Radial magnetic ring material, preparation mold of multi-pole magnetic ring and preparation method thereof

Abstract

The application discloses a kind of radial magnetic ring materials and preparation method of multipolar magnetic ring, comprising the following steps: using wet grinding method to permanent magnet ferrite magnetic powder is finely ground twice to obtain slurry;Slurry is filtered to remove water, so that the moisture content of slurry is between 30% and 33%;Through die, pre-magnetization is carried out to green compact, so that the density of green compact is 2.8-3.2g / cm 3 , the height of green compact is 15-25mm;Water is pumped out to disordered slurry, and the orientation direction of magnetic domain is fixed, and the green compact in the mold is demagnetized by the reverse magnetic field;The application further discloses a kind of radial magnetic ring materials and preparation method of multipolar magnetic ring used to preparation mold.The application solves the problem of multipolar orientation of multipolar green compact, and the high performance of product is ensured by the orientation of granular material, and the good flow performance of granular material ensures the completion of automatic scraping process, and ensures the weight consistency of different times of green compact.

Description

Technical Field

[0001] This invention belongs to the field of permanent magnet ferrite production technology, specifically relating to a radial magnetic ring material and a preparation mold for multi-pole magnetic rings and their preparation method. Background Technology

[0002] With the improvement of people's living standards, household appliances and high-tech electronic products have developed rapidly in recent years. Magnetism and electricity are integrated; currently, wherever there is electricity, magnets are indispensable. Examples include washing machines, air conditioners, miniature fans, home cooking appliances, microwave ovens, robots, monitoring equipment, and automated control systems. For some motors with lower requirements, a homogeneous molding process can be used, resulting in multi-pole magnetization of the finished product. However, for motors with higher performance requirements, wet-process anisotropic molding blanks are mostly used to create magnetic tiles or blocks, which are then assembled into magnetic poles.

[0003] The former has a simple manufacturing process but often has low performance and relatively low motor torque; while the latter has a relatively large overall size. However, for products such as household micro water pumps and mahjong machine motors on the market, it is clear that the aforementioned two types cannot meet their requirements. Therefore, radial multi-pole oriented magnetic ring motors, which have both a small size and relatively good performance, have emerged, perfectly balancing the advantages and avoiding the disadvantages.

[0004] However, due to defects in mold design and the internal problems of granules, the production of multi-polar radial products is difficult. As a result, the granules have difficulty entering the mold cavity smoothly during the blanking process. Moreover, the cracking rate of multi-polar oriented blanks is particularly high after sintering. Summary of the Invention

[0005] The purpose of this invention is to provide a radial magnetic ring material and a method for preparing multipole magnetic rings, thereby solving the problems mentioned in the background art. The radial magnetic ring material and method for preparing multipole magnetic rings provided by this invention have the advantages of reducing raw material loss, improving production efficiency, and enhancing product quality.

[0006] Another objective of this invention is to provide a preparation mold used in the preparation of radial magnetic ring materials and multipole magnetic rings.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a radial magnetic ring material and a method for preparing a multi-pole magnetic ring, comprising the following steps:

[0008] (i) The permanent magnet ferrite powder is finely ground twice by wet grinding to obtain a slurry;

[0009] (ii) Filter the slurry to remove water, so that the water content of the slurry is between 30% and 33%;

[0010] (III) Pre-magnetize the blank using a mold to achieve a density of 2.8-3.2 g / cm³.3 The height of the blank is 15-25mm;

[0011] (iv) Pump out the disordered slurry, fix the orientation of the magnetic domains, and demagnetize the blank in the mold by using a reverse magnetic field.

[0012] (v) The blank is crushed to obtain fine powder, and then granulated by adding binder and lubricant;

[0013] (vi) Add the granulated granules into the preparation mold for pressing and magnetizing;

[0014] (vii) Place it in a sintering equipment for sintering.

[0015] In order to improve the loose density and flowability of the granules and reduce the proportion of fine powder, further, in step (iv), the demagnetization treatment temperature is 200-450℃ and the demagnetization treatment time is 1-2h.

[0016] In order to make the granules have a high loose density and be able to enter the mold cavity smoothly and evenly, thereby improving production efficiency, further, in step (5), 0.2%-1.2% of binder and 0.3%-0.8% of lubricant are added.

[0017] To ensure that the granules have sufficient time and magnetic field to arrange them in an orderly manner before being pressed into blanks, in step (vi), magnetization is performed by an intermittent capacitor pulse magnetization system with a capacitance of ≥10000uF and a single discharge time interval of 0.01s-0.05s.

[0018] In order to ensure that the magnetization system can have at least three electromagnetization effects during the granule pressing process and achieve complete orientation, in step (vi), a hydraulic press is used with the upper cylinder pressing speed of 4-6 m / s.

[0019] In order to achieve a surface magnetic energy of 206.8 mT for the quadrupole magnetic ring, which improves the performance by 74.46%, the sintering temperature in step (vii) is 1250℃-1280℃.

[0020] To solve the organic transition between magnetic poles, completely resolve the cracking problem between adjacent poles after sintering of multi-pole oriented magnetic steel, and reduce the grinding workload of the product and improve material utilization, the preparation mold used in the radial magnetic ring material and multi-pole magnetic ring preparation method of the present invention includes a magnetic conductor, an alloy concave mold inside the magnetic conductor, multiple pole blocks arranged in a ring on the inner wall of the magnetic conductor, copper coils wound on the pole blocks, a pole arc at the end of the pole block, the pole arc abutting against the outer wall of the alloy concave mold, a first concave arc corresponding to the pole arc on the inner wall of the alloy concave mold, and a second concave arc on each side of the first concave arc.

[0021] Furthermore, both ends of the polar arc are rounded.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. This invention solves the problem of multi-orientation in multi-stage blank pressing. The granules are fixed in orientation to ensure the high performance of the product. The good flowability of the granules ensures the completion of the automatic scraping process and ensures the consistent weight of blanks pressed in different stages.

[0024] 2. This invention gives the granules a high bulk density, generally greater than 1.5 g / cm³. 3 The fluidity has also been greatly improved, with an angle of repose of no more than 31 degrees, allowing it to enter the mold cavity smoothly and evenly, thus improving production efficiency.

[0025] 3. Because the granular material has a higher loose density, the present invention has a smaller filling ratio, which can reduce the cavity of the concave mold, save mold costs, and improve the performance by nearly 17% under the same conditions of other processes.

[0026] 4. This invention uses an intermittent capacitive pulse magnetization system for magnetization, with a capacitance of ≥10000uF and a single discharge time interval of 0.01s-0.05s, ensuring that the granules have sufficient time and magnetic field to arrange them in an orderly manner before being pressed into blanks;

[0027] 5. This invention uses a hydraulic press with an upper cylinder pressing speed of 4-6 m / s to ensure that the magnetization system has at least three electromagnetization effects during the granular material pressing process, thus achieving complete orientation.

[0028] 6. This invention solves the problem of organic transition between magnetic poles, completely solves the problem of cracking between adjacent poles after sintering of multi-pole oriented magnets, and can reduce the amount of grinding work on the product and improve the utilization rate of materials. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the present invention;

[0030] Figure 2 For the present invention Figure 1 Enlarged structural diagram at point A;

[0031] In the diagram: 1. Magnetic conductor; 2. Pole block; 3. Pole arc; 31. Rounded corner; 4. Copper coil; 5. Alloy concave mold; 6. First concave arc; 7. Second concave arc. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Example 1

[0034] Please see Figure 1-2 The present invention provides the following technical solution: a radial magnetic ring material and a method for preparing a multipole magnetic ring, comprising the following steps:

[0035] (i) The permanent magnet ferrite powder is finely ground twice by wet grinding to obtain a slurry;

[0036] (ii) Filter the slurry to remove water, so that the water content of the slurry is between 30% and 33%;

[0037] (III) Pre-magnetize the blank using a mold to achieve a density of 2.8-3.2 g / cm³. 3 The height of the blank is 15-25mm;

[0038] (iv) Pump out the disordered slurry, fix the orientation of the magnetic domains, and demagnetize the blank in the mold by using a reverse magnetic field.

[0039] (v) The blank is crushed to obtain fine powder, and then granulated by adding binder and lubricant;

[0040] (vi) Add the granulated granules into the preparation mold for pressing and magnetizing;

[0041] (vii) Place it in a sintering equipment for sintering.

[0042] By adopting the above technical solution, the multi-orientation problem of multi-stage blank pressing is solved. The granular material is fixed in orientation to ensure the high performance of the product. The good flowability of the granular material ensures the completion of the automatic scraping process and ensures the consistent weight of blanks pressed in different stages.

[0043] Specifically, in step (four), the demagnetization treatment temperature is 200-450℃, and the demagnetization treatment time is 1-2 hours.

[0044] By adopting the above technical solutions, the loose density and flowability of granular materials are improved, while the proportion of fine powder is reduced.

[0045] Specifically, in step (5), add 0.2%-1.2% adhesive and 0.3%-0.8% lubricant.

[0046] By adopting the above technical solution, the granular material can have a high bulk density, generally greater than 1.5 g / cm³. 3 The fluidity is also greatly improved, with an angle of repose of no more than 31 degrees, which allows it to enter the mold cavity smoothly and evenly, thus improving production efficiency. At the same time, due to the higher loose density of the granular material, it has a smaller filling ratio, which can reduce the number of concave mold cavities, save mold costs, and improve performance by nearly 17% compared with other processes under the same conditions.

[0047] Specifically, in step (six), magnetization is performed using an intermittent capacitive pulse magnetization system with a capacitance of ≥10000uF and a single discharge time interval of 0.01s-0.05s.

[0048] By adopting the above technical solution, it is ensured that the granular material has sufficient time and magnetic field to arrange itself in an orderly manner before being pressed into blanks.

[0049] Specifically, in step (six), a hydraulic press is used, with the upper cylinder pressing at a speed of 4-6 m / s.

[0050] By adopting the above technical solution, it is ensured that the magnetization system can have at least three electromagnetic discharge effects during the granule pressing process (before forming a high-strength blank), so as to achieve the purpose of complete orientation.

[0051] Specifically, in step (vii), the sintering temperature is 1250℃-1280℃.

[0052] By adopting the above technical solution, the magnetic energy of the quadrupole magnetic ring can reach 206.8mT, and the performance is improved by 74.46%.

[0053] Example 2

[0054] Furthermore, the preparation mold used in the radial magnetic ring material and the preparation method of the multi-pole magnetic ring described in this invention includes a magnetic conductor 1, an alloy concave mold 5 inside the magnetic conductor 1, four pole blocks 2 arranged in a ring on the inner wall of the magnetic conductor 1, copper coils 4 wound on the pole blocks 2, a pole arc 3 at the end of the pole block 2, the pole arc 3 abutting against the outer wall of the alloy concave mold 5, a first concave arc 6 corresponding to the pole arc 3 on the inner wall of the alloy concave mold 5, a second concave arc 7 on both sides of the first concave arc 6, and rounded corners 31 at both ends of the pole arc 3.

[0055] By adopting the above technical solution, the organic transition between magnetic poles is solved, the cracking problem between adjacent poles after sintering of multi-pole oriented magnets is completely solved, and the grinding amount of the product can be reduced, thereby improving the utilization rate of materials.

[0056] In summary, this invention solves the multi-orientation problem in multi-stage blank pressing. The fixed orientation of the granules ensures high product performance, while the good flowability of the granules ensures the completion of the automatic scraping process and guarantees consistent weight of blanks pressed in different stages. This invention also gives the granules a high bulk density, generally greater than 1.5 g / cm³. 3 The fluidity is also significantly improved, with a repose angle of no more than 31 degrees, allowing for smooth and uniform entry into the mold cavity, thus improving production efficiency. Due to the higher loose density of the granules, this invention has a smaller filling ratio, reducing the number of concave mold cavities, saving mold costs, and improving performance by nearly 17% compared to other processes under the same conditions. This invention uses an intermittent capacitor pulse magnetization system with a capacitance greater than or equal to 10000uF and a single discharge interval of 0.01s-0.05s, ensuring that the granules have sufficient time and magnetic field to arrange themselves in an orderly manner before being pressed into blanks. This invention uses a hydraulic press with an upper cylinder pressing speed of 4-6m / s to ensure that the magnetization system has at least three electromagnetization effects during the granule pressing process, achieving complete orientation. This invention solves the problem of organic transition between magnetic poles, completely resolving the cracking problem between adjacent poles after sintering of multi-pole oriented magnets, and can reduce the amount of grinding work on the product, improving material utilization.

[0057] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A radial magnetic ring material and a method for preparing a multipole magnetic ring, characterized in that: Includes the following steps: (i) The permanent magnet ferrite powder is finely ground twice using a wet grinding method to obtain a slurry; (ii) Filter the slurry to remove water, so that the water content of the slurry is between 30% and 33%; (iii) Pre-magnetize the blank using a mold to make the density of the blank 2.8-3.2 g / cm³ and the height of the blank 15-25 mm; (iv) Pump out the disordered slurry, fix the orientation of the magnetic domains, and demagnetize the blank in the mold by using a reverse magnetic field; (v) The blank is crushed to obtain fine powder, and then granulated by adding binder and lubricant; (vi) Add the granulated granules into the preparation mold, and perform compaction and magnetization; (vii) Place it in a sintering apparatus for sintering; In step (four), the demagnetization treatment temperature is 200-450℃, and the demagnetization treatment time is 1-2 hours; In step (six), magnetization is performed using an intermittent capacitive pulse magnetization system with a capacitance of ≥10000uF and a single discharge time interval of 0.01s-0.05s. In step (six), a hydraulic press is used, with the upper cylinder pressing at a speed of 4-6 m / s. The preparation mold used in the above method includes a magnetic conductor, an alloy concave mold inside the magnetic conductor, multiple pole blocks arranged in a ring on the inner wall of the magnetic conductor, copper coils wound on the pole blocks, pole arcs at the ends of the pole blocks, the pole arcs abutting against the outer wall of the alloy concave mold, a first concave arc corresponding to the pole arc on the inner wall of the alloy concave mold, and a second concave arc on each side of the first concave arc; both ends of the pole arcs are rounded. The loose density of the granular material is greater than 1.5 g / cm³, and the angle of repose is not greater than 31 degrees.

2. The radial magnetic ring material and the method for preparing a multipole magnetic ring according to claim 1, characterized in that: In step (5), add 0.2%-1.2% adhesive and 0.3%-0.8% lubricant.

3. The radial magnetic ring material and the method for preparing a multipole magnetic ring according to claim 1, characterized in that: In step (vii), the sintering temperature is 1250℃-1280℃.

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