A sintered permanent magnet, an oxygen control device for preparing the sintered permanent magnet, and a method of using it.

Abstract

This invention relates to the field of permanent magnet manufacturing technology, and discloses a sintered permanent magnet, an oxygen control device for sintered permanent magnet manufacturing, and a method for using it. The sintered permanent magnet has excellent corrosion resistance and wear resistance, effectively extending the service life of the permanent magnet. The oxygen supplementer is equipped with a cleaner, a homogenizer, and a gradient oxygen controller from top to bottom. The gradient oxygen controller is equipped with a flow guide. During oxygen control, the transfer of magnetic powder particles is completed in a fully enclosed manner. The cleaner forms a vortex airflow to clean the magnetic powder particles, facilitating the removal of residual oxygen between particles. The plasma generated by the homogenizer can reduce the surface of the magnetic powder particles and eliminate electrostatic agglomeration, ensuring good consistency of the magnetic powder particles during oxidation. The gradient oxygen controller forms oxygen content layers of different levels, oxidizing the magnetic powder surface to form a dense alumina film, solving the problem of inconsistent oxidation of fine magnetic powder, and is particularly suitable for the preparation of sintered NdFeB.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet preparation technology, and particularly to a sintered permanent magnet, an oxygen control device for preparing sintered permanent magnets, and a method for using them. Background Technology

[0002] Neodymium iron boron (NdFeB) is currently the strongest rare-earth permanent magnet material, possessing high magnetic energy product, good coercivity, and high temperature resistance. Currently, oxygen is added during the air jet milling process, and oxygen is controlled through isolation in subsequent production to achieve oxygen control. However, it is difficult to control the particle size of the coarse powder during air jet milling, and the residence time of the coarse powder in the milling chamber directly determines the amount of oxygen absorbed by the magnetic powder, thus affecting the coercivity of the final NdFeB permanent magnet.

[0003] An oxygen control device for sintering neodymium iron boron permanent magnets, application number CN202211267162.2, controls the magnetic force of an electromagnetic chuck, causing the magnetic force of the chuck to gradually decrease. High-quality magnetic powder particles initially adsorbed on the chuck first detach from the chuck and fall onto a rotating screen. Particles smaller than the screen mesh pass through the screen and fall into the separating fiber clusters, while particles larger than the screen mesh roll into the accumulation end. The magnetic powder falls into the separating fiber clusters sequentially according to its weight and volume, without affecting each other. Finally, the magnetic powder particles that meet the size requirements are oxidized in the isolated spaces within the separating fiber clusters. This device achieves oxygen supplementation by separating the magnetic powder particles according to their size.

[0004] However, in the actual oxygen control process, the small magnetic powder particles filtered by the sieve accumulate inside the separating fiber clusters. Because the magnetic powder particles are piled up together, they cannot come into full and uniform contact with oxygen, making it difficult to guarantee the consistency of oxidation of the magnetic powder particles. Although the uniform oxygen supply method improves the coercivity of the magnet after molding to a certain extent, the large differences in the size and specific surface area of ​​the magnetic powder make it difficult to guarantee the degree of oxidation between the magnetic powder particles when oxygen is supplied uniformly, thus affecting the final oxygen supply effect.

[0005] Therefore, this invention proposes a sintered permanent magnet, an oxygen control device for preparing the sintered permanent magnet, and a method for using it to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a sintered permanent magnet, an oxygen control device for preparing a sintered permanent magnet, and a method for using it, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a sintered permanent magnet, comprising a permanent magnet substrate, wherein an epoxy film layer is stacked on the surface of the permanent magnet substrate, a conductive resin film layer is stacked on the surface of the epoxy film layer, and an anti-oxidation layer is stacked on the surface of the conductive resin film layer.

[0008] This invention provides an oxygen control device for the preparation of sintered permanent magnets, including an oxygen supplementer, wherein a cleaner, a feed homogenizer, and a gradient oxygen controller are sequentially assembled from top to bottom inside the oxygen supplementer;

[0009] The cleaner includes multiple sets of angled jet nozzles with the same inclination, and the multiple sets of angled jet nozzles are combined to form a gas jet ring;

[0010] The homogenizer includes two sets of parallel electrode plates, with a dispersion disk assembled between the two sets of electrode plates. A gas distribution ring is fixed on the inner wall of the homogenizer, and a flow guide corresponding to the gradient oxygen controller is synchronously installed below the dispersion disk.

[0011] The gradient oxygen controller includes a diamond-shaped oxygen control layer, a circular oxygen control layer, and a strip-shaped oxygen control layer arranged from top to bottom inside the oxygen supplementer, and each of the diamond-shaped oxygen control layer, the circular oxygen control layer, and the strip-shaped oxygen control layer is equipped with a piezoelectric micro-valve.

[0012] Preferably, the oxygenator has a cleaning chamber, an activation chamber and a passivation chamber arranged sequentially from top to bottom inside. The top of the oxygenator is provided with a feed hopper, the bottom outer edge of the oxygenator is fixed with a support, and the top of the oxygenator is provided with an electrical control box.

[0013] Preferably, the cleaner is installed in the cleaning chamber, and the cleaner has a vortex guide trough. Multiple sets of oblique jet nozzles are evenly distributed in the vortex guide trough. A discharge channel is connected between the cleaning chamber and the activation chamber, and a discharge valve is fixedly installed in the discharge channel.

[0014] Preferably, the uniform feeder is disposed in the activation chamber, and the uniform feeder also includes a rotating shaft. The top end of the rotating shaft is connected to a dispersing disk. The dispersing disk is provided with uniform feed holes evenly distributed. An arc-shaped seat is provided at the bottom of the activation chamber. A feed hole is connected between the activation chamber and the passivation chamber, and a guide valve is installed in the feed hole.

[0015] Preferably, the top of the activation chamber is provided with an annular storage groove, the top of the dispersion disc is integrally formed with a sealing ring that matches the annular storage groove, multiple sets of gas storage bags are uniformly fixed in the annular storage groove on the side away from the opening, and pressure-bearing protrusions are uniformly fixed in the top of the sealing ring.

[0016] Preferably, the bottom of the passivation chamber is provided with a discharge port, a discharge valve is installed in the discharge port, the drainer is set in the passivation chamber, the bottom end of the rotating shaft extends into the passivation chamber and is fixedly connected to a motor, and the drainer is fixedly sleeved on the outer wall of the rotating shaft.

[0017] Preferably, the drainage device includes a drainage cover, the outer edge of which is hinged to a plurality of sets of swing plates arranged in a circular array, and an elastic cloth is fixedly connected between adjacent sets of swing plates and the drainage cover. A protective cover is connected to the drainage cover at the corresponding position of the swing plate, and the protective cover is fixedly connected to the elastic cloth. Each set of swing plates and the bottom of the drainage cover are connected by a driving component.

[0018] Preferably, the driving component includes an inner guide cylinder fixed to the bottom of the swing plate and an outer guide cylinder fixed to the bottom of the drainage hood. Both the inner and outer guide cylinders are configured as arc-shaped cylinders with the hinge axis as the center. The inner guide cylinder is slidably assembled inside the outer guide cylinder. A driving airbag is installed between the inner and outer guide cylinders, and the driving airbag is connected to the air storage bag through an air guide pipe.

[0019] This invention provides a method for using an oxygen control device prepared from sintered permanent magnets, comprising the following steps:

[0020] S1: The magnetic powder is introduced into the oxygenator. First, the magnetic powder accumulates inside the cleaner. The airflow ejected by multiple sets of oblique jet nozzles forms a spiral airflow field inside the cleaner, driving the magnetic powder to form a vortex and quickly stripping the adsorbed oxygen from the surface of the magnetic powder particles.

[0021] S2: After the magnetic powder cleaning is completed, the magnetic powder particles enter the homogenizer. The electrode plate generates uniform plasma to reduce the surface oxides. The dispersion disk rotates, so that the magnetic powder particles are evenly distributed in the dispersion disk. The mechanical agglomeration is broken up and the fresh surface of the magnetic powder is exposed. The gas distribution ring introduces protective gas into the homogenizer, so that the protective gas evenly covers the surface of the magnetic powder.

[0022] S3: After the magnetic powder surface is activated, the magnetic powder is introduced into the gradient oxygen controller. Under the action of the guide, the magnetic powder is evenly dispersed inside the gradient oxygen controller. The different opening ratios of the rhomboid, circular, and strip-shaped oxygen control layers create oxygen gradients of different orders of magnitude from top to bottom inside the gradient oxygen controller, completing the surface passivation of the magnetic powder, improving its oxidation resistance and magnetic properties, and finally being discharged.

[0023] The technical effects and advantages of this invention are as follows:

[0024] 1. This invention employs a fully enclosed process to transfer magnetic powder particles during oxygen control. The cleaner generates a vortex airflow to clean the magnetic powder particles, facilitating the removal of residual oxygen between particles and achieving the purpose of pretreatment oxygen control. Meanwhile, the plasma generated by the homogenizer can reduce the surface of the magnetic powder particles and eliminate electrostatic agglomeration, ensuring good consistency of the magnetic powder particles during oxidation. The gradient oxygen controller forms oxygen content layers of different levels, oxidizing the magnetic powder surface to form a dense alumina film, solving the problem of inconsistent oxidation of fine magnetic powder, and is particularly suitable for the preparation of high-performance sintered NdFeB.

[0025] 2. In the oxygen control operation, the use of the feeder in conjunction with the flow guide causes the swing plate to swing back and forth, thereby driving the magnetic powder particles dispersed on the flow guide hood, increasing the dispersion effect of the magnetic powder in the passivation chamber. When the swing plate swings upward, it can drive the magnetic powder to move upward, causing the magnetic powder and falling magnetic powder to impact each other, increasing the dispersion between the magnetic powder, preventing particle agglomeration, and enhancing the particle circulation volume. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the overall internal structure of the present invention;

[0028] Figure 3 This is a schematic diagram of the cleaner structure of the present invention;

[0029] Figure 4 This is a schematic diagram of the material equalizer structure of the present invention;

[0030] Figure 5 This is a schematic diagram of the drainage device structure of the present invention;

[0031] Figure 6 This is a cross-sectional structural diagram of the oxygen supplementation chamber of the present invention.

[0032] In the diagram: 10. Aerator; 11. Feed hopper; 12. Cleaning chamber; 13. Activation chamber; 14. Passivation chamber; 15. Support; 16. Electrical control box; 20. Cleaner; 21. Vortex feed chute; 22. Inclined jet nozzle; 23. Feeding channel; 24. Feeding valve; 30. Feeder; 31. Electrode plate; 32. Rotating shaft; 33. Motor; 34. Dispersion disc; 35. Encapsulation ring; 36. Arc-shaped seat; 37. 38. Feed distribution hole; 39. Feed guide valve; 30. Annular receiving trough; 310. Gas storage bag; 311. Pressure bearing boss; 40. Gradient oxygen controller; 41. Diamond-shaped oxygen control layer; 42. Circular oxygen control layer; 43. Strip-shaped oxygen control layer; 44. Discharge port; 45. Discharge valve; 50. Flow guide; 51. Flow guide hood; 52. Swing plate; 53. Elastic cloth; 54. Protective cover; 55. Inner guide cylinder; 56. Outer guide cylinder. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0034] Example 1:

[0035] This embodiment discloses a sintered permanent magnet, including a permanent magnet substrate. An epoxy film layer is stacked on the surface of the permanent magnet substrate, a conductive resin film layer is stacked on the surface of the epoxy film layer, and an anti-oxidation layer is stacked on the surface of the conductive resin film layer. After the permanent magnet is sintered, the epoxy film layer can improve the loss of the permanent magnet caused by the magnetic eddy current phenomenon generated during the use of the permanent magnet. The conductive resin film layer solves the problem of the epoxy film layer having high resistance and being unfavorable for the formation of an anti-oxidation layer. The anti-oxidation layer on the surface of the sintered permanent magnet has excellent anti-corrosion and wear resistance properties, effectively extending the service life of the permanent magnet.

[0036] Example 2:

[0037] like Figures 1 to 6 As shown, this embodiment discloses an oxygen control device for the preparation of sintered permanent magnets, including an oxygen supplementer 10. The oxygen supplementer 10 is equipped with a cleaner 20, a homogenizer 30, and a gradient oxygen controller 40 from top to bottom. During oxygen control, the transfer of magnetic powder particles is completed in a fully enclosed manner. The cleaner 20 forms a vortex airflow to clean the magnetic powder particles, which facilitates the removal of residual oxygen between particles and achieves the purpose of pretreatment oxygen control. The plasma generated by the homogenizer 30 can reduce the surface of the magnetic powder particles and eliminate electrostatic agglomeration, which facilitates good consistency of the magnetic powder particles during oxidation. The gradient oxygen controller 40 forms oxygen content layers of different levels and oxidizes the magnetic powder surface to form a dense alumina film, which solves the problem of inconsistent oxidation of fine magnetic powder. It is especially suitable for the preparation of high-performance sintered NdFeB magnets.

[0038] Specifically, please refer to Figure 1 and Figure 2The oxygenator 10 has a cleaning chamber 12, an activation chamber 13, and a passivation chamber 14 arranged sequentially from top to bottom. A feed hopper 11 is provided at the top of the oxygenator 10, and a sealing cover is installed on the feed hopper 11. A support 15 is fixed to the outer edge of the bottom of the oxygenator 10. An electrical control box 16 is provided at the top of the oxygenator 10, which divides the interior of the oxygenator 10 into three reaction chambers. This allows the magnetic powder particles to enter the interior of the oxygenator 10 through the sealing cover, thus achieving zero atmospheric exposure of the magnetic powder and facilitating the oxygen control operation of the magnetic powder particles. The electrical control box 16 provides integrated control of the oxygenator 10.

[0039] Please see Figure 2 and Figure 3 The cleaner 20 includes multiple sets of angled jet nozzles 22 with the same inclination. The multiple sets of angled jet nozzles 22 are combined to form a gas jet ring. The cleaner 20 is set in the cleaning chamber 12. The cleaner 20 has a vortex guide groove 21. The multiple sets of angled jet nozzles 22 are evenly distributed in the vortex guide groove 21. A feeding channel 23 is connected between the cleaning chamber 12 and the activation chamber 13. A feeding valve 24 is fixedly installed in the feeding channel 23. The angled jet nozzles 22 are evenly arranged inside the vortex guide groove 21 and form a spaced jet ring. The airflow they spray forms a spiral airflow field, which makes the magnetic powder form a vortex in the vortex guide groove 21. This facilitates the removal of adsorbed oxygen on the surface of the magnetic powder particles. Moreover, the vortex-shaped airflow can prevent the magnetic powder particles from accumulating, allowing the airflow to penetrate into the magnetic powder particles and improve the pretreatment capability of the magnetic powder particle surface.

[0040] It should be noted that the oxygenator 10 is also equipped with a vacuum pumping module that matches the vortex guide trough 21. Before the magnetic powder particles are introduced into the cleaning chamber 12 through the feed hopper 11, the vacuum pumping module is used to evacuate the cleaning chamber 12, which can quickly remove free oxygen molecules.

[0041] Please see Figure 2 and Figure 4 The homogenizer 30 includes two sets of parallel electrode plates 31. When the electrode plates 31 are working, they generate uniform plasma to reduce the oxides on the surface of the magnetic powder particles. A dispersion disk 34 is assembled between the two sets of electrode plates 31. A gas distribution ring is fixed on the inner wall of the homogenizer 30. The gas distribution ring is a porous ceramic ring with a pore diameter of 0.5 mm. A flow guide 50 corresponding to the gradient oxygen controller 40 is synchronously driven and installed below the dispersion disk 34. The homogenizer 30 is set in the activation chamber 13. The homogenizer 30 also includes a rotating shaft 32. The top end of the rotating shaft 32 is connected to the dispersion disk 34. The bottom end of the rotating shaft 32 extends to the passivation chamber 14 and is fixedly connected to a motor 33. Homogenizing holes 37 are uniformly opened on the dispersion disk 34. An arc-shaped seat 36 is set at the bottom of the activation chamber 13. A discharge hole is connected between the activation chamber 13 and the passivation chamber 14, and a guide valve 38 is assembled in the discharge hole.

[0042] In actual use, after the magnetic powder particles have been cleaned by the cleaner 20, the discharge valve 24 is opened, and the magnetic powder particles inside the cleaner 20 are introduced into the dispersing disc 34 through the discharge channel 23. Then the discharge valve 24 is closed. At the same time, the motor 33 drives the dispersing disc 34 to rotate through the rotating shaft 32. The dispersing disc 34 drives the magnetic powder particles inside to be evenly dispersed, so that the magnetic powder particles are evenly distributed in the dispersing disc 34. The friction between the dispersing disc 34 and the magnetic powder particles when rotating achieves the purpose of mechanically breaking down the agglomerates of the magnetic powder particles, making it easier to expose the fresh surface of the magnetic powder. The gas distribution circumferential feeder 30 introduces protective gas to ensure that the protective gas is evenly distributed in the activation chamber 13. The protective gas is an Ar / H2 mixed gas with a ratio of 95%:5%, so that the protective gas evenly covers the surface of the magnetic powder, which serves to protect the surface of the magnetic powder particles. It can reduce the already oxidized surface of the magnetic powder and prevent further oxidation of the magnetic powder surface under the action of the protective gas.

[0043] Please see Figure 2 and Figure 6 The gradient oxygen controller 40 includes a diamond-shaped oxygen control layer 41, a circular oxygen control layer 42, and a strip-shaped oxygen control layer 43 arranged from top to bottom inside the oxygen supplementer 10. Each of the diamond-shaped oxygen control layer 41, the circular oxygen control layer 42, and the strip-shaped oxygen control layer 43 is equipped with a piezoelectric microvalve. Each of the diamond-shaped oxygen control layer 41, the circular oxygen control layer 42, and the strip-shaped oxygen control layer 43 is equipped with an oxygen sensor, which can monitor the oxygen content inside the passivation chamber 14 in real time. Based on the real-time oxygen concentration feedback, the opening of the piezoelectric microvalve is adjusted to make the oxygen partial pressure gradient deviation < ±5%.

[0044] Meanwhile, a micro-atomizing nozzle is also provided in the passivation chamber 14, which can introduce Ar gas containing 0.1-0.5% silane into the passivation chamber 14, so that the magnetic powder particles can form a Si-O-Nd surface protective layer in the passivation chamber 14 and improve the oxidation resistance. A discharge port 44 is opened at the bottom of the passivation chamber 14, and a discharge valve 45 is installed in the discharge port 44. The flow guide 50 is set in the passivation chamber 14 and is fixedly sleeved on the outer wall of the rotating shaft 32.

[0045] After the magnetic powder particles are activated, the feed valve 38 is opened. As the dispersing disc 34 rotates, the magnetic powder falls through the equalization holes 37 on its surface, completing the sieving of the magnetic powder particles and improving the particle size consistency during downward transfer. After all the magnetic powder has fallen into the passivation chamber 14, the feed valve 38 is closed. Simultaneously, the motor 33 drives the guide 50 to rotate via the shaft 32, guiding the magnetic powder particles falling from the feed valve 38. Furthermore, the rotation of the guide 50 disperses the magnetic powder, ensuring it is evenly distributed within the passivation chamber 14 during its descent. The rhomboid oxygen control layer 41 and the circular... The different opening ratios of the perforated oxygen control layer 42 and the strip-shaped perforated oxygen control layer 43 create oxygen gradients of different orders of magnitude from top to bottom inside the gradient oxygen controller 40. This allows the magnetic powder particles to pass through different oxygen gradients sequentially, achieving the oxidation operation of the magnetic powder. Moreover, the oxidation operation under different oxygen gradients can precisely control the oxidation rate of the magnetic powder through precise oxygen control, preventing over-oxidation of the magnetic powder and breaking through the oxygen control bottleneck of traditional uniform porous plates. After the gradient oxygen controller 40 passesivates the surface of the magnetic powder, it can improve the oxidation resistance and magnetic properties of the magnetic powder particles. After the magnetic powder particles have been oxidized, the discharge valve 45 is opened, allowing the magnetic powder to be discharged from the discharge port 44.

[0046] Please note that you should refer to [link / reference]. Figure 2 and Figure 4 The activation chamber 13 has an annular storage groove 39 at its top. The top of the dispersion disc 34 is integrally formed with a sealing ring 35 that matches the annular storage groove 39. Multiple sets of gas storage bags 310 are evenly fixed on the side of the annular storage groove 39 away from the opening. Pressure-bearing protrusions 311 are evenly fixed on the top of the sealing ring 35. (Please refer to...) Figure 4 and Figure 5 The drainage device 50 includes a drainage cover 51. Multiple sets of swing plates 52 arranged in a circular array are hinged to the outer edge of the drainage cover 51 via a hinge shaft. An elastic cloth 53 is fixedly connected between two adjacent sets of swing plates 52 and the drainage cover 51. A protective cover 54 is connected to the drainage cover 51 at the corresponding position of the swing plate 52. The protective cover 54 and the elastic cloth 53 are fixedly connected. Each set of swing plates 52 and the bottom of the drainage cover 51 are connected by a driving component. The driving component includes an inner guide cylinder 55 fixed to the bottom of the swing plate 52 and an outer guide cylinder 56 fixed to the bottom of the drainage cover 51. The inner guide cylinder 55 and the outer guide cylinder 56 are both set as arc-shaped cylinders with the hinge shaft as the center. The inner guide cylinder 55 is slidably assembled inside the outer guide cylinder 56. A driving airbag is installed between the inner guide cylinder 55 and the outer guide cylinder 56. The driving airbag is connected to the air storage bag 310 through a duct.

[0047] During the operation of the equalizer 30, it synchronously drives the guide 50 to rotate, and the equalizer 30 can drive the guide 50 to oscillate back and forth to increase the dispersion of magnetic powder particles, specifically:

[0048] During the process of magnetic powder particles being introduced from the feed valve 38 into the passivation chamber 14, the magnetic powder particles first fall onto the surface of the guide hood 51. As the guide hood 51 rotates, centrifugal force is used to evenly disperse the magnetic powder into the passivation chamber 14. Moreover, during the rotation of the dispersion disk 34, the pressure-bearing protrusion 311 on the top of the sealing ring 35 rotates synchronously. The sealing ring 35 blocks the magnetic powder particles, preventing them from entering the annular receiving groove 39. The pressure-bearing protrusions 311 are spaced apart, so during the rotation of the pressure-bearing protrusions 311, they intermittently compress the gas storage bag 310. When the gas storage bag 310 is compressed, the gas inside it is introduced into the driving air bag through the air guide pipe, causing the driving air bag to expand and push the inner guide cylinder 55 from the outer guide. The cylinder 56 moves outward, thereby the inner guide cylinder 55 pushes the swing plate 52 to rotate upward around the hinge axis. When the pressure-bearing boss 311 and the air storage bag 310 are misaligned, the gas inside the driving airbag flows back to the air storage bag 310 through the air guide pipe. Then the swing plate 52 returns to its original position downward. With the reciprocating compression and misalignment of the pressure-bearing boss 311 and the air storage bag 310, the driving force and the resetting force of the swing plate 52 can be generated, so that the swing plate 52 swings back and forth, thereby driving the magnetic powder particles dispersed on the drainage cover 51, increasing the dispersion effect of the magnetic powder inside the passivation chamber 14. Moreover, when the swing plate 52 swings upward, it can drive the magnetic powder to move upward, so that the magnetic powder and the falling magnetic powder will impact each other, increasing the dispersion between the magnetic powder, preventing the particles from agglomerating, and enhancing the particle circulation volume.

[0049] Example 3:

[0050] This embodiment discloses a method for using an oxygen control device prepared from sintered permanent magnets, comprising the following steps:

[0051] S1: The magnetic powder is introduced into the oxygenator 10. First, the magnetic powder accumulates inside the cleaner 20. The airflow ejected by multiple sets of oblique jet nozzles 22 forms a spiral airflow field in the cleaner 20, which drives the magnetic powder to form a vortex and quickly peels off the adsorbed oxygen on the surface of the magnetic powder particles.

[0052] S2: After the magnetic powder cleaning is completed, the magnetic powder particles enter the homogenizer 30. The electrode plate 31 generates uniform plasma to reduce the surface oxides. The dispersion disk 34 rotates, so that the magnetic powder particles are evenly distributed in the dispersion disk 34, mechanically breaking up the agglomerates and exposing the fresh surface of the magnetic powder. The gas distribution ring introduces protective gas into the homogenizer 30, so that the protective gas evenly covers the surface of the magnetic powder.

[0053] S3: After the magnetic powder surface is activated, the magnetic powder is introduced into the gradient oxygen controller 40. Under the action of the guide 50, the magnetic powder is evenly dispersed inside the gradient oxygen controller 40. The different opening ratios of the rhomboid oxygen control layer 41, the circular oxygen control layer 42, and the strip-shaped oxygen control layer 43 create oxygen gradients of different orders of magnitude from top to bottom inside the gradient oxygen controller 40, completing the surface passivation of the magnetic powder, improving the oxidation resistance and magnetic properties of the magnetic powder, and finally discharging it.

[0054] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An oxygen control device prepared from sintered permanent magnets, characterized in that: It includes an oxygenator (10), which is equipped with a cleaner (20), a feeder (30) and a gradient oxygen controller (40) from top to bottom. The cleaner (20) includes multiple sets of angled jet nozzles (22) with the same inclination, and the multiple sets of angled jet nozzles (22) are combined to form a gas jet ring; The homogenizer (30) includes two sets of parallel electrode plates (31), and a dispersion disk (34) is assembled between the two sets of electrode plates (31). A gas distribution ring is fixed on the inner wall of the homogenizer (30), and a flow guide (50) corresponding to the gradient oxygen controller (40) is synchronously driven installed below the dispersion disk (34). The gradient oxygen controller (40) includes a rhomboid oxygen control layer (41), a circular oxygen control layer (42), and a strip-shaped oxygen control layer (43) arranged from top to bottom inside the oxygen supplementer (10), and each of the rhomboid oxygen control layer (41), the circular oxygen control layer (42), and the strip-shaped oxygen control layer (43) is equipped with a piezoelectric micro-valve.

2. The oxygen control device for preparing sintered permanent magnets according to claim 1, characterized in that: The oxygenator (10) has a cleaning chamber (12), an activation chamber (13) and a passivation chamber (14) arranged from top to bottom. The top of the oxygenator (10) is provided with a feed hopper (11), the bottom outer edge of the oxygenator (10) is fixed with a support (15), and the top of the oxygenator (10) is provided with an electrical control box (16).

3. The oxygen control device for preparing sintered permanent magnets according to claim 2, characterized in that: The cleaner (20) is installed in the cleaning chamber (12). The cleaner (20) is provided with a vortex guide trough (21). Multiple sets of oblique jet nozzles (22) are evenly distributed in the vortex guide trough (21). A discharge channel (23) is connected between the cleaning chamber (12) and the activation chamber (13). A discharge valve (24) is fixedly installed in the discharge channel (23).

4. The oxygen control device for preparing sintered permanent magnets according to claim 2, characterized in that: The equalizer (30) is located in the activation chamber (13). The equalizer (30) also includes a rotating shaft (32). The top end of the rotating shaft (32) is connected to the dispersing disk (34). The dispersing disk (34) is evenly provided with equalizing holes (37). An arc-shaped seat (36) is provided at the bottom of the activation chamber (13). A discharge hole is connected between the activation chamber (13) and the passivation chamber (14), and a guide valve (38) is installed in the discharge hole.

5. The oxygen control device for preparing sintered permanent magnets according to claim 4, characterized in that: The activation chamber (13) has an annular storage groove (39) at the top. The top of the dispersion plate (34) is integrally formed with a sealing ring (35) that matches the annular storage groove (39). Multiple sets of gas storage bags (310) are uniformly fixed on the side away from the opening in the annular storage groove (39). Pressure-bearing bosses (311) are uniformly fixed on the top of the sealing ring (35).

6. The oxygen control device for preparing sintered permanent magnets according to claim 5, characterized in that: The passivation chamber (14) has a discharge port (44) at the bottom, and a discharge valve (45) is installed in the discharge port (44). The drainer (50) is installed in the passivation chamber (14). The bottom end of the rotating shaft (32) extends to the passivation chamber (14) and is fixedly connected to a motor (33). The drainer (50) is fixedly sleeved on the outer wall of the rotating shaft (32).

7. The oxygen control device for preparing sintered permanent magnets according to claim 6, characterized in that: The drain device (50) includes a drain cover (51). Multiple sets of swing plates (52) arranged in a circular array are hinged to the outer edge of the drain cover (51) via a hinge shaft. An elastic cloth (53) is fixedly connected between two adjacent sets of swing plates (52) and the drain cover (51). A protective cover (54) is connected to the drain cover (51) at the corresponding position of the swing plate (52). The protective cover (54) and the elastic cloth (53) are fixedly connected. The bottom of each set of swing plates (52) and the drain cover (51) are connected by a driving component.

8. The oxygen control device for preparing sintered permanent magnets according to claim 7, characterized in that: The driving component includes an inner guide cylinder (55) fixed to the bottom of the swing plate (52) and an outer guide cylinder (56) fixed to the bottom of the drainage hood (51). Both the inner guide cylinder (55) and the outer guide cylinder (56) are set as arc-shaped cylinders with the hinge axis as the center. The inner guide cylinder (55) is slidably assembled inside the outer guide cylinder (56). A driving airbag is installed between the inner guide cylinder (55) and the outer guide cylinder (56). The driving airbag is connected to the air storage bag (310) through the air guide pipe.

9. A sintered permanent magnet, formed from an oxygen control device based on the sintered permanent magnet according to any one of claims 1-8, characterized in that: The invention includes a permanent magnet substrate, an epoxy film layer is stacked on the surface of the permanent magnet substrate, a conductive resin film layer is stacked on the surface of the epoxy film layer, and an anti-oxidation layer is stacked on the surface of the conductive resin film layer.

10. A method of using an oxygen control device prepared from a sintered permanent magnet, implemented using the oxygen control device prepared from a sintered permanent magnet as described in claim 8, characterized in that: Includes the following steps: S1: The magnetic powder is introduced into the oxygenator (10). First, the magnetic powder accumulates inside the cleaner (20). The airflow ejected by multiple sets of oblique jet nozzles (22) forms a spiral airflow field in the cleaner (20), driving the magnetic powder to form a vortex and quickly stripping the adsorbed oxygen on the surface of the magnetic powder particles. S2: After the magnetic powder cleaning is completed, the magnetic powder particles enter the homogenizer (30). The electrode plate (31) generates uniform plasma to reduce the surface oxides. The dispersion disk (34) rotates so that the magnetic powder particles are evenly distributed in the dispersion disk (34), mechanically breaking up the agglomerates and exposing the fresh surface of the magnetic powder. The gas distribution ring introduces protective gas into the homogenizer (30) so that the protective gas evenly covers the surface of the magnetic powder. S3: After the magnetic powder surface is activated, the magnetic powder is introduced into the gradient oxygen controller (40). Under the action of the guide (50), the magnetic powder is evenly dispersed inside the gradient oxygen controller (40). The different opening ratios of the rhomboid hole oxygen control layer (41), the circular hole oxygen control layer (42), and the strip hole oxygen control layer (43) make oxygen gradients of different orders of magnitude formed from top to bottom inside the gradient oxygen controller (40), thus completing the surface passivation of the magnetic powder, improving the oxidation resistance and magnetic properties of the magnetic powder, and finally discharging it.

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