A device and method for applying auxiliary magnetic field in laser additive manufacturing process

Abstract

The present invention relates to an auxiliary magnetic field application device and method for a laser additive manufacturing process, and belongs to the field of laser directional energy deposition. Based on the process principle of energy field assisted laser cladding, a device that can apply an in-situ magnetic field during the laser cladding process is designed. It can be used for complex working conditions such as engine crankshafts where the cladding path has a high degree of variation. The device can be used to apply a follow-up auxiliary magnetic field to the workpiece during the laser cladding process. Applying a magnetic field to assist laser cladding can change the microstructure of the cladding layer to improve the material properties. The device specifically includes a horizontal auxiliary magnetic field application device, a moving device for the horizontal auxiliary magnetic field application device, a vertical auxiliary magnetic field application device, and a moving device for the vertical auxiliary magnetic field application device, a laser cladding head, an engine crankshaft, and a clamping device thereof. The position movement of the magnetic field application device is achieved by screw transmission, and the extension and retraction of the movable arm is achieved by rack and pinion transmission.

Description

Technical Field

[0001] The present invention relates to the field of laser directed energy deposition (LDED), and in particular to a device and method for applying an auxiliary magnetic field in a laser additive manufacturing process. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Laser Directed Energy Deposition (LDED) is an advanced additive manufacturing technology. Using a high-energy laser beam, LDED melts metal powder at a predetermined location using synchronized or pre-set powders, causing the metal powder to solidify into a new solid structure. Compared to traditional forming processes, LDED offers advantages such as shorter processing cycles, flexible design, high dimensional accuracy of formed parts, and environmental friendliness, providing greater design and manufacturing freedom and material utilization efficiency. LDED is suitable for the deposition of high-performance materials such as stainless steel and titanium alloys, and is widely used in aerospace, automotive, and energy industries.

[0004] In industrial applications, engine crankshafts often suffer surface damage such as wear, scratches, and cracks due to design defects, material defects, excessive loads, and poor lubrication. In recent years, laser cladding technology has been widely used in industrial production, and the use of laser cladding to repair damaged engine crankshafts has achieved remarkable results. In the process of using laser cladding technology to repair crankshafts, the rapid solidification of the molten pool will lead to uneven size and morphology of the solidified structure, making it anisotropic. At the same time, microscopic defects such as pores and cracks will appear in the cladding layer used for repair, seriously affecting the use effect of the coating.

[0005] Therefore, we use magnetic fields to assist in the remanufacturing and repair process during laser cladding of engine crankshafts. This magnetic field can control melt flow, enhance melt pool stability, and improve solidification conditions to achieve grain refinement, improve coating surface smoothness, reduce macroscopic and microscopic defects, optimize coating structure, and enhance coating mechanical properties. However, when applying magnetic field-assisted laser cladding, the magnitude, direction, and method of application of the magnetic field will all affect the final cladding coating effect.

[0006] However, the existing auxiliary magnetic field application for laser cladding is limited to a single working condition. Some auxiliary magnetic field application devices, such as the directional steady magnetic field application device disclosed in patent application number CN201710813192.1, can only be used for standard samples for laser cladding experiments. They are not suitable for complex working conditions and the magnetic field application direction is single, so their practicality needs to be improved.

[0007] Existing laser cladding auxiliary magnetic field application devices, such as the one described in patent application number CN202211731265, are used for laser cladding of high-speed rotating shaft surfaces. This device can move the high-speed rotating shaft axially to achieve the purpose of applying a magnetic field to every part of the rotating shaft surface. However, this device does not apply an in-situ magnetic field to assist laser cladding. Therefore, it is not suitable for workpieces with radial height variations, such as engine crankshafts. Moreover, it can only apply a unidirectional magnetic field to assist forming, which is also relatively complicated during clamping and has significant limitations.

[0008] Existing laser cladding auxiliary magnetic field application devices, such as the static magnetic field-laser coaxial composite cladding method and device described in patent application number 201310755461, can only apply an auxiliary magnetic field coaxial with the laser beam. The device is relatively simple and has limited applicable working conditions, which needs to be improved. Summary of the Invention

[0009] As described in the above background technology, the existing laser cladding auxiliary magnetic field application device has the problems of being unable to apply from different directions, the magnetic field size and form cannot be flexibly adjusted, poor practicality (mostly only used for experimental panels), inconvenient clamping or operation, and inability to apply magnetic field in situ to assist laser cladding. Therefore, the present invention optimizes and improves the existing laser cladding auxiliary magnetic field application device, and proposes a new laser additive manufacturing process auxiliary magnetic field application device and method.

[0010] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0011] In a first aspect, the present invention provides an auxiliary magnetic field application device for a laser additive manufacturing process, characterized in that it includes a vertical auxiliary magnetic field application device and a horizontal auxiliary magnetic field application device;

[0012] The vertical auxiliary magnetic field applying device includes an upper vertical auxiliary magnetic field generating electromagnetic coil and a lower vertical auxiliary magnetic field generating electromagnetic coil, wherein the upper vertical auxiliary magnetic field generating electromagnetic coil is in direct contact with the outer surface of the cladding head and is sleeved on the outer surface of the cladding head; the lower vertical auxiliary magnetic field generating electromagnetic coil is sleeved on a fixed iron core and is located below the workpiece;

[0013] The horizontal auxiliary magnetic field application device includes a horizontal auxiliary magnetic field generating electromagnetic coil, a horizontal auxiliary magnetic field application guiding device and a separable U-shaped iron core; the separable U-shaped iron core includes a left half core and a right half core, and the bottom of the left half core and the right half core are connected to a horizontal auxiliary magnetic field application guiding device, and the left half core and the right half core are both equipped with a horizontal auxiliary magnetic field generating electromagnetic coil. The left half core and the right half core can move toward or away from each other in the horizontal direction under the drive of the driving device.

[0014] The above-mentioned cladding head is used to provide coating powder to the workpiece and provide a laser heat source for cladding; the vertical auxiliary magnetic field application device is mainly used to provide a laser cladding auxiliary magnetic field in the coaxial direction with the cladding head; the horizontal auxiliary magnetic field application device is mainly used to apply a laser cladding auxiliary magnetic field along the radial direction of the engine crankshaft; the driving device of the horizontal auxiliary magnetic field application device is mainly used to adjust the horizontal distance between the horizontal magnetic field application device and the clamped workpiece. If necessary, the horizontal distance between the horizontal magnetic field application device and the clamped workpiece can also be adjusted to adjust the strength of the magnetic field assisting laser cladding in the horizontal direction.

[0015] As a further technical solution, the cladding head and the upper vertical auxiliary magnetic field generating electromagnetic coil are installed on the telescopic arm of the telescopic arm through a connecting frame, and the fixed iron core is fixed on the fixed arm of the telescopic arm, or the cladding head, the upper vertical auxiliary magnetic field and the fixed iron core are all installed on the telescopic arm of the telescopic arm through a connecting frame, so that the upper vertical auxiliary magnetic field generating electromagnetic coil and the lower vertical auxiliary magnetic field generating electromagnetic coil can move relative to each other up and down.

[0016] The above-mentioned retractable arm is mainly used to adjust the vertical distance between the vertical magnetic field application device and the workpiece. If necessary, the vertical distance between the vertical magnetic field application device and the clamped workpiece can also be adjusted to adjust the strength of the magnetic field assisting laser cladding in the vertical direction.

[0017] As a further technical solution, the driving device includes a motor, a screw transmission device and a sliding guide rail. A support frame is set on the top of the retractable arm, and a motor, a screw transmission device and a sliding guide rail are set on the top of the support frame; the motor drives the screw transmission device, and the left half iron core and the right half iron core are connected to the screw transmission device, carrying the left half iron core and the right half iron core to move along the sliding guide rail.

[0018] As a further technical solution, the horizontal auxiliary magnetic field application and guidance device comprises a metal sheet, one of which is positioned at the bottom of each of the left and right half-cores, with the two metal sheets parallel to each other. The magnetic field guidance device utilizes two parallelly mounted metal sheets. A DC power supply is provided to the electromagnetic coil to generate a stable magnetic field, which is then applied horizontally along the radial direction of the engine crankshaft via the magnetic field guidance device.

[0019] As a further technical solution, the upper vertical auxiliary magnetic field generating electromagnetic coil and the lower vertical auxiliary magnetic field generating electromagnetic coil are both connected to a DC power supply.

[0020] As a further technical solution, the electromagnetic coils for generating the auxiliary magnetic field in the horizontal direction are all connected to a DC power supply.

[0021] As a further technical solution, the left half core and the right half core are located on both sides of the cladding head.

[0022] In a second aspect, the present invention further provides a method for operating a laser additive manufacturing process auxiliary magnetic field application device, as follows:

[0023] Use a clamping device to clamp the workpiece to be processed.

[0024] Controlling the vertical auxiliary magnetic field applying device so that the upper vertical auxiliary magnetic field generating electromagnetic coil and the cladding head are located above the workpiece, and the lower vertical auxiliary magnetic field generating electromagnetic coil is located below the workpiece;

[0025] controlling the horizontal auxiliary magnetic field applying device so that the two horizontal auxiliary magnetic field applying guide devices are located on both sides of the workpiece;

[0026] Then the cladding system is turned on to process the workpiece, while the horizontal auxiliary magnetic field applying device and the vertical auxiliary magnetic field applying device apply vertical and horizontal magnetic fields to the workpiece.

[0027] As a further technical solution, the clamping device is a rotating device that drives the workpiece to be processed to rotate.

[0028] As a further technical solution, the telescopic arm can move as a whole along the axis to be processed with the auxiliary magnetic field application device of the laser additive manufacturing process.

[0029] Applying a magnetic field to assist laser cladding during the aforementioned cladding process can influence Marangoni convection in the molten pool, improving heat and mass transfer during the cladding process, and enhancing the performance and quality of the cladding layer. This refines the grain size within the cladding layer, significantly reduces cracks, facilitates the rise of impurities and the removal of bubbles from the molten pool, reduces surface roughness, improves the quality of the cladding layer, and enhances the wear, corrosion, and oxidation resistance of the component surface.

[0030] The beneficial effects of the present invention are:

[0031] 1. During the laser cladding process, the present invention can apply a laser cladding auxiliary magnetic field to the molten pool on the workpiece surface in the horizontal or vertical direction. By suppressing the flow of the molten pool caused by the laser through the static magnetic field, the purpose of improving the surface morphology of the cladding layer, optimizing stress distribution, regulating the solidification structure, reducing spatter during the cladding process, and reducing the number of defects can be achieved.

[0032] 2. The present invention realizes the synchronous movement of the auxiliary magnetic field and the cladding head during the laser cladding process, thereby ensuring the stability of the auxiliary magnetic field applied during the laser cladding process. At the same time, the field strength of the auxiliary magnetic field can be adjusted by adjusting the current provided by the power supply, or by controlling the distance between the vertical auxiliary magnetic field application device and the horizontal auxiliary magnetic field application device and the molten pool on the engine crankshaft surface.

[0033] 3. The present invention is different from other similar devices in the past. Most of the other patents achieve distance control between the workpiece and the cladding head and the laser cladding auxiliary magnetic field application device by moving the workpiece by means of a lifting platform, etc., which cannot achieve synchronous application of the auxiliary magnetic field. A major disadvantage of using this method to achieve distance control between the workpiece and the cladding head and the laser cladding auxiliary magnetic field application device is that it can only be applied to commonly used plates or other smaller samples with relatively regular geometric shapes in laser cladding experiments. Workpieces with complex surface geometric shapes such as engine crankshafts cannot achieve distance control between the workpiece and the cladding head and the laser cladding auxiliary magnetic field application device by this method. At the same time, other devices are more complicated to clamp, and most of the position adjustment requires manual adjustment. The present invention can apply an in-situ auxiliary magnetic field during the laser cladding process by controlling the moving device of the vertical auxiliary magnetic field application device and the moving device of the horizontal auxiliary magnetic field application device described in the invention through a servo motor, and is convenient and simple to clamp.

[0034] 4. The present invention has flexible control, simple device, low cost, and can be applied by simply modifying the original laser without redesigning or purchasing laser processing equipment. It has broad prospects for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The schematic implementation examples of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0036] Figure 1 Schematic diagram of the overall structure of a laser additive manufacturing process auxiliary magnetic field application device disclosed in an embodiment of the present invention;

[0037] Figure 2 Schematic diagram of the engine crankshaft clamping disclosed in an embodiment of the present invention;

[0038] Figure 3 Schematic diagram of a horizontal auxiliary magnetic field applying device and a moving device thereof disclosed in an embodiment of the present invention;

[0039] Figure 4 Schematic diagram of the internal structure of the three-section telescopic boom disclosed in an embodiment of the present invention.

[0040] Among them, 1. chuck bracket, 2. four-jaw chuck, 3. boom connecting flange, 4. cladding head, 5. engine crankshaft, 6. three-section retractable boom, 7. lower vertical auxiliary magnetic field generating electromagnetic coil, 8. support frame, 9. servo motor, 10. sliding guide rail, 11. cladding head connecting frame, 12. horizontal auxiliary magnetic field generating electromagnetic coil, 13. upper vertical auxiliary magnetic field generating electromagnetic coil, 14. fixed arm, 15. horizontal auxiliary magnetic field application guide device, 16. screw fixing support, 17. differential screw, 18. guide rail slider, 19. support slide, 20. screw nut, 21. separable U-shaped iron core, 22. boom, 23. three-section retractable boom middle section, 24. rack, 25. guide rail, 26. gear, 27. guide rail groove. DETAILED DESCRIPTION

[0041] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0042] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless otherwise clearly indicated in the present invention, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "comprising" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations;

[0043] As introduced in the background technology and invention content, in view of the shortcomings of the existing method of applying auxiliary magnetic fields in the laser cladding process, the purpose of the present invention is to provide a horizontal laser cladding auxiliary magnetic field that can apply a horizontal auxiliary magnetic field parallel to the radial cross-section of the engine crankshaft and similar workpieces, and can apply a vertical laser cladding auxiliary magnetic field that is coaxial with the cladding head, and can utilize the moving device of the horizontal auxiliary magnetic field applying device and the moving device of the vertical auxiliary magnetic field applying device to realize the distance control of the magnetic field applying device during the clamping and processing process and the in-situ application of the auxiliary magnetic field. The device has the functions of improving the performance of the cladding coating, controlling the field strength in multiple ways as needed, and being able to apply the auxiliary magnetic field in situ under complex working conditions. It is now explained in conjunction with the embodiments and drawings.

[0044] In a typical embodiment of the present invention, the present invention proposes a device that can apply a horizontal laser cladding auxiliary magnetic field parallel to the radial section of an engine crankshaft and similar workpieces, and can apply a vertical laser cladding auxiliary magnetic field coaxial with the cladding head, and can use a moving device of the horizontal auxiliary magnetic field applying device and a moving device of the vertical auxiliary magnetic field applying device to achieve distance control of the magnetic field applying device during clamping and processing and to achieve in-situ application of the auxiliary magnetic field. The overall structural diagram of the device is shown in FIG. Figure 1 As shown, the device uses a four-jaw chuck as a clamping device, improves the last-stage arm of a six-axis robot, and upgrades the cladding head. The device includes a horizontal auxiliary magnetic field application device, a horizontal auxiliary magnetic field application device movement device, a vertical auxiliary magnetic field application device, and a vertical auxiliary magnetic field application device movement device. It is connected to the upper-stage arm via two arm connection flanges 3. The device specifically includes the horizontal auxiliary magnetic field application device, the horizontal auxiliary magnetic field application device movement device, the vertical auxiliary magnetic field application device, the vertical auxiliary magnetic field application device movement device, the laser cladding head, and a clamping device for the engine crankshaft.

[0045] The present invention applies a magnetic field to assist laser cladding during the cladding process, which can influence Marangoni convection in the molten pool, improve heat and mass transfer during the cladding process, and enhance the performance and quality of the cladding layer. This refines the grain size within the cladding layer, significantly reduces cracks, facilitates the floating of impurities and the removal of bubbles in the cladding pool, reduces surface roughness, improves the cladding layer's quality, and enhances the wear, corrosion, and oxidation resistance of component surfaces.

[0046] The above structure is described in detail below with reference to the accompanying drawings;

[0047] As attached Figure 2 As shown, the clamping device disclosed in the present invention consists of a chuck support 1 and a four-jaw chuck 2 . The four-jaw chuck 2 is fixed on the chuck support 1 , and one end of the engine crankshaft 5 is fixedly clamped on the four-jaw chuck 2 .

[0048] like Figure 1 and Figure 3As shown, the cladding head of the present invention is a cladding head for synchronous powder feeding laser cladding equipment, specifically used to provide remanufacturing and repair coating powder for engine crankshafts, and to provide a laser heat source for cladding. The disclosed laser cladding head 4 is connected to a three-section telescopic boom 6 via a cladding head connecting frame 11. The cladding head 4 is connected to a powder feed pipe, a shielding gas delivery pipe, and a laser generator. Powder is delivered by the powder feeder, through the powder feed pipe and the powder channel within the cladding head, to the surface of the engine crankshaft 5. Argon gas is delivered from an argon tank via a delivery pipe to the front end of the cladding head as shielding gas. Laser light generated by the laser generator is transmitted through the laser transmission channel as a heat source and irradiates the surface of the engine crankshaft. During operation, the laser moves from one end of the engine crankshaft 5 to the other end along a predetermined path.

[0049] like Figure 1 and Figure 3 As shown, the vertical auxiliary magnetic field application device disclosed in the present invention is primarily used to provide a laser cladding auxiliary magnetic field coaxially with the cladding head. The vertical auxiliary magnetic field application device consists of two parts, both of which include electromagnetic coils. The upper electromagnetic coil is enclosed on the outer wall of the cladding head, while the lower electromagnetic coil is enclosed on the iron core connected to the last stage of the robot arm. A DC power supply is provided to the electromagnetic coil to generate a stable magnetic field coaxially with the cladding head.

[0050] Specifically, in this embodiment, the vertical auxiliary magnetic field application device is composed of an upper vertical auxiliary magnetic field generating electromagnetic coil 13 and a lower vertical auxiliary magnetic field generating electromagnetic coil 7. The upper vertical auxiliary magnetic field generating electromagnetic coil 13 is directly in contact with the outer surface of the cladding head 4. The upper vertical auxiliary magnetic field generating electromagnetic coil 13 is connected to a stable DC power supply. The switch and size of the DC power supply are controlled according to a program designed according to actual work needs to achieve the purpose of whether to apply a steady-state magnetic field and control the strength of the steady-state magnetic field; the lower vertical auxiliary magnetic field generating electromagnetic coil 7 is fixed on the iron core of the free end of the fixed arm 14 connected to the three-section telescopic boom 6, and the specific usage method is the same as that of the upper vertical auxiliary magnetic field generating electromagnetic coil 13.

[0051] like Figure 3 As shown, the horizontal auxiliary magnetic field application device disclosed in the present invention is mainly used to apply a laser cladding auxiliary magnetic field in the radial direction of the engine crankshaft; the horizontal auxiliary magnetic field application device is composed of a horizontal auxiliary magnetic field generating electromagnetic coil 12, a horizontal auxiliary magnetic field application guide device 15 and a separable U-shaped iron core 21.

[0052] The separable U-shaped core 21 comprises two identically structured parts, a left half and a right half, which are disposed opposite each other. A horizontal auxiliary magnetic field generating electromagnetic coil 12 is wound around each of the left and right U-shaped cores, and a horizontal auxiliary magnetic field applying guide device 15 is connected to the bottom of each of the left and right U-shaped cores.

[0053] Specifically, the horizontal auxiliary magnetic field applying and guiding device 15 is two iron sheets, which are installed in parallel at the bottom of the separable U-shaped iron core 21. By providing a DC power supply, the electromagnetic coil generates a stable magnetic field, and the magnetic field guiding device allows the stable magnetic field to be applied horizontally along the radial direction of the engine crankshaft.

[0054] Specifically, the above-mentioned separable U-shaped iron core 21 is connected to the differential screw 17 by a screw nut, and is supported by the support slide 19 on the guide rail slider 18. The horizontal auxiliary magnetic field generating electromagnetic coil 12 is connected to a stable DC power supply. During operation, according to work needs, the current switch and size are controlled by a pre-written program to achieve the purpose of controlling the auxiliary magnetic field. After the DC power supply is turned on, the electromagnetic coil generates a stable magnetic field according to Faraday's law of electromagnetic induction. The magnetic field is conducted along the separable U-shaped iron core 21 to form a loop. Under the guidance of the horizontal auxiliary magnetic field application guide device 15, a stable magnetic field is formed in the middle of the two parallel iron sheets, which is applied to the surface of the engine crankshaft 5 to achieve the purpose of assisting the laser cladding process.

[0055] like Figure 3 As shown, the movable device of the horizontal auxiliary magnetic field applying device disclosed in the present invention is mainly used to adjust the horizontal distance between the horizontal magnetic field applying device and the clamped engine crankshaft. If necessary, the horizontal distance between the horizontal magnetic field applying device and the clamped engine crankshaft can also be adjusted to adjust the horizontal magnetic field strength of the auxiliary laser cladding. The movable device of the horizontal auxiliary magnetic field applying device is composed of a supporting slide 19, a guide rail slider 18, a sliding guide rail 10, a screw fixing support 16, a differential screw 17, a screw nut 20, a support frame 8 and a servo motor 9.

[0056] The above-mentioned support frame 8 is connected to the three-stage telescopic boom 6 and serves as the overall support of the entire device. The sliding guide rail 10 is fixed to the top of the support frame 8. A screw fixing support 16 is provided at one end of the support frame 8, and a servo motor 9 is provided at the other end of the support frame 8. One end of the differential screw 17 is fixed by the screw fixing support 16, and the other end is connected to the servo motor 9; the support slide 19 is connected to the guide rail slider 18, and the guide rail slider is connected to slide on the sliding guide rail 10, and one end of the sliding guide rail 10 is fixed to the support frame 8 connected to the last-stage boom of the robot arm, and the other end is fixed to the last-stage boom of the robot arm;

[0057] The left half and the right half of the separable U-shaped iron core 21 are respectively connected to the differential screw 17 through the screw nut 20, and can move toward or away from each other under the drive of the differential screw 17. The left half and the right half of the separable U-shaped iron core 21 are respectively supported by a support slide 19, and the support slide 19 supports the sliding of the separable U-shaped iron core 21. The support slide 19 shown is fixedly connected to the guide rail slider 18, and the guide rail slider 18 is connected to the sliding guide rail 10 and slides along the sliding guide rail 10 under the control of the servo motor 9.

[0058] During clamping, the servo motor 9 provides power, so that the separable U-shaped iron core 21 moves to the appropriate position at both ends along the sliding guide rail 10 under the action of the differential screw so that there is enough space for convenient clamping; during the cladding process, the horizontal auxiliary magnetic field application device moves synchronously with the cladding head. During this movement, the width of the engine crankshaft will change. At this time, the servo motor 9 provides power, so that the separable U-shaped iron core 21 moves to the appropriate position at both ends along the guide rail under the action of the differential screw 17 so that the magnetic field for in-situ auxiliary laser cladding can be applied during the cladding process.

[0059] like Figure 4 As shown, the movable device of the vertical auxiliary magnetic field applying device disclosed in the present invention is mainly used to adjust the vertical distance between the vertical magnetic field applying device and the clamped engine crankshaft. If necessary, the vertical distance between the vertical magnetic field applying device and the clamped engine crankshaft can also be adjusted to adjust the vertical magnetic field strength of the auxiliary laser cladding. It is mainly composed of a three-section retractable arm 6. Figure 4This is a schematic diagram of the specific structure of the three-section telescopic boom 6. The three-section telescopic boom 6 consists of an upper and lower boom 22 and a three-section telescopic boom middle section 23. The upper and lower boom 22 specifically include a rack 24 and a guide rail 25. The three-section telescopic boom middle section 23 specifically includes four transmission gears 26 and a dovetail guide rail groove 27. Under the control of the servo motor, the distance control between the vertical auxiliary magnetic field application device and the engine crankshaft is achieved through the extension and retraction of the three-section telescopic boom 6. Specifically, during clamping, the servo motor built into the three-stage telescopic arm 6 provides power, allowing it to extend to the appropriate position to prevent the lower vertical auxiliary magnetic field application device from colliding with the crankshaft, facilitating clamping. During the cladding process, the vertical auxiliary magnetic field application device moves synchronously with the cladding head. During this movement, the vertical height of the engine crankshaft changes. At this time, the servo motor provides power to extend the three-stage telescopic arm 6 to the appropriate position to apply the magnetic field that in-situ assists laser cladding during the cladding process. The cladding head is connected to the last stage arm of the six-degree-of-freedom robot arm using a bracket; the cladding head is connected to the powder feed pipe, shielding gas delivery pipe, and laser generator. The powder is transported by the powder feeder and delivered to the surface of the engine crankshaft through the powder feeding pipe and the powder channel inside the cladding head. Argon gas is transported from the argon tank to the front end of the cladding head through the delivery pipe as a protective gas. The laser generated by the laser generator is irradiated on the surface of the engine crankshaft through the laser transmission channel as a heat source. Under the action of the protective gas, the powder material is melted on the surface of the engine crankshaft to form a cladding coating.

[0060] Furthermore, the specific method of using the above device is as follows:

[0061] In the initial clamping and tool setting process, the moving device of the horizontal auxiliary magnetic field applying device and the moving device of the vertical auxiliary magnetic field applying device should be controlled first to expand the horizontal auxiliary magnetic field applying guide device 15 in the horizontal auxiliary magnetic field applying device to a suitable distance and control the vertical auxiliary magnetic field applying device to extend the three-section telescopic movable arm 6 to a suitable length, first make the axis of the engine crankshaft 5 perpendicular to the axis of the cladding head 4, and then control the robot arm to clamp the engine crankshaft 5 in the middle of the horizontal auxiliary magnetic field applying guide device 15, and then control the three-section telescopic movable arm 6 to shrink to a suitable distance, so that the preliminary tool setting steps can be completed. In the actual cladding process, the cladding head 4 moves from one end of the engine crankshaft 5 to the other. During the cladding process, the engine crankshaft will experience changes in height and radial width. When the height increases, the robotic arm controls the cladding head 4 to rise while simultaneously controlling the extension of the three-stage telescopic boom 6. When the cladding head 4 reaches the target position, the three-stage telescopic boom 6 is retracted. The same applies when the height decreases. When the radial width of the engine crankshaft 5 changes during the process, the horizontal auxiliary magnetic field application device's moving device is controlled to expand the horizontal auxiliary magnetic field application guide device 15 therein to an appropriate distance until the wider portion is passed. The horizontal auxiliary magnetic field application guide device 15 is then controlled to retract to an appropriate distance. When the cladding process is completed, the three-stage telescopic boom 6 is first controlled to extend, and then the horizontal auxiliary magnetic field application device's moving device is controlled to expand the horizontal auxiliary magnetic field application guide device 15 therein to an appropriate distance. The robotic arm is then raised to a position where the engine crankshaft 5 cannot be clamped by the horizontal auxiliary magnetic field application guide device 15, and the robotic arm is controlled to return to its original position.

[0062] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A laser additive manufacturing process auxiliary magnetic field application device, characterized in that: Including vertical assist A magnetic field applying device and a horizontal auxiliary magnetic field applying device; the strength of the auxiliary magnetic field is adjusted by controlling the distance between the vertical auxiliary magnetic field applying device and the horizontal auxiliary magnetic field applying device and the molten pool on the workpiece surface; The vertical auxiliary magnetic field applying device includes an upper vertical auxiliary magnetic field generating electromagnetic coil and a lower vertical auxiliary magnetic field generating electromagnetic coil, wherein the upper vertical auxiliary magnetic field generating electromagnetic coil is in direct contact with the outer surface of the cladding head and is sleeved on the outer surface of the cladding head; The lower vertical auxiliary magnetic field generating electromagnetic coil is sleeved on a fixed iron core and is located below the workpiece; The horizontal auxiliary magnetic field applying device includes a horizontal auxiliary magnetic field generating electromagnetic coil, a horizontal auxiliary magnetic field applying guiding device and a separable U-shaped iron core; the separable U-shaped iron core includes a left half core and a right half core, the bottoms of the left half core and the right half core are connected to the horizontal auxiliary magnetic field applying guiding device, and the left half core and the right half core are both equipped with a horizontal auxiliary magnetic field generating electromagnetic coil, and the left half core and the right half core can move toward or away from each other in the horizontal direction under the drive of the driving device; The cladding head and the upper vertical auxiliary magnetic field generating electromagnetic coil are mounted on the telescopic arm of the telescopic boom via a connecting frame, and the fixed iron core is fixed to the fixed arm of the telescopic boom, or the cladding head, the upper vertical auxiliary magnetic field and the fixed iron core are all mounted on the telescopic arm of the telescopic boom via a connecting frame, so that the upper vertical auxiliary magnetic field generating electromagnetic coil and the lower vertical auxiliary magnetic field generating electromagnetic coil can move relative to each other up and down; The driving device includes a motor, a screw transmission device and a sliding guide rail. A support frame is provided on the top of the telescopic movable arm, and a motor, a screw transmission device and a sliding guide rail are provided on the top of the support frame. The motor drives the screw transmission device, and the left half iron core and the right half iron core are connected to the screw transmission device, and the left half iron core and the right half iron core move along the sliding guide rail. The horizontal auxiliary magnetic field applying and guiding device is a metal sheet. A metal sheet is provided at the bottom of each of the left half iron core and the right half iron core, and the two metal sheets are parallel to each other.

2. The laser additive manufacturing process auxiliary magnetic field application device according to claim 1, characterized in that: The upper vertical auxiliary magnetic field generating electromagnetic coil and the lower vertical auxiliary magnetic field generating electromagnetic coil are both connected to a DC power supply.

3. The laser additive manufacturing process auxiliary magnetic field application device according to claim 1, characterized in that: The electromagnetic coils for generating the horizontal auxiliary magnetic field are all connected to a DC power supply.

4. The laser additive manufacturing process auxiliary magnetic field application device according to claim 1, characterized in that: The left half core and the right half core are located on both sides of the cladding head.

5. The operating method of the laser additive manufacturing process auxiliary magnetic field application device according to any one of claims 1 to 4, characterized in that: Use a clamping device to clamp the workpiece to be processed. Controlling the vertical auxiliary magnetic field applying device so that the upper vertical auxiliary magnetic field generating electromagnetic coil and the cladding head are located above the workpiece, and the lower vertical auxiliary magnetic field generating electromagnetic coil is located below the workpiece; controlling the horizontal auxiliary magnetic field applying device so that the two horizontal auxiliary magnetic field applying guide devices are located on both sides of the workpiece; Then the cladding system is turned on to process the workpiece, while the horizontal auxiliary magnetic field applying device and the vertical auxiliary magnetic field applying device apply vertical and horizontal magnetic fields to the workpiece.

6. The operating method of the laser additive manufacturing process auxiliary magnetic field application device according to claim 5, characterized in that: The clamping device is a rotating device that drives the workpiece to be processed to rotate.

7. The operating method of the laser additive manufacturing process auxiliary magnetic field application device according to claim 5, characterized in that: The telescopic movable arm can move along the axis to be processed as a whole, carrying the auxiliary magnetic field application device in the laser additive manufacturing process.

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