Power-supply-free static high-intensity magnetic field magnetizing system and passive magnetizing method

Abstract

The system comprises a core magnetizing unit, the core magnetizing unit comprises a permanent magnet array composed of a plurality of high-performance sintered neodymium-iron-boron magnets, and the permanent magnet array adopts a Halbach magnetic circuit design and is used for generating a stable super-strong static space magnetic field in a central area; magnetizing the magnetic material; the automatic feeding system comprises a feeding unit and an independent feeding mechanism, and the feeding unit is used for feeding magnetic materials into the central area; the high-performance permanent magnet array is adopted to construct the static space magnetic field to serve as a magnetizing source, the essential electric energy consumption link in a traditional electromagnetic magnetizing mode is eliminated, zero-energy-consumption operation in the magnetizing process is achieved, and therefore the energy cost for long-term use is reduced, and the energy utilization rate is increased. And the problem of impact on a power grid due to use of large current is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of permanent magnet material magnetizing process, and particularly relates to a static strong magnetic field magnetizing system without power supply and a power-free magnetizing method. BACKGROUND

[0002] The magnetizing process of magnetic materials usually relies on external power excited magnetic field generating devices such as solenoid or electromagnet system. Such devices generate high-intensity pulse magnetic field by passing transient large current in the conductor, so that the magnetic material reaches the magnetization saturation state.

[0003] The solenoid magnetizing mode needs to be matched with a special energy storage and discharge power supply. When the power supply releases the electric energy in a very short time, the inductive reactance of the coil itself will cause the magnetic field to be established in a very short time, and the magnetic field can usually only be maintained for one or two hundred microseconds, and the strong magnetic field cannot be provided for a long time. Moreover, the current release process needs to overcome the inductive reactance, and the electric energy utilization rate is not high, and part of the energy will be consumed in the form of heat. If the heat cannot be taken away in time, the temperature of the solenoid will rise. Temperature change will increase the resistance of the solenoid, and the increased resistance will further reduce the current, and the generated magnetic field will be further reduced. The use of electromagnet to generate a strong magnetic field also has the problem of temperature rise, and needs a super-high current, which has a great impact on the power grid, and the energy utilization rate is even lower.

[0004] Therefore, in view of the above problems, the present application provides a static strong magnetic field magnetizing system without power supply and a power-free magnetizing method. SUMMARY

[0005] In order to overcome the problems of large electric energy consumption, limited magnetic field duration and obvious system temperature rise in the traditional magnetizing mode, the present application provides a static strong magnetic field magnetizing system without power supply and a power-free magnetizing method. The system uses high-performance permanent magnet materials and specific magnetic circuit design to form a continuous and stable strong magnetic field without external power supply, thereby realizing an efficient, energy-saving and simplified magnetizing process.

[0006] The technical scheme of the present application is as follows: a static strong magnetic field magnetizing system without power supply, comprising: a core magnetizing unit, comprising a permanent magnet array composed of a plurality of high-performance sintered neodymium-iron-boron magnets, the permanent magnet array is designed by Halbach magnetic circuit, and is used for generating a stable super-strong static space magnetic field in the central region to magnetize the magnetic material; Wherein, the permanent magnet array comprises at least 8 magnets, each magnet has a different orientation direction, the Halbach magnetic circuit design enhances the magnetic field intensity in the central region and reduces the external magnetic leakage, the high-performance sintered neodymium-iron-boron magnet has a residual magnetization Br≥1.4T, and the magnetic field is a continuous static field without time decay; The automatic feeding system comprises a feeding unit for feeding magnetic materials into a central area and an independent feeding mechanism for ensuring that adjacent magnetic materials are isolated from each other during magnetization to avoid mutual attraction or repulsion and adjusting the magnetization direction of the magnetic materials to be consistent with the magnetic field direction of the central area, wherein the independent feeding mechanism is a separation bin made of non-magnetic material or a mechanical clamp jaw, and the product spacing is greater than 10 mm to avoid magnetic interaction. The core magnetization unit does not require external power supply, the super-strong static space magnetic field exists continuously, has no time limit, and consumes no electric energy.

[0007] Preferably, a magnetic pole convergence component is arranged at the outer magnetic pole of the permanent magnet array, which is composed of a high-permeability material and is used for restraining magnetic lines and reducing the leakage of the assembly to the outside and optimizing the magnetic field uniformity of the central area.

[0008] Preferably, the size of the permanent magnet array can be adjusted to adapt to the demand for static magnetic field of different space sizes, and the overall size of the permanent magnet array is in proportional relationship with the size of the central area, when the size of the central area increases, the overall size of the permanent magnet array is enlarged in proportion, the diameter of the central area is adjustable in the range of 5-50 mm, and correspondingly, the overall size of the permanent magnet array is scaled in proportion in the range of 50-500 mm.

[0009] Preferably, the number of magnets in the permanent magnet array can be increased to 12, 16 or more, wherein as the number of magnets increases, the included angle between the orientation directions of adjacent magnets decreases, and preferably, when the number of magnets increases to 16, the orientation angle difference between adjacent magnets is 22.5 degrees, wherein the increase in the number of magnets can improve the magnetic field uniformity, but also increase the volume and weight of the system.

[0010] Preferably, the ratio of the size of the central area to the overall size of the permanent magnet array can be adjusted to adjust the magnetic field strength of the central static magnetic field, when the overall size is unchanged, the increase in the size of the central area reduces the central static magnetic field strength, and the decrease in the size of the central area increases the central static magnetic field strength, and the ratio D / L of the size (diameter D) of the central area to the overall size (diameter L) is adjustable between 0.05 and 0.3, so as to realize the control of the central magnetic field strength in the range of 2.0T to 3.0T.

[0011] The application provides a passive magnetization method of a power-free static strong magnetic field magnetization system, comprising the following steps: S1, generating a super-strong static magnetic field in the central area by using a permanent magnet array; S2, the magnetic material is sent into the central area by an automatic feeding system, wherein an independent feeding mechanism ensures that adjacent magnetic materials are isolated from each other to avoid mutual interference, and the feeding speed is 10-60 pieces per minute, depending on the product size and the time required for saturation magnetization; S3, the rotation angle of the feeding mechanism is controlled by PLC to make the easy magnetization direction of the magnetic material consistent with the magnetic field direction of the central area; S4, after the magnetization is completed, an external force is applied to the magnetic material by a pneumatic or electric push rod, and a mechanical device provides a separation energy, so that the magnetic material is separated from the central area, and the required separation force F needs to meet: Wherein μ is the magnetic permeability, B is the central magnetic field strength, A is the product cross-sectional area, is the vacuum permeability.

[0012] As a preferred, the feeding unit of the automatic feeding system comprises a sensor and a control system for real-time monitoring and adjusting the position and direction of the magnetic material.

[0013] As a preferred, the magnetic field strength of the permanent magnet array is optimized by adjusting the number, size of the magnet or the proportion of the central area to the overall shape to adapt to the magnetization requirements of different magnetic materials.

[0014] The beneficial effects of the present application are: 1. The present application adopts a high-performance permanent magnet array to construct a static space magnetic field as a magnetization source, eliminating the necessary power consumption link in the traditional electromagnetic magnetization method, realizing zero-energy consumption operation in the magnetization process, thereby reducing the long-term energy cost, and avoiding the impact on the power grid caused by using large current.

[0015] 2. Since the magnetic field generated by the permanent magnet is a static field that exists inherently and continuously, the strong magnetic field provided by the present application can be maintained stably for a long time, thereby solving the problem caused by the extremely short duration (usually only a few hundred microseconds) of the pulse magnetic field of the solenoid, and ensuring that high-coercivity magnetic materials can also be fully and reliably saturated and magnetized.

[0016] 3. In the working process of the magnetization system constructed by the present application, the core permanent magnet array will not generate Joule heat due to power-on, thereby eliminating the serious temperature rise problem caused by the coil resistance in the traditional electromagnetic magnetization device. This not only simplifies the system structure (without the need for a complex cooling system), but also avoids the magnetic field attenuation and equipment life reduction caused by temperature rise, thereby improving the reliability and stability of the system. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The construction principle of the present application is shown in the schematic diagram; Figure 2A workflow schematic of the embodiment 1 of the present application is shown. Figure 3 A workflow schematic of the embodiment 2 of the present application is shown.

[0018] Reference signs: 1, magnetic pole convergence component; 2, magnet one; 3, magnet two; 4, magnet three; 5, magnet four; 6, magnet five. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0020] The present application provides an embodiment, a static strong magnetic field power-free magnetizing system: In the embodiment, the core magnetizing unit is described, including a permanent magnet array and a magnetic pole convergence component, specifically: The permanent magnet array adopts a sintered neodymium iron boron (NdFeB) material with the highest performance grade, and the magnetic performance parameters are as follows: residual magnetism Br≥1.45T, intrinsic coercive force Hcj≥1990kA / m, and maximum magnetic energy product (BH)max≥52MGOe.

[0021] The Halbach array principle is adopted for construction. The basic form of the array is a ring-shaped structure composed of a plurality of (at least 8) magnet blocks with a sector or trapezoidal cross section surrounding a central cavity (i.e. a magnetizing area), and the magnetization direction of each magnet block is continuously deflected according to a certain rule. For example, in an 8-unit Halbach array, the magnetization direction of adjacent magnet blocks forms an angle of 45 degrees. This special arrangement can maximize the concentration of magnetic field energy in the central area on the inner side of the array, while significantly weakening the magnetic field (leakage) on the outer side of the array, thereby maximizing the central magnetic field strength without the need for an iron yoke or only a small amount of magnetic pole convergence components.

[0022] Through this design, an 8-unit Halbach array with an outer diameter of 200mm can generate a stable and uniform static magnetic field in the central area (diameter about 20mm), and the strength can reach 3T through finite element software simulation calculation, and the magnetic field direction is perpendicular to the axis of the central cavity, which is suitable for magnetizing magnetic rings or specific orientation magnetic blocks in the radial direction.

[0023] The pole convergence component is made of soft magnetic material with high saturation magnetic induction, such as industrial pure iron or permalloy, which is precisely processed into arc-shaped pole heads and installed at the inner side of the magnetic poles of the permanent magnet array or placed at specific positions of the array according to the magnetic field distribution requirements.

[0024] The pole convergence component functions like a "magnetic lens" to perform secondary constraint and focusing on the preliminary converged magnetic lines of the Halbach array, thereby obtaining a higher peak magnetic field strength at the center point of the magnetizing area than the simple Halbach array.

[0025] In this embodiment, the automatic feeding system is described, including a feeding unit and an independent feeding mechanism, specifically: The feeding unit includes a vibrating disc or a linear feeder for arranging bulk products in order and outputting them one by one, followed by a conveyor belt or a linear module driven by a servo motor, which is responsible for conveying the products to the center area of the core magnetizing unit.

[0026] The independent feeding mechanism includes an isolation bin made of non-magnetic material or a mechanical gripper, which is located at the end of the conveyor belt and is responsible for grabbing or carrying a single product at the magnetizing station.

[0027] The isolation bin keeps a sufficient physical distance (usually > 15mm) between the adjacent two products during the magnetizing process, effectively avoiding the mutual attraction or repulsion caused by the product's own magnetization or magnetization in a high magnetic field environment, ensuring smooth feeding and positioning accuracy.

[0028] The mechanism is integrated with a rotating shaft driven by a micro servo motor, which can hold the product and rotate around its axis through a pre-set program or feedback from a visual sensor (such as a CCD camera), accurately adjusting the "magnetizable direction" of the product to keep it consistent with the direction of the central static magnetic field of the core magnetizing unit, with a positioning accuracy controlled within ±0.3 degrees.

[0029] After magnetizing is completed, the highly magnetized product will have a strong adsorption force with the pole convergence component or the surrounding magnetic field, and the mechanism needs to exert a large enough mechanical force (achieved through a pneumatic push rod or an electric cylinder) to "pull" or "push" the product away from the magnetizing area.

[0030] Please refer to Figure 1, magnetic pole convergence component 1, with different orientation direction magnet 2, magnet 3 and magnet 5, magnet 5, together constitute a Halbach array, the magnetic force line of the whole subassembly is restricted in the magnetic assembly, and a closed loop is formed with magnet 4, solve the whole construction to the external magnetic problem; Each magnet adopts high-performance sintered neodymium iron boron material, the magnetic force is strong, and the whole magnetic assembly is small to the external leakage magnetic, all the magnetic force line is internal closed, so it can form a static space magnetic field of about 3T in the center area of the magnetic assembly, it can meet the magnetization of the magnetic material smaller than the center aperture.

[0031] The present application provides example 1: Please refer to Figure 2 , this embodiment is used to produce neodymium iron boron radial magnetic ring with outer diameter of 10mm, inner diameter of 6mm and height of 5mm, and the magnetization direction needs to be completed along the radial direction.

[0032] The core magnetizing unit of this embodiment adopts 8-unit Halbach array structure, and the magnet material selects high-performance sintered neodymium iron boron, the array outer diameter is 120mm, the inner diameter is 25mm, and the inner side is lined with industrial pure iron magnetic pole convergence component, the assembly can further converge the effective magnetization area to 15mm in diameter, and through finite element simulation verification, in this state, the center area can generate a stable static magnetic field of up to 2.0T.

[0033] Its automatic feeding system is responsible for sorting bulk magnetic rings by vibration disc and transmitting to the work station through linear module, the key component independent feeding mechanism adopts two-finger pneumatic clamps made of austenitic stainless steel, the end of the clamp is embedded with V-shaped block controlled by servo motor to adapt to the shape of the magnetic ring and realize rotary alignment, after magnetization, the mechanical force provided by the linear module backward movement of the clamp is relied on to overcome the strong magnetic adsorption, so as to realize the separation of the product.

[0034] Work flow: after the magnetic ring is sorted by the vibration disc, it is conveyed to the magnetizing work station through the linear module, then the magnetic ring is grabbed by the pneumatic clamp and rotated by the servo motor to make the radial easy magnetization direction and the center static magnetic field direction accurately aligned, then the magnetic ring is sent into the center of the magnetic field and kept for 0.5 seconds to complete the full magnetization, finally the clamp drives the magnetic ring to retreat quickly from the strong magnetic field area and releases it to the finished product collection area, the whole process does not need external power supply, the surface magnetic field strength of the product after magnetization can reach more than 800mT and is uniformly distributed, saturation magnetization is realized, and the production efficiency is stable at 40 pieces per minute.

[0035] The present application provides example 2: Please refer to Figure 3 , this embodiment is used to produce sintered ferrite square magnet with outer diameter of 20mm, inner diameter of 10mm and height of 5mm, and the magnetization direction needs to be magnetized along the length direction.

[0036] The core magnetizing unit of the embodiment adopts a 16-unit Halbach array structure, the magnet material is selected to be high-performance sintered neodymium iron boron, the outer diameter of the array is 300 mm, the inner diameter, i.e., the magnetizing area, is 60 mm, and a permalloy magnetic pole convergence component is lined on the inner side, the assembly further converges the effective magnetizing area to a diameter of 12 mm, and it is verified by finite element simulation that a stable static magnetic field of up to 1.6 T can be generated in the central area in this state.

[0037] The automatic feeding system thereof is responsible for feeding by a belt conveying line, the independent feeding mechanism is a jacking rotary platform with an isolation bin, when the product is sent into the isolation bin by the belt, the bin body is first jacked to be physically isolated from the main conveying line, then the platform is rotated by 90° to ensure that the long side of the product is completely parallel to the magnetic field direction, after the magnetization is completed, the pneumatic ejector rod installed at the bottom is used to apply an upward separation force, the magnetized product is reliably ejected from the isolation bin and sent back to the conveying belt.

[0038] The working process is as follows: the belt conveying line continuously sends the square block magnets into the isolation bin, then the jacking mechanism is triggered to make the isolation bin with the product rise after being positioned by the photoelectric sensor, then the rotary platform moves to complete the product orientation and accurately drop the product into the preset position between the magnetizing pole heads, after keeping magnetizing for 1 second, the pneumatic ejector rod quickly moves to separate the product from the strong magnetic field area and drop it back to the conveying belt to the finished product area.

[0039] The present application provides Comparative Example 1: The present comparative example sets a simulation experiment taking the Φ10 mm radial magnetic ring in Example 1 as the experimental object, wherein the experimental group is Example 1, Comparative Example 1 is a traditional capacitor discharge pulse magnetizing system, a 10000 μF capacitor is used to discharge through a multi-turn air-core solenoid at a voltage of 400 V, and Comparative Example 2 is a steady-state electromagnet system, a water-cooled electromagnet is used, and a high-power DC power supply is used for power supply.

[0040] The present comparative example verifies by detecting the surface magnetic field strength after magnetization, single magnetization energy consumption, magnetic field duration, system temperature rise and magnetization uniformity.

[0041] From the above table, it can be seen that the single energy consumption of Comparative Example 1 is not high, but the cumulative power consumption in batch production is considerable, the energy consumption of Comparative Example 2 is extremely high, and the operation cost is huge, and the present application fundamentally solves the problem of high power consumption.

[0042] The pulse magnetic field duration of Comparative Example 1 is extremely short (microsecond level), and for high-coercivity materials, it may not be able to make the magnetic domain complete flip, resulting in incomplete magnetization, the present application ensures that the material has sufficient time to reach magnetization saturation, which is the key reason why the magnetization uniformity (standard deviation 8.5 mT) of the experimental group is much better than that of Comparative Example 1 (25.3 mT), although Comparative Example 2 can be sustained, it is at the cost of huge energy consumption and temperature rise.

[0043] The core components of the experimental group have almost no temperature rise, and the temperature rise of Comparative Example 1 and Comparative Example 2 is obvious. The temperature rise will cause the coil resistance to increase (the magnetic field of Comparative Example 1 is weakened), the performance of the magnetic pole may be degraded (Comparative Example 2), and an additional cooling system is needed, which increases the complexity and failure points.

[0044] The above is only a preferred embodiment of the present application, and is not intended to limit the present application in other forms. Any skilled person in the art can use the disclosed technology to make changes or modifications to equivalent embodiments that are equivalent to the changes, and apply them to other fields. However, any simple modification, equivalent change and modification made to the above embodiments in accordance with the technical essence of the present application without departing from the technical solution content of the present application still falls within the protection scope of the technical solution of the present application.

Claims

1. A power-free static high magnetic field magnetizing system, characterized in that, The application relates to a core magnetizing unit, which comprises a permanent magnet array composed of multiple high-performance sintered Nd-Fe-B magnets, and the permanent magnet array adopts a Halbach magnetic circuit design to generate a stable super-strong static space magnetic field in a central region for magnetizing magnetic materials. The permanent magnet array comprises at least eight magnets, each of which has a different orientation direction, and the Halbach magnetic circuit design enhances the magnetic field intensity in the central region and reduces external magnetic leakage. The automatic feeding system comprises a feeding unit for feeding the magnetic materials into the central region and an independent feeding mechanism for ensuring that adjacent magnetic materials are isolated from each other during the magnetizing process to avoid mutual attraction or repulsion and adjusting the easy magnetization direction of the magnetic materials to be consistent with the magnetic field direction of the central region. The core magnetizing unit does not need external power supply, the super-strong static space magnetic field exists continuously without time limit, and no electric energy is consumed. The external magnetic pole of the permanent magnet array is provided with a magnetic pole convergence component composed of a high-permeability material for restraining magnetic lines and reducing external magnetic leakage of the assembly.

2. A power-free static strong magnetic field magnetizing system according to claim 1, characterized in that: The size of the permanent magnet array can be adjusted to adapt to the demand of the static magnetic field of different space sizes.

3. A power-free static strong magnetic field magnetizing system according to claim 1, characterized in that: The overall size of the permanent magnet array is in proportional relationship with the size of the central region, and when the demand central size is increased, the overall size of the permanent magnet array is enlarged in proportion.

4. A power-free static strong magnetic field magnetizing system according to claim 3, characterized in that: The number of magnets of the permanent magnet array can be increased to 12, 16 or more, wherein with the increase of the number of magnets, the included angle of the orientation direction of adjacent magnets is reduced.

5. A power-free static strong magnetic field magnetizing system according to claim 1, characterized in that: The ratio of the central region size to the overall size of the permanent magnet array can be adjusted to adjust the magnetic field intensity of the central static magnetic field, and when the overall size is unchanged, the central static magnetic field intensity is reduced when the central region size is increased, and the central static magnetic field intensity is increased when the central region size is reduced.

6. A power-free static strong magnetic field magnetizing system according to claim 1, characterized in that: The application further discloses a core magnetizing method, which comprises the following steps:

7. A passive magnetizing method of a power-free static strong magnetic field magnetizing system, according to any one of claims 1-6, wherein, S1, generating a super-strong static magnetic field in the central region by using the permanent magnet array; S2, feeding the magnetic materials into the central region by the automatic feeding system, wherein the independent feeding mechanism ensures that adjacent magnetic materials are isolated from each other to avoid mutual interference; S3, adjusting the easy magnetization direction of the magnetic materials to be consistent with the magnetic field direction of the central region; S4, after the magnetizing is completed, an external force is applied to the magnetic materials, a mechanical device provides a separation energy to make the magnetic materials separate from the central region. The feeding unit of the automatic feeding system comprises a sensor and a control system for monitoring and adjusting the position and direction of the magnetic materials in real time.

8. The passive magnetizing method of a power-free static strong magnetic field magnetizing system according to claim 7, characterized in that: In the step S4, the external force is provided by a pneumatic or electric push rod.

9. The passive magnetizing method of a power-free static strong magnetic field magnetizing system according to claim 7, characterized in that: The magnetic field intensity of the permanent magnet array is optimized by adjusting the number, size or ratio of the central region to the overall size of the magnets to adapt to the magnetizing requirements of different magnetic materials.

10. The passive magnetizing method of a power-free static strong magnetic field magnetizing system according to claim 7, characterized in that: ​

Images