Auxiliary magnetic field applying device and method in laser additive manufacturing process

Abstract

The invention relates to an auxiliary magnetic field applying device and method in the laser additive manufacturing process, and belongs to the field of laser directional energy deposition. The device capable of applying the in-situ magnetic field in the laser cladding process is designed on the basis of the process principle of energy field assisted laser cladding, the device can be used for complex working conditions such as engine crankshafts with height change of cladding paths, and the follow-up auxiliary magnetic field can be applied to workpieces in the laser cladding process by means of the device. The microscopic composition of the cladding layer can be changed by applying the magnetic field to assist laser cladding so as to improve the material performance. The device specifically comprises a horizontal auxiliary magnetic field applying device, a moving device of the horizontal auxiliary magnetic field applying device, a vertical auxiliary magnetic field applying device, equipment of a moving device of the vertical auxiliary magnetic field applying device, a laser cladding head, an engine crankshaft and a clamping device of the engine crankshaft. The position movement of the magnetic field applying device is realized in a lead screw transmission mode, and the extension and retraction of the movable arm are realized in a gear and rack transmission mode.

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 (LDE) is an advanced additive manufacturing technology. LDE uses a high-energy laser beam to melt metal powder materials at a preset position by synchronizing or presetting powders, so that the metal powder materials solidify into a new solid structure. Compared with traditional forming processes, LDE has a series of characteristics such as short processing cycle, flexible design, high dimensional accuracy of formed parts, and green environmental protection, providing higher design and manufacturing freedom and material utilization efficiency. LDE is suitable for the deposition of high-performance materials, such as stainless steel, titanium alloy, etc., and is widely used in aerospace, automobile manufacturing, energy industry and other fields.

[0004] In industrial applications, engine crankshafts often suffer from surface wear, abrasions, cracks and other damages 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, which seriously affects the use effect of the coating.

[0005] Therefore, we apply magnetic field to assist the remanufacturing and repair process during the laser cladding process to repair the engine crankshaft. The magnetic field can be used to control the melt flow, enhance the stability of the molten pool, and improve the solidification conditions to achieve the effect of grain refinement, improve the surface flatness of the coating, reduce macro and micro defects, optimize the coating structure, and improve the mechanical properties of the coating. However, when applying magnetic field to assist laser cladding, the size, direction, and method of the magnetic field will affect the final cladding coating effect.

[0006] However, the existing laser cladding auxiliary magnetic field application can only be applied under a single working condition. Some auxiliary magnetic field application devices, such as a directional and constant magnetic field application device disclosed in patent application number CN201710813192.1, can only be used for standard samples for laser cladding experiments, and cannot be applied under complex working conditions. The magnetic field application direction is single, and its practicality needs to be improved.

[0007] Existing laser cladding auxiliary magnetic field application devices, such as patent application number CN202211731265., are a laser cladding magnetic field auxiliary application device for the surface of a high-speed shaft. The device can make the high-speed shaft move axially to achieve the purpose of applying the magnetic field to every part of the shaft surface. However, the device does not apply an in-situ magnetic field to assist laser cladding. Therefore, it is not suitable for workpieces with radial height changes such as engine crankshafts, and it can only apply a unidirectional magnetic field for auxiliary molding. It is also more complicated during clamping and has greater limitations.

[0008] Existing laser cladding auxiliary magnetic field application devices, such as patent application number 201310755461, describe a static magnetic field-laser coaxial composite cladding method and device. The patent 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, low 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 by 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 comprises a vertical auxiliary magnetic field application device and a horizontal auxiliary magnetic field application device;

[0012] The vertical auxiliary magnetic field applying device comprises 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 directly in 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 the 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, 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.

[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, and 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 boom through a connecting frame, and the fixed iron core is fixed on the fixed arm of the telescopic boom, 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 boom 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 up and down relative to each other.

[0016] The telescopic arm is mainly used to adjust the distance between the vertical magnetic field application device and the workpiece in the vertical direction. If necessary, the vertical magnetic field strength for assisting laser cladding can also be adjusted by adjusting the distance between the vertical magnetic field application device and the clamped workpiece 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 arranged on the top of the retractable arm, and a motor, a screw transmission device and a sliding guide rail are arranged 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, driving 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 guiding device is a metal sheet, and one metal sheet is respectively arranged at the bottom of the left half iron core and the right half iron core, and the two metal sheets are parallel to each other. The magnetic field guiding device uses two iron sheets to be installed in parallel, and a DC power supply is provided to enable the electromagnetic coil to generate a stable magnetic field, and the magnetic field guiding device enables the stable magnetic field to be horizontally applied along the radial direction of the engine crankshaft.

[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 direct current 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 also provides a working method of 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 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, and at the same time, 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 laser additive manufacturing process auxiliary magnetic field application device.

[0029] Applying magnetic field to assist laser cladding in the above cladding process can affect Marangoni convection in the molten pool, improve heat transfer and mass transfer in the cladding process, and improve the performance and quality of the cladding layer. It can refine the grains in the cladding layer, greatly reduce cracks, facilitate the floating of impurities and the discharge of bubbles in the molten pool, reduce the surface roughness of the cladding layer, improve the quality of the cladding layer, and enhance the wear resistance, corrosion resistance, and oxidation resistance of the surface of the parts.

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

[0031] 1. In the process of laser cladding, the present invention can apply a laser cladding auxiliary magnetic field to the molten pool on the surface of the workpiece from a horizontal or vertical direction. By suppressing the flow of the molten pool caused by the laser through the static magnetic field, the purposes of improving the surface morphology of the cladding layer, optimizing the stress distribution, regulating the solidification structure, reducing the spatter phenomenon in 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 surface of the engine crankshaft to adjust the field strength of the auxiliary magnetic field.

[0033] 3. The present invention is different from other similar devices in the past. Most of the other patents realize the 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 the synchronous application of the auxiliary magnetic field. Moreover, a great disadvantage of realizing the distance control between the workpiece and the cladding head and the laser cladding auxiliary magnetic field application device by this method is that it can only be applied to the commonly used plates or other smaller samples with regular geometric shapes in laser cladding experiments. Workpieces with complex surface geometric shapes such as engine crankshafts cannot realize the 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 control 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 by a servo motor to apply an in-situ auxiliary magnetic field during the laser cladding process, and it is convenient and simple to clamp.

[0034] 4. The present invention is flexible in regulation, simple in device, and low in cost. It 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 It is a 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 It is a schematic diagram of the clamping of the engine crankshaft disclosed in the embodiment of the present invention;

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

[0039] Figure 4 It is a 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-stage 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 applying guide device, 16. screw fixing support, 17. differential screw, 18. guide rail slider, 19. support slide plate, 20. screw nut, 21. separable U-shaped iron core, 22. boom, 23. three-stage 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 descriptions are illustrative and 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 meanings as those 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 explicitly stated 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 "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof;

[0043] As introduced in the background technology and the invention content, in view of the shortcomings of the existing method of applying auxiliary magnetic field 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 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 realize 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 the 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 coaxially 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 schematic diagram of the device is shown in FIG. Figure 1 As shown, the device uses a four-claw chuck as a clamping device, improves the last-stage arm of the six-axis robot, upgrades the cladding head, and includes a horizontal auxiliary magnetic field applying device, a moving device of the horizontal auxiliary magnetic field applying device, a vertical auxiliary magnetic field applying device, and a moving device of the vertical auxiliary magnetic field applying device; it is connected to the upper-stage arm through two arm flanges 3. The device specifically includes a horizontal auxiliary magnetic field applying device, a moving device of the horizontal auxiliary magnetic field applying device, a vertical auxiliary magnetic field applying device, a moving device of the vertical auxiliary magnetic field applying device, a laser cladding head, and a clamping device for the engine crankshaft.

[0045] The present invention applies magnetic field to assist laser cladding during the cladding process, which can affect Marangoni convection in the molten pool, improve heat transfer and mass transfer in the cladding process, and improve the performance and quality of the cladding layer. It refines the grains in the cladding layer, greatly reduces cracks, facilitates the floating of impurities and the discharge of bubbles in the molten pool, reduces the surface roughness of the cladding layer, improves the quality of the cladding layer, and enhances the wear resistance, corrosion resistance, and oxidation resistance of the surface of the parts.

[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 is composed 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 of a synchronous powder feeding laser cladding equipment, which is specifically used to provide remanufacturing and repairing coating powder for remanufacturing and repairing engine crankshafts, and provide a laser heat source for cladding; the disclosed laser cladding head 4 is connected to the three-stage telescopic boom 6 through the cladding head connecting frame 11, and the cladding head 4 is connected to the powder feeding pipe, the protective gas delivery pipe, and the laser generator. The powder is transported by the powder feeder and delivered to the surface of the engine crankshaft 5 through the powder feeding pipe and the powder channel in the cladding head. Argon is transported from the argon tank through the delivery pipe to the front end of the cladding head 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. When working, it moves from one end of the engine crankshaft 5 to the other end of the engine crankshaft 5 according to the set path.

[0049] like Figure 1 and Figure 3 As shown, the vertical auxiliary magnetic field applying device disclosed in the present invention is mainly used to provide a laser cladding auxiliary magnetic field in the coaxial direction with the cladding head; the vertical auxiliary magnetic field applying device is divided into an upper and lower part, and both the upper and lower parts include electromagnetic coils. The upper electromagnetic coil is sleeved on the outer wall of the cladding head, and the lower electromagnetic coil is sleeved on the iron core connected to the last stage of the robot arm. By providing a DC power supply, the electromagnetic coil generates a stable magnetic field, and the direction of the magnetic field is coaxial with the cladding head.

[0050] Specifically, in the present embodiment, the vertical auxiliary magnetic field applying 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 switching 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 magnitude 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 retractable boom 6, and the specific use 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 radial laser cladding auxiliary magnetic field to 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 guiding device 15 and a separable U-shaped iron core 21.

[0052] The separable U-shaped core 21 comprises two parts of the same structure, namely a left half and a right half, which are arranged opposite to each other; a horizontal auxiliary magnetic field generating electromagnetic coil 12 is wound on both the left half U-shaped core and the right half U-shaped core, and a horizontal auxiliary magnetic field applying guide device 15 is also connected to the bottom of each of the left half U-shaped core and the right half U-shaped core;

[0053] Specifically, the horizontal auxiliary magnetic field applying guide device 15 is two iron sheets, which are parallelly installed at the bottom of the separable U-shaped iron core 21; a DC power supply is provided to enable the electromagnetic coil to generate a stable magnetic field, and the magnetic field guiding device enables the stable magnetic field to be horizontally applied 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 a 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. When working, 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 guiding device 15, a stable magnetic field is formed in the middle of the two parallel iron sheets and applied to the surface of the engine crankshaft 5 to achieve the effect of assisting the laser cladding process.

[0055] like Figure 3 As shown, the moving device of the horizontal auxiliary magnetic field applying device disclosed in the present invention is mainly used to adjust the distance in the horizontal direction 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 magnetic field strength of the auxiliary laser cladding in the horizontal direction; the moving device of the horizontal auxiliary magnetic field applying device is composed of a supporting slide plate 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 as the overall support of the entire device, the sliding guide rail 10 is fixed on the top of the support frame 8, a screw rod fixing support 16 is arranged at one end of the support frame 8, and a servo motor 9 is arranged at the other end of the support frame 8. One end of the differential screw 17 is fixed by the screw rod fixing support 16, and the other end is connected to the servo motor 9; the support slide plate 19 is connected to the guide rail slider 18, and the guide rail slider is connected to slide on the sliding guide rail 10, 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 and right halves of the separable U-shaped iron core 21 are respectively connected to the differential screw 17 through a screw nut 20, and can move toward or away from each other under the drive of the differential screw 17. The left and right halves of the separable U-shaped iron core 21 are respectively supported by a supporting slide 19, and the supporting slide 19 supports the sliding of the separable U-shaped iron core 21. The supporting 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 positions at both ends along the sliding guide rails 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 positions at both ends along the guide rails 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 moving device of the vertical auxiliary magnetic field applying device disclosed in the present invention is mainly used to adjust the distance in the vertical direction between the vertical magnetic field applying device and the clamped engine crankshaft. If necessary, the vertical magnetic field strength of the auxiliary laser cladding can be adjusted by adjusting the distance in the vertical direction between the vertical magnetic field applying device and the clamped engine crankshaft. It is mainly composed of a three-section telescopic movable arm 6, Figure 4It 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 groove 27. Under the control of the servo motor, the distance control between the vertical auxiliary magnetic field application device and the engine crankshaft 6 is achieved through the extension and retraction of the three-section telescopic boom 6. Specifically, during clamping, the built-in servo motor of the three-stage telescopic arm 6 provides power to extend the three-stage telescopic arm 6 to a suitable position to avoid the collision between the lower part of the vertical auxiliary magnetic field application device and the crankshaft, so as to facilitate clamping; during the cladding process, the vertical auxiliary magnetic field application device moves synchronously with the cladding head. During this movement, the height of the engine crankshaft in the vertical direction will change. At this time, the servo motor provides power to extend the three-stage telescopic arm 6 to a suitable position so that the magnetic field for in-situ auxiliary laser cladding can be applied during the cladding process. The above-mentioned cladding head bracket is connected to the last stage arm of the six-degree-of-freedom robot arm; the cladding head is connected to the powder delivery pipe, the protective gas delivery pipe, and the laser generator. The powder is transported by the powder feeder and delivered to the surface of the engine crankshaft through the powder delivery pipe and the powder channel in 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 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 application device and the moving device of the vertical auxiliary magnetic field application device should be controlled first to expand the horizontal auxiliary magnetic field application guide device 15 in the horizontal auxiliary magnetic field application device to a suitable distance and control the vertical auxiliary magnetic field application device to extend the three-stage telescopic arm 6 to a suitable length, first make the axis of the engine crankshaft 5 perpendicular to the axis of the cladding head 4, then control the mechanical arm to clamp the engine crankshaft 5 in the middle of the horizontal auxiliary magnetic field application guide device 15, and then control the three-stage telescopic 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 process of the engine crankshaft 5, the height and radial width of the engine crankshaft will change. When the height is raised, the mechanical arm controls the cladding head 4 to rise while controlling the three-stage telescopic arm 6 to extend. When the cladding head 4 reaches the target position, the three-stage telescopic arm 6 is retracted. The same applies when the height is lowered. When the radial width of the engine crankshaft 5 changes during the process, the moving device of the horizontal auxiliary magnetic field application device is controlled to expand the horizontal auxiliary magnetic field application guide device 15 in the horizontal auxiliary magnetic field application device to a suitable distance until the wider part is passed, and then the moving device of the horizontal auxiliary magnetic field application device is controlled to shrink the horizontal auxiliary magnetic field application guide device 15 in the horizontal auxiliary magnetic field application device to a suitable distance. When the cladding process is finished, the three-stage telescopic arm 6 is controlled to extend first, and then the moving device of the horizontal auxiliary magnetic field application device is controlled to expand the horizontal auxiliary magnetic field application guide device 15 in the horizontal auxiliary magnetic field application device to a suitable distance, and then the mechanical arm is lifted to a position where the engine crankshaft 5 cannot be clamped by the horizontal auxiliary magnetic field application guide device 15, and the mechanical arm is controlled to return to its original position.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A laser additive manufacturing process auxiliary magnetic field application device, characterized in that: It includes a vertical auxiliary magnetic field applying device and a horizontal auxiliary magnetic field applying device; The vertical auxiliary magnetic field applying device comprises 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 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 the 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, 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.

2. The laser additive manufacturing process auxiliary magnetic field application device according to claim 1, characterized in that: The cladding head and the upper vertical auxiliary magnetic field generating electromagnetic coil are installed on the telescopic arm of the telescopic boom through a connecting frame, and the fixed iron core is fixed on the fixed arm of the telescopic boom, 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 boom 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 up and down relatively.

3. The laser additive manufacturing process auxiliary magnetic field application device according to claim 2, characterized in that: The driving device includes a motor, a screw transmission device and a sliding guide rail. A support frame is arranged on the top of the telescopic arm, and a motor, a screw transmission device and a sliding guide rail are arranged 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 move the left half iron core and the right half iron core along the sliding guide rail.

4. The laser additive manufacturing process auxiliary magnetic field application device according to claim 1, characterized in that: The horizontal auxiliary magnetic field application guiding device is a metal sheet. One metal sheet is respectively arranged at the bottom of the left half iron core and the bottom of the right half iron core, and the two metal sheets are parallel to each other.

5. 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.

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

7. 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.

8. The working method of the laser additive manufacturing process auxiliary magnetic field application device according to any one of claims 1 to 7, 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 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, and at the same time, the horizontal auxiliary magnetic field applying device and the vertical auxiliary magnetic field applying device apply vertical and horizontal magnetic fields to the workpiece.

9. The working method of the laser additive manufacturing process auxiliary magnetic field application device according to claim 8, characterized in that: The clamping device is a rotating device that drives the workpiece to be processed to rotate.

10. The working method of the laser additive manufacturing process auxiliary magnetic field application device according to claim 8, characterized in that: The telescopic movable arm can move along the axis to be processed as a whole with the auxiliary magnetic field application device of the laser additive manufacturing process.

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