A laminated magnetic field generating device

Abstract

A magnetic field generating device, comprising an arched magnetic core, a laser head, and a powder feeding mechanism. A magnetic supply coil is wound around the arched magnetic core, and the magnetic supply coil is connected to a power source. The arched magnetic core has an arched body, and each end of the arched magnetic core is connected to an adjustable magnetic pole head. A space for placing a workpiece is formed between the ends of the two adjustable magnetic pole heads. The adjustable magnetic pole head is formed by stacking multiple magnetic laminations. The adjustable magnetic pole head is provided with a through hole, and an adjusting screw engages with a threaded hole at the end of the arched magnetic core through the through hole. The adjusting screw constitutes the rotation pivot of the adjustable magnetic pole head and also constitutes the rotation pivot of the magnetic laminations in the adjustable magnetic pole head. By adjusting the positions of the magnetic laminations of the adjustable magnetic pole head, the present invention adjusts the magnetic field range, direction, and gradient, realizes electromagnetic field-assisted laser processing for parts of various sizes, various magnetic field directions, and gradient requirements, improves the mechanical properties of the parts to be processed, reduces defects such as pores in the laser processing process, adjusts the distribution of solute elements or hard phases, and improves the surface morphology of the cladding layer.

Description

Technical Field

[0001] The present invention relates to a magnetic field generating device for laser processing. Background Art

[0002] Laser processing technology has the advantages of high precision, high economic efficiency, strong controllability, etc., and is widely used in the processes of part strengthening and part repair. However, during the laser processing process, the molten pool undergoes a rapid heating and cooling process. At the same time, due to the differences in thermophysical properties between the part substrate material and the strengthening powder, defects such as cracks and pores are easily formed in the laser processing area.

[0003] In view of the above problems in laser processing, some scholars have proposed a method of assisting laser processing with an externally applied electromagnetic field. By applying the required electromagnetic field in the molten pool, a corresponding Lorentz force is formed in the laser molten pool to regulate the flow of the molten pool melt and reduce the defects inside the solidified structure.

[0004] Chinese Patent with Application No. 201720283134.8 discloses an experimental device for magnetic field assisted laser sintering. By applying magnetic field assistance during the laser sintering process, oxidation of the laser processed product is prevented, residues on the product surface are avoided, and the product quality is improved.

[0005] Chinese Patent with Application No. 201710282347.3 discloses a laser cladding device and method for removing pores / inclusions in a laser cladding layer. By applying an alternating magnetic field during the laser cladding process, the pores and non-metallic inclusions in the aluminum alloy laser cladding layer can be effectively reduced, and the quality of the laser cladding layer is significantly improved.

[0006] Chinese Patent with Application No. 201711070111.X discloses a general electric and magnetic composite field laser cladding assisting device and method with free wildcards. By applying electric and magnetic fields in different combination ways to generate different types of Lorentz forces and control the convection of the molten metal, conditions are provided for preparing excellent cladding layers in laser cladding.

[0007] However, the magnetic field ranges generated by the single magnetic field or electromagnetic field assisted laser manufacturing devices disclosed in the above patents are all fixed and non-adjustable, and the same set of devices cannot be used for processing and manufacturing parts of different sizes. In addition, the magnetic field direction and magnetic field distribution gradient of these devices are also non-adjustable, and it is impossible to flexibly and conveniently control the Lorentz force of the molten pool. Summary of the Invention

[0008] In view of the above defects of the prior art, the present invention provides a magnetic field generating device with an adjustable laminated magnetic field range, direction, gradient, and magnitude.

[0009] The present invention can adjust and control the magnetic field range, direction, gradient, and magnitude according to the requirements of the laser processed parts, thereby controlling the convective behavior of the molten pool and improving the comprehensive mechanical properties of the laser processed parts.

[0010] The magnetic field generating device of the present invention includes an arched magnetic core 5, a laser head 1, and a powder feeding mechanism. A magnetic supply coil 4 is wound around the arched magnetic core 5, and the magnetic supply coil 4 is connected to a power supply. It is characterized in that: the arched magnetic core 5 has an arched body, and each end of the arched magnetic core 5 is connected to an adjustable magnetic pole head 6, and a space for placing a workpiece 2 is formed between the ends of the two adjustable magnetic pole heads 6; the adjustable magnetic pole head 6 is formed by stacking multiple magnetic laminations, and the adjustable magnetic pole head is provided with a through hole, and an adjusting screw 7 engages with a threaded hole at the end of the arched magnetic core 5 through the through hole; the adjusting screw 7 constitutes the rotation pivot of the adjustable magnetic pole head 6 and also constitutes the rotation pivot of the magnetic laminations in the adjustable magnetic pole head 6.

[0011] The arched magnetic core 5 is composed of a transverse magnetic strip 501 with equal width and two longitudinal magnetic strips 502. The longitudinal magnetic strips 502 are arranged on the upper surfaces at the left and right ends of the transverse magnetic strip 501; the transverse magnetic strip 501 and the longitudinal magnetic strips 502 are both formed by stamping magnetic laminations. The top of the longitudinal magnetic strip 502 forms the end of the arched magnetic core 5, and the transverse magnetic strip 501 forms the bottom edge of the arched magnetic core 5.

[0012] The laser head is coaxially provided with three powder feeding head pipes, and the powder spot focus where the three powder beams converge coincides with the laser focus.

[0013] The carrier table crosses through the arched magnetic pole, and the workpiece to be laser processed is placed on the surface of the carrier table.

[0014] The magnetic supply coil is sleeved on the bottom edge of the arched magnetic core, and the positive and negative poles of the magnetic supply coil are connected to both ends of the power supply.

[0015] Further, the specific material of the magnetic laminations is silicon steel, and each magnetic lamination is coated with an insulating material.

[0016] Further, the coil can be made of copper wire winding or copper pipe winding.

[0017] Further, the power supply can be a DC power supply, an AC power supply, or a pulse power supply, so as to generate corresponding steady magnetic fields, alternating magnetic fields, and pulse magnetic fields.

[0018] Further, the vertical height of the adjustable magnetic pole head is 30 mm, and the distance between the two adjustable magnetic pole heads is 50 mm.

[0019] Further, each magnetic lamination of the adjustable magnetic pole head can move relative to each other, and the range of the rotatable angle of each magnetic lamination is ±60°.

[0020] Further, the workpiece to be processed is located between two adjustable magnetic pole heads. The focus of the laser beam is located on the surface of the workpiece to be processed.

[0021] The present invention has the following advantages:

[0022] 1. The adjustable magnetic poles as a whole can be rotated at a certain angle, so as to control the magnetic field direction and generate Lorentz forces in different directions to regulate the flow of the molten pool.

[0023] 2. The magnetic laminations of the adjustable magnetic poles can be spread out, so as to increase the size of the magnetic field action area and perform laser processing on parts with different sizes. One machine can be used for multiple purposes.

[0024] 3. The magnetic laminations of the adjustable magnetic poles can be spread out at any overlapping rate, and the change of the magnetic field gradient can be controlled, so as to realize the distribution of different magnetic field sizes in different regions, which is more flexible and controllable. Description of the Drawings

[0025] Figure 1 It is a schematic structural diagram of Embodiment 1 of the present invention.

[0026] Figure 2 It is a schematic structural diagram of Embodiment 2 of the present invention.

[0027] Figure 3 It is a schematic structural diagram of Embodiment 3 of the present invention.

[0028] Figure 4 It is a schematic structural diagram of Embodiment 4 of the present invention. Detailed Embodiments

[0029] The present invention will be further described below in conjunction with the drawings and embodiments.

[0030] A magnetic field generating device with adjustable magnetic field range, direction, gradient and magnitude of a laminated type according to the present invention includes a laser head 1, a workpiece 2, a carrier table 3, an arched magnetic core 5, adjustable magnetic pole heads 6, adjusting screws 7, a magnetic supply coil 4 and a power source.

[0031] The laser head 1 is coaxially provided with three powder feeding head pipes, and the powder spot focus where the three powder beams converge coincides with the laser focus.

[0032] The arched magnetic core 5 is composed of a transverse magnetic strip 501 with the same width and two longitudinal magnetic strips 502, and the longitudinal magnetic strips 502 are fixedly arranged on the upper surfaces of the left and right ends of the transverse magnetic strip 501. The transverse magnetic strip 501 and the longitudinal magnetic strips 502 are both stamped from magnetic laminations, and threaded holes are opened at the tops of the two longitudinal magnetic strips 502.

[0033] The adjustable magnetic pole head 6 is composed of multiple magnetic laminations. There are two through holes at both ends of the left and right adjustable pole heads 6. The adjusting screw 7 is matched with the threaded hole on the longitudinal magnetic strip 502 through the through hole on the adjustable magnetic pole head 6.

[0034] The stage 3 horizontally passes through the arched magnetic core 5, and the workpiece 2 to be laser processed is placed on the surface of the stage 3.

[0035] The magnetic supply coil 4 is sleeved on the transverse magnetic strip 501, and the positive and negative poles of the magnetic supply coil 4 are connected to both ends of the power supply.

[0036] The specific material of the magnetic lamination is silicon steel, and each magnetic lamination is coated with an insulating material.

[0037] The magnetic supply coil 4 is made of copper wire winding or copper tube winding.

[0038] The power supply can be a DC power supply, an AC power supply, or a pulse power supply, so as to generate corresponding steady magnetic fields, alternating magnetic fields, and pulse magnetic fields.

[0039] The height of the adjustable magnetic pole head 6 is 30 mm, and the distance between the two adjustable magnetic pole heads 6 is 50 mm.

[0040] Relative movement can be achieved between each magnetic lamination of the adjustable magnetic pole head 6, and the range of the rotatable angle of each magnetic lamination is ±60°.

[0041] The workpiece to be processed is located between the two adjustable magnetic pole heads 6. The focus of the laser beam is located on the surface of the workpiece 2 to be processed.

[0042] The usage method of the present invention is as follows:

[0043] (1) Grind, clean, and dry the surface of the part to be processed, and place it on the surface of the stage.

[0044] (2) Adjust the positions of the magnetic laminations of the two adjustable magnetic pole heads. After generating the magnetic field with the required distribution, tighten the adjusting screw

[0045] (3) Turn on the power supply and adjust the current frequency and current magnitude in the magnetic supply coil

[0046] (4) Select appropriate laser process parameters, turn on the laser to irradiate the surface of the part to be repaired, and at the same time feed metal powder through the powder feeder

[0047] (5) Turn off the laser and the power supply, and the part processing is completed.

[0048] Embodiment 1

[0049] Refer to the appendix Figure 1, this example is a conventional part repair and machining example (the laser scanning direction is perpendicular to the magnetic field direction). In this example, first, the area to be repaired of part 2 is polished with sandpaper, and then the workpiece 2 is cleaned with anhydrous ethanol or acetone to remove oil stains, and is naturally air-dried or dried with a hair dryer. The pre-treated part 2 is placed on the stage 3. Then, the alloy powder is placed in a drying oven and dried at 120 °C for 1 h. After cooling, it is added to the powder feeder. Next, adjust the positions of the magnetic laminations of the two adjustable magnetic pole heads 6 so that the magnetic laminations are on the same vertical line, and the axes of the two adjustable magnetic pole heads 6 are on the same horizontal line. After adjustment, tighten the adjustment screw 7. Then, turn on the power switch and adjust the current frequency and magnitude in the magnetic supply coil 4. Select appropriate laser process parameters, turn on the laser so that the laser beam irradiates the surface of the part 2 to be repaired, and at the same time send the dried metal powder through the powder feeder. Finally, turn off the laser and the power supply, and the part machining is completed. Example 2

[0050] Refer to the appendix Figure 2 , this example is a part repair and machining example at a non-vertical angle. The device is the same as in Example 1. The difference between this example and Example 1 lies in the adjustment of the adjustable magnetic pole heads 6. Specifically, adjust the positions of the magnetic laminations of the two adjustable magnetic pole heads 6 so that the magnetic laminations are on the same vertical line, and the two adjustable magnetic pole heads 6 are staggered at the required angle. After adjustment, tighten the adjustment screw 7. Example 3

[0051] Refer to the appendix Figure 3 , this example is a large part repair and machining example. The device is the same as in Example 1. The difference between this example and Example 1 lies in the adjustment of the adjustable magnetic pole heads 6. Specifically, adjust the positions of the magnetic laminations of the two adjustable magnetic pole heads 6 so that the magnetic laminations are fan-shaped and spread out at the same angle (the overlapping area of each magnetic lamination is the same), and the axes of the two adjustable magnetic pole heads 6 are on the same horizontal line. After adjustment, tighten the adjustment screw 7. Example 4

[0052] Refer to the appendix Figure 4 , this example is a part repair and machining example under a gradient magnetic field distribution. The device is the same as in Example 1. The difference between this example and Example 1 lies in the adjustment of the adjustable magnetic pole heads 6. Specifically, adjust the positions of the magnetic laminations of the two adjustable magnetic pole heads 6 so that the magnetic laminations are fan-shaped and spread out at different angles (the overlapping area of each magnetic lamination is different), and the axes of the two adjustable magnetic pole heads 6 are on the same horizontal line. After adjustment, tighten the adjustment screw 7.

[0053] The present invention controls the magnetic field range, direction, and gradient by adjusting the positions of the magnetic laminations of the adjustable magnetic pole head, thereby realizing the electromagnetic field-assisted laser processing technology for parts of various sizes, various magnetic field directions, and gradient requirements, achieving the purposes of improving the mechanical properties of the parts to be processed, reducing defects such as pores in the laser processing process, adjusting the distribution of solute elements or hard phases, and improving the surface morphology of the cladding layer. The present invention has the characteristics of flexible adjustability, simple operation, and a wide range of processable parts.

[0054] The content described in the embodiments of this specification is only a list of the implementation forms of the inventive concept. The protection scope of the present invention should not be regarded as limited to the specific forms stated in the embodiments. The protection scope of the present invention also includes equivalent technical means that those skilled in the art can think of based on the inventive concept.

Claims

1. A magnetic field generating device, comprising an arched magnetic core (5), a laser head (1), and a powder feeding mechanism. A magnetic supply coil (4) is wound around the arched magnetic core (5), and the magnetic supply coil (4) is connected to a power source. It is characterized in that: The arched magnetic core (5) has an arched body, and an adjustable magnetic pole head (6) is connected to each end of the arched magnetic core (5). A space for placing a workpiece (2) is formed between the ends of the two adjustable magnetic pole heads (6); the adjustable magnetic pole head (6) is formed by stacking multiple magnetic laminations. The adjustable magnetic pole head is provided with a through hole, and an adjusting screw (7) meshes with a threaded hole at the end of the arched magnetic core (5) through the through hole; the adjusting screw (7) constitutes the rotation pivot of the adjustable magnetic pole head (6) and also constitutes the rotation pivot of the magnetic laminations in the adjustable magnetic pole head (6).

2. The magnetic field generating device according to claim 1, wherein: The arched magnetic core (5) is composed of a transverse magnetic strip (501) with equal width and two longitudinal magnetic strips (502). The longitudinal magnetic strips (502) are arranged on the upper surfaces at the left and right ends of the transverse magnetic strip (501); the transverse magnetic strip (501) and the longitudinal magnetic strips (502) are both formed by stamping magnetic laminations. The top of the longitudinal magnetic strip (502) forms the end of the arched magnetic core (5), and the transverse magnetic strip (501) forms the bottom edge of the arched magnetic core (5).

3. The magnetic field generating device according to claim 1, wherein: The specific material of the magnetic laminations is silicon steel, and each magnetic lamination is coated with an insulating material.

4. The magnetic field generating device according to claim 1, wherein: The power supply is a DC power supply, or an AC power supply, or a pulse power supply.

5. The magnetic field generating device according to claim 1, wherein: The vertical height of the adjustable magnetic pole head is 30 mm, the distance between the two adjustable magnetic pole heads is 50 mm, and the range of the rotatable angle of each magnetic lamination is ±60°.

Images