1 of the present invention.

[0045] Figure 4b is a schematic structural diagram of the mechanical transmission mechanism in Embodiment 2 of the present invention.

[0046] Figure 4c is a schematic structural diagram of the mechanical transmission mechanism in Embodiment 3 of the present invention.

[0047] Figure 5a 、 Figure 5b and Figure 5c are respectively the working principle diagrams of the lifting component of the present invention feeding back airflows in different directions through different weld morphologies (i.e., flat weld bottom, convex weld, concave weld).

[0048] Figure 6a 、 Figure 6b 、 Figure 6c and Figure 6d are respectively the adaptive control flowcharts of the present invention for the distance between the magnetic pole and the welded base material in different welding situations (i.e., before welding, concave weld, convex weld, good weld).

[0049] Figure 7 It is a schematic diagram of the local structure at the magnetic pole of the magnetic field component of the present invention.

[0050] Figure 8 It is a schematic diagram of the local details at the wind deflector of the lifting component of the present invention.

[0051] Figure 9 It is the weld cross-section corresponding to the one-side welding with both sides formed by high-power laser-arc hybrid welding of 6061 aluminum alloy constructed by the present invention without using electromagnetic field assistance.

[0052] Figure 10 It is the weld cross-section corresponding to the one-side welding with both sides formed by high-power laser-arc hybrid welding of 6061 aluminum alloy constructed by the present invention using electromagnetic field assistance. Specific embodiments

[0053] The following further describes the present invention in detail with reference to the drawings and embodiments. It should be noted that the following embodiments are intended to facilitate the understanding of the present invention and do not limit it.

[0054] Embodiment 1

[0055] Refer to Figure 1 , Figure 2 , Figure 3 , Figure 4a , Figure 7 and Figure 8 , an adaptive regulation device for the undercut defect in electromagnetic field-assisted laser-arc hybrid welding of the present invention includes a magnetic field component 5 arranged on a welding tooling platform 8. The magnetic pole 53 of the magnetic field component 5 is close to the weld of the welded base material 3 and applies a Lorentz force to the bottom of the weld pool to suppress the undercut of the weld. Assume that the welded base material 3 is horizontally placed, the weld is longitudinally arranged, the direction perpendicular to the weld in the horizontal plane is the transverse direction, and the side close to the weld in the transverse direction is the inner side.

[0056] The magnetic pole 53 of the magnetic field component 5 is arranged on the upper surface of the box body 4 carrying the magnetic field component 5, and the air outlet 617 of the air duct 616 is arranged at the gap of the magnetic pole 53; the air outlet 616 is aligned with the bottom of the weld from the vertical direction, so that the air blown out from the air outlet 617 is guided to both sides through the bottom of the weld metal pool to form a lateral wind; the air duct 616 is connected to a high-pressure air source.

[0057] The gap between the upper surface of the box body 4 on both sides of the magnetic pole 53 and the welded base material 3 forms the air duct of the lateral wind.

[0058] The bottom of the box body 4 supports the second spring 627a.

[0059] Lifting components 6 are symmetrically arranged on both sides of the magnetic pole 53. The lifting component 6 includes a wind pressure transmission mechanism 61 arranged horizontally and a mechanical transmission mechanism 62 that drives the magnetic pole assembly 5 to vertically lift and lower with the horizontal movement of the wind pressure transmission mechanism 61. The wind pressure transmission mechanisms 61 of the two lifting components 6 are collinear horizontally.

[0060] The wind pressure transmission mechanism 61 includes a wind baffle 611. The wind baffle 611 is arranged in the air duct and faces the magnetic pole on the inner side. The outer side of the wind baffle 611 is connected to an upper wedge block 612. The inclined surface of the upper wedge block 612 faces downward, with the inner side higher and the outer side lower. The upper wedge block 612 is connected with a first spring 613 that is pre-tightened inward. The upper wedge block 612 and the lower wedge block 614 are mutually attached through inclined surfaces. The angle between the inclined surface and the horizontal direction is 30°, and they are slidably connected to each other.

[0061] One end of the mechanical transmission mechanism 62 is connected to the lower wedge block 614, and the other end is connected to the box body 4 that bears the magnetic field assembly 5, converting the vertical movement of the lower wedge block 614 into the vertical movement of the magnetic pole assembly 5.

[0062] In this embodiment, the wind baffle 611 is arranged at the lower part of the air duct.

[0063] In this embodiment, in the mechanical transmission mechanism 62, a vertical connecting rod 621a is arranged on a vertical guide rail 622. The upper end of the vertical connecting rod 621a is connected to the bottom of the lower wedge block 614, and the pin at the lower end is inserted into the axial long hole at one end of an adjusting connecting rod 623a. The pin at the other end of the adjusting connecting rod 623a is inserted into the transverse long hole of a fixed angle member 624a. The fixed angle member 624a is fixedly installed on the box body 4, and the middle part of the adjusting connecting rod 623a is hinged to a lower fixed bracket 625a.

[0064] In this embodiment, a plurality of adjusting through holes 626a are provided in the middle part of the adjusting connecting rod 623a to change the relative positions of the lower fixed bracket 625a and the adjusting bracket 623a, and to adjust the lifting ratio of the magnetic field assembly 5.

[0065] Specifically, in this embodiment, the lifting amplitude is changed by adjusting the position of the fulcrum where the adjusting bracket 623a and the lower fixed bracket 625a are connected: when the fulcrum position is close to the lower transmission bracket 625a, the lifting amplitude is larger; when the fulcrum position is close to the fixed angle member 624a, the lifting amplitude is smaller. This measure can change the lifting ratio of the magnetic field assembly 5 during the welding process, and can precisely control the bottom collapse of the weld seam for different welding materials and different welding process parameters.

[0066] In this embodiment, the vertical guide rail 622 is an upper fixed bracket with one end fixed to the box body 4. The other end of the upper fixed bracket has a guiding hole for the vertical connecting rod 621a to pass through, restricting the vertical connecting rod 621a to move only in the vertical direction.

[0067] In this embodiment, the width of the windshield 611 is the same as that of the magnetic pole 53, which is 36 mm, the thickness is 1 mm, and the vertical height is 2 mm. Through simulation calculation, the pressure of the air flow on the windshield 611 is the largest when the included angle between the windshield 611 and the horizontal plane is 60°; in order to increase the pressure difference at both ends of the windshield 611 when it needs to move, 3×8 uniformly arranged ventilation holes are designed on the inclined plane where the windshield 611 is inclined at 60° to the horizontal plane. It is found by simulation that the ventilation holes with smaller diameters can form a region with lower pressure behind them under the condition of high gas flow velocity, so as to increase the wind pressure received by the windshield 611, where the diameter of the ventilation holes is 1 mm, and the distance between the centers of each ventilation hole is 8 mm.

[0068] In this embodiment, the lower end of the air outlet 617 is an isosceles trapezoid structure with a narrow upper part and a wide lower part to increase the air flow velocity; the magnetic pole 53 has a convex shape near the air outlet to change the air flow direction.

[0069] Specifically, ceramic windshields 615 are added to the front and back sides of the air outlet 617, which can effectively increase the flow velocity of the ejected air flow, and thus increase the pressure on the upper windshield. The shape of the bottom of the air outlet 617 is the same as that of the air outlet of the air duct 616, which is a circle with a diameter of 24 mm. The magnetic pole 53 is located at the two ports of the U-shaped iron core 51. The maximum convex height of the convex shape of the magnetic pole 53 is 3 mm, the arc radius of the convex end is 2 mm, and the angle between the inclined part and the horizontal direction is 30°. This structural setting can increase the flow velocity of the shielding gas blown towards the windshield 611, and can also effectively increase the Lorentz force received at the bottom of the molten pool.

[0070] More specifically, the diameter of the air duct 616 is 28 mm. The air outlet is bonded to the ceramic windshield 615 and the magnetic pole to reduce the leakage of the shielding gas to other directions. In order to avoid oxidation by air, the gas flowing in the air duct 616 is argon, and the gas flow velocity is 50 L / min. Argon can play a role in protecting the back weld, and at the same time, the upward blown air flow will also provide an upward supporting force for the bottom of the molten pool during the welding process, inhibiting the formation of weld collapse defects.

[0071] In this embodiment, in the magnetic pole assembly 5, the U-shaped iron core 51 is arranged inside the box body 4 through the fixed platform 52, and excitation coils 54 are sleeved on the bottom and the horizontal sides of the U-shaped iron core 51. The box body 4 is provided with an excitation power supply interface 41 and an air pipe interface 42, wherein the excitation power supply interface 41 is electrically connected to the excitation coil 54, and the air pipe interface 42 is connected to the air duct 616.

[0072] In this embodiment, the distance between the magnetic pole 53 of the U-shaped iron core 51 and the lower surface of the welding base material 3 before adjustment is 4 mm, and the adjustable range is 4 mm to 10 mm.

[0073] In this embodiment, the first spring 613 is used to buffer the thrust of the wind pressure transmission mechanism 61 on the upper wedge 612 during operation. Due to the thrust of the wind pressure transmission mechanism 61, the upper wedge 612 will move horizontally outward, but when the thrust decreases, it can rely on the pulling force generated by the deformation of the first spring 613 to move inward. The second spring 627a is used to support the gravity of the magnetic field assembly 5 and the box body 4. The downward gravity of the box body 4 during operation is affected by the acting force of the lifting assembly 6. By precisely designing the stiffness of the second spring 627a, the accurate matching between the acting force of the lifting assembly 6 and the height of the magnetic field assembly 5 can be achieved. The lifting distance of the magnetic field assembly 5 is related to the deformation coefficient of the second spring 627a, and the upward pulling force provided by the fixed angle member can be precisely converted into the displacement of the magnetic field assembly in the vertical direction.

[0074] Specifically, the first spring 613 and the second spring 627a are selected as different cylindrical helical springs. The first spring 613 has a smaller stiffness, its preloading force is 0 N, the free length is 60 mm, the load range is 0 N to 5 N, the outer diameter of the first spring is 10 mm, and the stiffness is selected as 0.1 N / mm. The weight of the magnetic field assembly 5 and the box body 4 is about 5 kg. Considering the external forces brought by the rise and fall of the magnetic field assembly 5, the preloading force of each second spring 627a is designed to be 12.5 N, the free length is 40 mm, the load range is 12.5 N to 18 N, the outer diameter value is 20 mm, and considering different application requirements, the stiffness range can be selected as 0.8 - 1.2 N / mm.

[0075] In this embodiment, the welding tooling platform 8 includes four vertical support brackets 83. The support brackets 83 are divided into two groups, and the support brackets 83 in each group are connected to each other by two transverse connecting rods 81, one above the other. A transmission roller 84 is provided in the middle of the connecting rod 81, and a gap allowing the external welding base material 3 to pass through is left between the transmission rollers 84 adjacent to each other vertically. A transmission motor 82 is provided on the support bracket 83. The transmission motor 82 is drivingly connected to the connecting rod 81 and can drive the transmission roller 84 to longitudinally transport the welding base material 3. The external welding torch 1 and the laser head 2 are aligned with the weld of the welding base material 3. In this embodiment, the brackets and connectors of the lifting assembly 6 and the welding tooling platform 8 are made of aluminum alloy materials, the ceramic windshield is made of high-temperature resistant ceramic sheets, the magnetic poles are made of iron-based amorphous alloy materials, and the box body is made of POM materials. In this embodiment, the end face of the U-shaped iron core 51 is 36 mm × 36 mm, symmetrically arranged left and right along the magnetic pole gap, the overall width is 258 mm, the height is 218 mm, the radius of the outer curved part is 56 mm, the horizontal distance between the two end magnetic poles is 10 mm, and the center of the magnetic pole is directly opposite to the weld position, and a concentrated strong alternating magnetic field can be generated at the lower end of the weld.

[0076] Example 2

[0077] Reference Figure 4b In this embodiment, in the mechanical transmission mechanism, the vertical connecting rod 621a is arranged on the vertical guide rail 622. The upper end of the vertical connecting rod 621a is fixedly installed at the bottom of the lower wedge block 614. A first rack 622b is arranged inside the vertical connecting rod 621a. The first rack 622b meshes with the gear 623b. The gear 623b meshes with the second rack 625b on the side of the box body 4. The center of the gear 623b is hinged to the lower fixed bracket 624b.

[0078] The remaining implementation manners are the same as those in Embodiment 1.

[0079] Example 3

[0080] Reference Figure 4c In this embodiment, in the mechanical transmission mechanism, the first piston rod 621c is arranged in the first hydraulic cylinder 622c. The upper end of the first piston rod 621c is fixedly installed at the bottom of the lower wedge block 614. The first hydraulic cylinder 622c is connected to the second hydraulic cylinder 625c through a hydraulic pipe 624c. The second piston rod 626c is arranged in the second hydraulic cylinder 625c and the upper end of the second piston rod 626c is fixedly connected to the fixing member on the side of the box body. The first and second hydraulic cylinders achieve the transmission of pressure through the hydraulic pipe.

[0081] The remaining implementation manners are the same as those in Embodiment 1.

[0082] The steps of using the adjusting device of the present invention to eliminate the undercut defect at the bottom of the weld are as follows:

[0083] S1. Before welding starts, external staff place the welded base material 3 on the welding tooling platform 8, connect to the excitation power supply interface 41, modulate the AC frequency to the preset frequency, and check the integrity of the circuit. As Figure 6a shown, at this time, the bottom of the weld is in a flat state;

[0084] S2. Adjust the relative position of the lower fixed bracket 610 and the adjusting bracket 69 to adjust the lifting ratio of the magnetic field assembly;

[0085] S3. Pass air flow into the air guide pipe 7. The air flow blows towards the weld of the welded base material through the air blowing port. After the air flow above the magnetic pole 53 is normal, start the transmission motor 82, and the transmission roller 84 longitudinally conveys the welded base material 3. The welding torch 1 and the laser head 2 start composite welding;

[0086] S4. The electromagnetic field generates a Lorentz force on the molten metal at the weld due to the longitudinal movement of the welded base material 3. As Figure 6bAs shown, at this time, since the Lorentz force is greater than the gravity of the weld pool, the bottom of the weld pool is concave upward. At this time, the air flow ejected from the air blowing port is guided along the lower edge of the air duct, and the wind pressure on the wind deflector increases, breaking the balance between the wind pressure F on the wind deflector and the tension of the first spring , that is . The wind deflector pushes the upper wedge block and the wind deflector outwards. During this process, the lower wedge block is lifted, driving the mechanical transmission mechanism to press down the box body, so that the magnetic pole moves away from the weld. The Lorentz force of the magnetic pole on the weld pool decreases, and the upward concavity of the weld pool is corrected;

[0087] S5. After the magnetic pole 53 moves away from the weld, the magnetic field strength at the weld will also weaken accordingly, and the Lorentz force received by the molten metal will also decrease correspondingly. As Figure 6c shown, when the magnetic pole leaves the weld too far, the Lorentz force it provides is not enough to overcome the downward fall of the metal in the weld pool, resulting in the bottom of the weld collapsing, that is, the bottom of the weld is convex downward. At this time, the air flow ejected from the air blowing port is guided along the upper edge of the air duct, that is, the wind blows upward and away from the wind deflector. Therefore, the wind pressure on the wind deflector decreases, breaking the balance between the wind pressure F on the wind deflector and the tension of the first spring , that is . The first spring pulls the upper wedge block and the wind deflector inwards. During this process, the lower wedge block is pressed down, driving the mechanical transmission mechanism to lift the box body, so that the magnetic pole approaches the weld. The Lorentz force of the magnetic pole on the weld pool increases, and the downward convexity of the weld pool is corrected;

[0088] S6. Steps S4 and S5 are repeated cyclically. After multiple cycles, that is, the lifting assembly swings multiple times between the positions where the Lorentz force is too large and too small, and finally automatically reaches the equilibrium position, that is . As Figure 6d shown, at this time, the bottom of the weld does not collapse or bulge upward, and the morphology of the weld reaches the expected shape.

[0089] The working principle of the present invention is:

[0090] As Figure 5a shown, when the bottom of the weld is flat (before welding starts), adjust the elasticity of the first spring connected to the outside of the wind deflector so that the wind pressure of the wind deflector reaches equilibrium with the tension of the first spring, and the lifting assembly reaches the equilibrium position. After calibrating the lifting assembly, then put the present invention into use.

[0091] When in use, as Figure 5bAs shown, when the magnetic pole is too far away from the weld seam, the Lorentz force it provides is not sufficient to overcome the downward fall of the molten metal in the weld pool, resulting in the bottom of the weld seam sagging and the bottom of the weld seam bulging upward. The lateral wind is directed to the upper edge of the air duct, that is, the wind is lifted upward and away from the windshield. Therefore, the wind pressure on the windshield decreases, breaking the balance between the wind pressure on the windshield and the tension of the first spring. The first spring pulls the upper wedge block and the windshield inward. During this process, the lower wedge block is pressed downward, driving the mechanical transmission mechanism to lift the box body, making the magnetic pole closer to the weld seam, increasing the Lorentz force of the magnetic pole on the weld pool, and correcting the upward bulge of the weld pool.

[0092] As Figure 5c shown, when the magnetic pole is too close to the weld seam, the Lorentz force acting on the weld pool is too large, resulting in the upward bulge of the weld pool and the downward concavity of the bottom of the weld pool. The lateral wind is directed to the lower edge of the air duct, and the wind pressure on the windshield increases, breaking the balance between the wind pressure on the windshield and the tension of the first spring. The windshield pushes the upper wedge block and the windshield outward. During this process, the lower wedge block is lifted upward, driving the mechanical transmission mechanism to press down the box body, making the magnetic pole away from the weld seam, reducing the Lorentz force of the magnetic pole on the weld pool, and correcting the downward concavity of the weld pool.

[0093] The lifting component of the present invention swings multiple times between the positions where the Lorentz force is too large and too small, and finally automatically reaches the equilibrium position. At this time, the bottom of the weld seam does not sag or bulge upward.

[0094] Referring Figure 9 to Figure 10 and

[0095] The above-described embodiments have detailed the technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, supplements, and equivalent replacements made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An electromagnetic field assisted laser-arc hybrid welding collapse defect adaptive control device, comprising a magnetic field component arranged on a welding tooling platform, the magnetic pole of the magnetic field component is close to the weld of the welding parent material, and the Lorentz force is applied to the bottom of the weld pool to suppress the collapse of the weld. The welding parent material is horizontally placed, the weld is longitudinally arranged, the horizontal plane is perpendicular to the weld direction as the horizontal side, and the horizontal side close to the weld is the inner side, characterized in that: The magnetic poles of the magnetic field assembly are arranged on the upper surface of the box body carrying the magnetic field assembly, and the gap between the magnetic poles is provided with the blowing port of the air guide pipe; the blowing port is vertically aligned with the bottom of the weld, so that the air outlet of the blowing port is directed to both sides through the bottom of the weld metal molten pool to form lateral wind; the air guide pipe is connected to the high-pressure gas source; The gap between the upper surface of the box body on both sides of the magnetic pole and the welding base material forms the wind channel for the lateral wind; The bottom of the box supports the second spring; Lifting assemblies are symmetrically arranged on both sides of the magnetic pole, and the lifting assemblies include a wind pressure transmission mechanism arranged horizontally and a mechanical transmission mechanism that drives the magnetic pole to lift vertically by the lateral movement of the wind pressure transmission mechanism; the wind pressure transmission mechanisms of the two lifting assemblies are in the same line in the lateral direction; The wind pressure transmission mechanism includes a wind shield, which is arranged at the bottom of the wind duct and faces the magnetic pole. The outer side of the wind shield is connected to an upper wedge, the inclined surface of the upper wedge faces downward, and the inner side is higher than the outer side. The upper wedge is connected to a first spring pre-tensioned inwardly. The upper wedge and the lower wedge are fitted to each other through the inclined surface and can be slidably connected to each other. One end of the mechanical transmission mechanism is connected to the lower wedge block, and the other end is connected to the box body carrying the magnetic field assembly, so as to convert the vertical movement of the lower wedge block into the vertical movement of the magnetic field assembly.

2. The self-adaptive regulation device for the undercut defect in electromagnetic field-assisted laser-arc hybrid welding according to claim 1, wherein, In the mechanical transmission mechanism, a vertical connecting rod is arranged on a vertical guide rail, the upper end of the vertical connecting rod is connected to the bottom of the lower wedge block, the axle pin at the lower end is passed through an axial long hole at one end of the adjusting connecting rod, and the axle pin at the other end of the adjusting connecting rod is passed through a transverse long hole of a fixed angle piece, the fixed angle piece is fixedly mounted on the box body, and the middle part of the adjusting connecting rod is hinged on the lower fixed bracket.

3. An adaptive control device for undercut defects in electromagnetic field-assisted laser-arc hybrid welding according to claim 2, characterized in that A plurality of adjustment through holes are provided in the middle of the adjustment connecting rod to change the relative positions of the lower fixed bracket and the adjustment connecting rod and adjust the lifting ratio of the magnetic field assembly.

4. An electromagnetic field-assisted laser-arc hybrid welding collapse defect adaptive control device according to claim 1, characterized in that, In the mechanical transmission mechanism, the vertical connecting rod is arranged on the vertical guide rail, the upper end of the vertical connecting rod is fixedly installed on the bottom of the lower wedge block, and a first rack is arranged on the inner side of the vertical connecting rod. The first rack is meshed with the gear, and the gear is meshed with the second rack on the side of the box body.

5. An adaptive control device for the undercut defect in electromagnetic field-assisted laser-arc hybrid welding according to claim 1, wherein In the mechanical transmission mechanism, the upper end of the first piston rod is fixedly mounted on the bottom of the lower wedge block, the lower end of the first piston rod is located in the first hydraulic cylinder, the first hydraulic cylinder is connected to the second hydraulic cylinder through a hydraulic pipe, the lower end of the second piston rod is located in the second hydraulic cylinder, and the upper end of the second piston rod is fixedly connected to the fixing part on the side of the box body.

6. An adaptive control device for undercut defects in electromagnetic field-assisted laser-arc hybrid welding according to claim 2 or 4, characterized in that, The vertical guide rail is an upper fixed bracket fixed on the box body at one end, and the other end of the upper fixed bracket is provided with a guide hole for the vertical connecting rod to pass through, so that the vertical connecting rod can only move in the vertical direction.

7. An adaptive control device for preventing collapse defects in electromagnetic field-assisted laser-arc hybrid welding according to claim 1, wherein The angle between the wind shield and the horizontal plane is 60°, and a plurality of ventilation holes are provided on the wind shield.

8. An electromagnetic field-assisted laser-arc hybrid welding collapse defect adaptive control device according to claim 1, wherein, The lower end of the air outlet has an isosceles trapezoid structure that is narrow at the top and wide at the bottom to increase the air flow velocity; a convex shape is provided at the position where the magnetic pole is close to the air outlet to change the air flow direction.

9. An adaptive control device for the undercut defect in electromagnetic field-assisted laser-arc hybrid welding according to claim 1, characterized in that, In the magnetic field assembly, the U-shaped iron core is arranged inside the box body through a fixed platform, and excitation coils are sleeved on the bottom and the transverse sides of the U-shaped iron core.

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