Magnet, manufacturing method thereof and predetermined orientation magnetic field mold

Abstract

The invention provides a magnet, a manufacturing method thereof and a predetermined orientation magnetic field mold. The embodiment of the invention provides a method for manufacturing a magnet, and the method comprises the steps: carrying out the injection molding of a prefabricated magnet based on a magnet raw material in a preset orientation magnetic field environment, and enabling the magnet raw material to comprise an isotropic magnetic material and a binder; and demagnetizing the prefabricated magnet. According to the method for manufacturing the magnet provided by the embodiment of the invention, the content of the isotropic magnetic material at the acting pole of the prefabricated magnet is increased and the content of the isotropic magnetic material at the non-acting pole of the prefabricated magnet is reduced by arranging the prefabricated magnet formed by injection molding in the magnetic field environment with the preset orientation; therefore, the magnetic performance of the finally obtained magnet is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of magnetic material forming, and particularly to a magnet, a manufacturing method thereof, and a predetermined orientation magnetic field mold. Background Art

[0002] Magnetic materials have important applications in many fields. For example, in the thermal management fields such as automobiles and household appliances, high-performance cooling water pumps are required in the cooling systems. The cooling water pump includes a magnetic rotor, and the magnetic ring of the magnetic rotor is a key heat-dissipating part.

[0003] In the current market, the magnetic rings of magnetic rotors are commonly made by sintered neodymium iron boron and injection-molded neodymium iron boron. However, sintered neodymium iron boron has problems such as heavy weight and large dynamic balance, and injection-molded neodymium iron boron magnetic rings are more preferred in the market. The injection-molded neodymium iron boron magnetic ring is a magnetic ring formed by melting and injection molding after mixing neodymium iron boron magnetic powder and an adhesive. Magnetic materials mainly include isotropic and anisotropic materials. Currently, almost all the injection-molded neodymium iron boron magnetic rings on the market are injection-molded with isotropic materials to ensure the characteristics of the magnetic ring; then the magnetic ring is magnetized after being assembled into the water pump rotor.

[0004] However, the magnetic performance of the magnetic ring needs to be improved. Summary of the Invention

[0005] In view of this, it is necessary to provide a magnet, a manufacturing method thereof, and a predetermined orientation magnetic field mold for the above problems.

[0006] An embodiment of the present disclosure provides a method for manufacturing a magnet, including: injecting and molding a preformed magnet based on magnet raw materials in a predetermined orientation magnetic field environment, wherein the magnet raw materials include isotropic magnetic materials and a binder; and demagnetizing the preformed magnet.

[0007] The method for manufacturing a magnet provided by the embodiment of the present disclosure increases the content of isotropic magnetic materials at the acting poles of the preformed magnet and reduces the content of isotropic magnetic materials at the non-acting poles of the preformed magnet by injecting and molding in a predetermined orientation magnetic field environment, thereby improving the magnetic performance of the finally obtained magnet.

[0008] In some embodiments, the method further includes: positioning and magnetizing the preformed magnet that has undergone the demagnetization step.

[0009] With such a setting, compared with the magnet that is usually injection-molded and demagnetized, the surface magnetism and magnetic area of the preformed magnet that is injection-molded in a predetermined orientation magnetic field environment and demagnetized are greatly improved after positioning and magnetizing.

[0010] In some embodiments, the isotropic magnetic material includes neodymium iron boron material, and the binder includes polyphenylene sulfide.

[0011] With such a setting, the isotropic neodymium iron boron material in the magnet raw material can be arranged and distributed according to the design of the predetermined orientation magnetic field during the injection molding process, improving the utilization rate of the isotropic magnetic material and being beneficial to the improvement of the performance of the prefabricated magnet; and the formed distribution state can be maintained by using the binder.

[0012] In some embodiments, the maximum magnetic energy product of the neodymium iron boron material ranges from 3.5 MGOe to 7 MGOe.

[0013] With such a setting, the cost of the magnet formed by using this neodymium iron boron material is controllable, and it can meet the high magnetic requirements of the magnet with a low-performance neodymium iron boron material or can achieve a higher-performance magnet with a neodymium iron boron material of the same performance level. The neodymium iron boron material is cheaper, which is beneficial to reducing costs and improving the competitive advantage.

[0014] In some embodiments, the method further includes: filling the cavity of the predetermined orientation magnetic field mold with the magnet raw material.

[0015] Among them, the predetermined orientation magnetic field mold is used to provide a predetermined orientation magnetic field. The predetermined orientation magnetic field has at least two magnetic poles pointing to the cavity at a predetermined position, and at least two magnetic poles include a south pole and a north pole.

[0016] With such a setting, at least two magnetic poles including a south pole and a north pole are beneficial to form a predetermined orientation magnetic field, and can make the magnet raw material in the cavity form a prefabricated magnet that meets a sine wave.

[0017] In some embodiments, the predetermined orientation magnetic field mold includes a mold sleeve and a plurality of magnetic ring segments, and the mold sleeve is used to define the cavity.

[0018] The method further includes: arranging a plurality of magnetic ring segments around the outer periphery of the mold sleeve and setting the magnetic pole directions of each magnetic ring segment to set the predetermined orientation magnetic field.

[0019] With such a setting, the magnetic pole directions of each magnetic ring segment are used to set the predetermined orientation magnetic field, and a plurality of magnetic ring segments are arranged around the outer periphery of the mold sleeve, so that the magnet raw material in the cavity is injection molded into a prefabricated magnet according to requirements. It is beneficial to improve the utilization rate of the isotropic magnetic material and improve the performance of the prefabricated magnet.

[0020] In some embodiments, the predetermined orientation magnetic field mold is configured to have six magnetic poles to form a magnet with six acting poles.

[0021] With such a setting, the six magnetic poles can better form a predetermined orientation magnetic field environment. By increasing the content of the magnetic material at the acting poles, the performance of the prefabricated magnet is improved. The formed magnet has good circumferential performance.

[0022] Embodiments of the present disclosure provide a predetermined orientation magnetic field mold, which includes a mold sleeve and a plurality of magnetic ring segments. The mold sleeve is used to define a cavity. The plurality of magnetic ring segments are arranged in a circumferential manner around the outer periphery of the mold sleeve, and the plurality of magnetic ring segments are used to form a predetermined orientation magnetic field, and the predetermined orientation magnetic field has at least two magnetic poles pointing to the cavity at a predetermined position, and the at least two magnetic poles include a south pole and a north pole.

[0023] The predetermined orientation magnetic field mold provided by the embodiments of the present disclosure designs a predetermined orientation magnetic field and can be used to manufacture magnets. The content of the isotropic magnetic material at the acting pole of the prefabricated magnet formed by using this predetermined orientation magnetic field mold increases, and the content of the isotropic magnetic material at the non-acting pole decreases. The performance and competitiveness of the prefabricated magnet are improved.

[0024] Embodiments of the present disclosure provide a magnet, which is obtained by the steps of the method for manufacturing a magnet described above, or the magnet is obtained by injection molding using the above-mentioned predetermined orientation magnetic field mold.

[0025] The magnet provided by the embodiments of the present disclosure is formed using an isotropic magnetic raw material in a predetermined orientation magnetic field environment, and the isotropic magnetic materials therein are unevenly distributed, and the content of the magnetic material is higher near the structure at the preset position. The surface magnetism and magnetic area of the magnet have been significantly improved.

[0026] In some embodiments, the magnet has an acting pole, and the acting pole is located at a predetermined position in the predetermined orientation magnetic field.

[0027] With such a setting, the content of the isotropic magnetic material at the acting pole of the magnet is higher, and the content of the isotropic magnetic material at the structure farther away from the acting pole position decreases, improving the utilization rate of the magnetic material, and the magnetic performance of the magnet is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a flowchart of the method for manufacturing a magnet in an embodiment of the present disclosure;

[0029] Figure 2 is a cross-sectional view of the predetermined orientation magnetic field mold in an embodiment of the present disclosure;

[0030] Figure 3 is a magnetic field diagram of the cross-section of the predetermined orientation magnetic field mold in an embodiment of the present disclosure;

[0031] Figure 4 is an overall structural diagram of the magnet in an embodiment of the present disclosure;

[0032] Figure 5 is a magnetic field waveform diagram of the magnet in an embodiment of the present disclosure.

[0033] Reference numerals:

[0034] 10. Magnet; 20. Predetermined orientation magnetic field mold; 21. Die sleeve; 22. Magnetic ring segment; 23. Mounting sleeve; 24. Mandrel. Specific embodiments

[0035] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

[0036] It should be noted that when a component is referred to as being "mounted on" another component, it can be directly on the other component or there may also be an intermediate component. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be an intermediate component at the same time. When a component is considered to be "fixed to" another component, it can be directly fixed to the other component or there may be an intermediate component at the same time.

[0037] The structural dimensions shown in the drawings herein do not represent the actual dimensions and may be adjusted as needed during actual production. The orientation terms "upper", "lower", "left", "right", etc. used herein refer to the orientation in the drawings and should not be construed as a limitation on the product during actual use unless clearly stated.

[0038] The first, second, third, etc. herein are only used to distinguish the same features. It can be understood that the first magnetic pole herein can also be referred to as the second magnetic pole, and the second magnetic pole can also be referred to as the first magnetic pole.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this disclosure belongs. The terms used in the specification of this disclosure herein are only for the purpose of describing specific embodiments and are not intended to limit this disclosure. The term "or / and" used herein includes any and all combinations of one or more of the related listed items.

[0040] Most of the magnetic rings of the magnetic rotor are made by injection molding neodymium iron boron, and almost all of the injection molded neodymium iron boron magnetic rings are injection molded with isotropic materials. The magnetic ring is magnetized after being assembled into the water pump rotor, but the magnetic properties of the magnetic ring need to be improved. In the conventional isotropic injection molded neodymium iron boron magnetic ring, there is a large amount of neodymium iron boron material that is not fully magnetized in the non-acting pole part, and reducing the content of the neodymium iron boron material in the non-acting pole part will not affect the performance of the magnetic ring.

[0041] Based on this, a method for manufacturing a magnet is provided to solve the problem that the magnetic properties of an injection-molded magnet made of isotropic material need to be improved.

[0042] As Figure 1 shown, Figure 1 the flowchart of the method 1000 for manufacturing a magnet in an embodiment of the present disclosure is shown. The method 1000 for manufacturing a magnet provided by the embodiment of the present disclosure includes the following steps S101 to step S102.

[0043] Step S101, in a predetermined orientation magnetic field environment, an injection-molded preformed magnet is formed based on magnet raw materials. Exemplarily, the magnet raw materials include isotropic magnetic materials and binders.

[0044] Step S102, demagnetize the preformed magnet. It can be understood that the structure formed in each step can still be used as the preformed structure for the next step. For example, it can be considered that step S102 forms a magnet, or other processing can continue after step S102.

[0045] For the method 1000 for manufacturing a magnet provided by the embodiment of the present disclosure, a predetermined orientation magnetic field environment is designed according to requirements, isotropic magnetic materials and adhesives are selected and placed in the predetermined magnetic field environment, and during the injection molding process of the preformed magnet, the isotropic magnetic materials are arranged and distributed according to the design of the predetermined orientation magnetic field. The content of the isotropic magnetic materials at the acting poles of the preformed magnet is increased, the content of the isotropic magnetic materials at the non-acting poles of the preformed magnet is reduced, the utilization rate of the isotropic magnetic materials is improved, and the performance of the preformed magnet is improved. Demagnetizing the preformed magnet is to eliminate the residual magnetism left after the preformed magnet is injection-molded in the predetermined orientation magnetic field environment.

[0046] The method provided by the embodiment of the present disclosure can form a magnet with low cost or high cost performance. The magnet realizes the non-uniform distribution of isotropic magnetic materials and realizes the improvement of magnetic properties.

[0047] Referring to Figure 2 , the method 1000 for manufacturing a magnet provided by the embodiment of the present disclosure can be executed by a predetermined orientation magnetic field mold 20. Exemplarily, the magnet 10 formed by the method 1000 can be a magnetic ring.

[0048] The mold sleeve 21 defines a cavity, and a plurality of magnetic ring segments 22 are mounted around the outer periphery of the mold sleeve 21 in a circumferential arrangement. The predetermined orientation magnetic field mold 20 has two magnetic poles pointing to the cavity at a predetermined position, which are the south pole and the north pole. The two magnetic poles cause the plurality of magnetic ring segments 22 to have different magnetic properties, thereby setting a predetermined orientation magnetic field. Step S101 is executed to fill the cavity of the predetermined orientation magnetic field mold 20 with isotropic magnetic material and binder, so that the isotropic magnetic material is unevenly distributed according to the design of the predetermined orientation magnetic field during the injection molding process of forming the magnet 10, ensuring the isotropic magnetic material near the acting pole. Then step S102 is executed to demagnetize the prefabricated magnet.

[0049] The method 1000 for manufacturing a magnet provided by an embodiment of the present disclosure forms a magnet 10 by injection molding in a magnetic field environment with a predetermined orientation. This magnet 10 can be used as a prefabricated magnet for the demagnetization step. This method 1000 increases the content of isotropic magnetic material at the acting pole of the magnet 10 and reduces the content of isotropic magnetic material at the non-acting pole of the prefabricated magnet, thereby improving the magnetic properties of the prefabricated magnet.

[0050] In some embodiments, the method further includes step S104: performing positioning magnetization on the prefabricated magnet that has undergone the demagnetization step.

[0051] With such a setting, compared with a magnet formed by ordinary injection molding and then demagnetized, the surface magnetic field and magnetic area of the prefabricated magnet formed by injection molding in a magnetic field environment with a predetermined orientation and then demagnetized are both greatly improved after positioning magnetization.

[0052] Exemplarily, design a predetermined orientation magnetic field environment according to requirements. Select isotropic magnetic material and place it in the predetermined magnetic field environment. During the injection molding process of forming the prefabricated magnet, the isotropic magnetic material is arranged and distributed according to the design of the predetermined orientation magnetic field. Then demagnetize the prefabricated magnet. Then perform positioning magnetization on the demagnetized prefabricated magnet. Then the magnetic properties of the magnet after positioning magnetization can be measured.

[0053] Exemplarily, the method further includes step S103: injection molding the prefabricated magnet into an impeller rotor. In some embodiments, the impeller rotor as a whole can also be referred to as the magnet 10.

[0054] In the method 1000 for manufacturing a magnet provided by an embodiment of the present disclosure, after step S102 is executed, step S103 is executed first, and then step S104 is executed. Then step S104 is to perform positioning magnetization on the impeller rotor formed by injection molding.

[0055] Exemplarily, a predetermined orientation magnetic field environment is designed according to requirements. An isotropic magnetic material is selected and placed in the predetermined magnetic field environment, and the isotropic magnetic material is arranged and distributed according to the design of the predetermined orientation magnetic field during the injection molding process to form a prefabricated magnet. Then, the prefabricated magnet is demagnetized. The demagnetized prefabricated magnet is placed in a rotor mold to form a rotor mold. Then, the impeller rotor is positioned and magnetized. Finally, the magnetic properties of the impeller rotor after positioning and magnetization are measured.

[0056] Exemplarily, when the impeller rotor is formed by injection molding, the prefabricated magnet is placed in the mold for blade injection molding, and the blade is injection molded above the prefabricated magnet. Plastic is filled in other vacant parts of the mold cavity according to the shape of the impeller rotor to form the impeller rotor.

[0057] It can be understood that the prefabricated magnet is a sub-component of the impeller rotor, and the prefabricated magnet is not damaged or changed. Therefore, the injection molding of the blade has no influence on the magnetic properties of the prefabricated magnet. In some other embodiments, it can be considered that the method 1000 has manufactured the magnet 10, and then the magnet 10 can be used for other subsequent processing, such as being used in the steps of the method for obtaining the impeller rotor by injection molding.

[0058] In some embodiments, the isotropic magnetic material includes neodymium iron boron material, and the binder includes polyphenylene sulfide.

[0059] With such a setting, the isotropic neodymium iron boron material in the magnet raw material can be arranged and distributed according to the design of the predetermined orientation magnetic field during the injection molding process, improving the utilization rate of the isotropic magnetic material and being beneficial to the improvement of the performance of the prefabricated magnet; and the formed distribution state can be maintained by using the binder.

[0060] Exemplarily, a predetermined orientation magnetic field environment is designed according to requirements. The neodymium iron boron material and polyphenylene sulfide are placed in the predetermined magnetic field environment, and the isotropic neodymium iron boron material is arranged and distributed according to the design of the predetermined orientation magnetic field during the injection molding process to form a neodymium iron boron prefabricated magnet. Then, the neodymium iron boron prefabricated magnet is demagnetized. The demagnetized neodymium iron boron prefabricated magnet is placed in a rotor mold to form a rotor mold. Then, the impeller rotor is positioned and magnetized. Finally, the magnetic properties of the impeller rotor after positioning and magnetization can be measured.

[0061] In some embodiments, the maximum magnetic energy product of the neodymium iron boron material ranges from 3.5 MGOe to 7 MGOe.

[0062] With such a setting, the cost of the magnet 10 formed by using the neodymium iron boron material is controllable, and the high magnetic requirements of the magnet 10 can be met with low-performance neodymium iron boron materials, or a magnet with higher performance can be achieved with neodymium iron boron materials of the same performance level. The price of the neodymium iron boron material is cheaper, which is beneficial to reducing costs and improving the competitive advantage.

[0063] Exemplarily, a predetermined orientation magnetic field environment is designed according to requirements. A neodymium iron boron material with a maximum magnetic energy product of 3.5 MGOe and polyphenylene sulfide are placed in the predetermined magnetic field environment, and the isotropic neodymium iron boron material is arranged and distributed according to the design of the predetermined orientation magnetic field during the injection molding process to form a neodymium iron boron preformed magnet. Then, the neodymium iron boron preformed magnet is demagnetized. The demagnetized neodymium iron boron preformed magnet is placed in a rotor mold to form a rotor mold. Then, the impeller rotor is positioned and magnetized. Finally, the magnetic properties of the impeller rotor after positioning and magnetization can be measured.

[0064] In other embodiments, the maximum magnetic energy product of the neodymium iron boron material can be 6 MGOe.

[0065] In some embodiments, the method further includes: filling the cavity of the predetermined orientation magnetic field mold 20 with magnet raw materials.

[0066] Wherein, the predetermined orientation magnetic field mold 20 is used to provide a predetermined orientation magnetic field, and the predetermined orientation magnetic field has at least two magnetic poles pointing to the cavity at a predetermined position, and the at least two magnetic poles include a south pole and a north pole.

[0067] With such a setting, at least two magnetic poles including the south pole and the north pole are beneficial to forming a predetermined orientation magnetic field, and further can enable the magnet raw materials in the cavity to form a preformed magnet that satisfies a sine wave.

[0068] Exemplarily, in step S101, a predetermined orientation magnetic field environment is provided by the predetermined orientation magnetic field mold 20 and a cavity is formed. The cavity of the predetermined orientation magnetic field mold 20 is filled with a neodymium iron boron material with a maximum magnetic energy product of 3.5 MGOe and polyphenylene sulfide, and the isotropic neodymium iron boron material is arranged and distributed according to the design of the predetermined orientation magnetic field during the injection molding process to form a neodymium iron boron preformed magnet. Then, the neodymium iron boron preformed magnet is demagnetized. The demagnetized neodymium iron boron preformed magnet is placed in a rotor mold to form an impeller rotor. Then, the impeller rotor is positioned and magnetized. Finally, the magnetic properties of the impeller rotor after positioning and magnetization can be measured.

[0069] Exemplarily, the predetermined orientation magnetic field mold 20 has at least two predetermined positions. The predetermined orientation magnetic field mold 20 has at least two isotropic magnetic structures injection molded in the base body, the predetermined positions of the isotropic magnet structures, and the density of the isotropic magnet structures gradually increases along the direction towards the predetermined positions.

[0070] In some embodiments, the predetermined orientation magnetic field mold 20 includes a mold sleeve 21 and a plurality of magnetic ring segments 22, and the mold sleeve 21 is used to define the cavity.

[0071] The method further includes: arranging and installing a plurality of magnetic ring segments 22 around the outer periphery of the mold sleeve 21, and setting the magnetic pole directions of each magnetic ring segment 22 to set the predetermined orientation magnetic field.

[0072] With such a setting, the magnetic poles of each magnetic ring segment 22 are directed to set a predetermined orientation magnetic field. A plurality of magnetic ring segments 22 are arranged in a circumferential manner around the outer periphery of the mold sleeve 21, so that the magnet raw material in the cavity is injection-molded into a prefabricated magnet according to requirements. This is beneficial to improving the utilization rate of isotropic magnetic materials and enhancing the performance of the prefabricated magnet.

[0073] Exemplarily, the mold sleeve 21 defines a cavity, and a plurality of magnetic ring segments 22 are installed in a circumferential arrangement around the outer periphery of the mold sleeve 21. The two magnetic poles of the predetermined orientation mold pointing to the cavity at a predetermined position are the south pole and the north pole. The two magnetic poles enable the plurality of magnetic ring segments 22 to have different magnetic properties, thereby setting a predetermined orientation magnetic field. A neodymium iron boron material with a maximum magnetic energy product of 3.5 MGOe and polyphenylene sulfide are filled into the cavity of the predetermined orientation magnetic field mold 20, and the isotropic neodymium iron boron material is arranged and distributed according to the design of the predetermined orientation magnetic field during the injection molding process to form a neodymium iron boron prefabricated magnet. Then, the neodymium iron boron prefabricated magnet is demagnetized. The demagnetized neodymium iron boron prefabricated magnet is placed into a rotor mold to form a rotor mold. Then, the impeller rotor is positioned and magnetized. Finally, the magnetic properties of the impeller rotor after positioning and magnetization are measured.

[0074] In some embodiments, the predetermined orientation magnetic field mold 20 is configured to have six magnetic poles.

[0075] With such a setting, the six magnetic poles can better form a predetermined orientation magnetic field environment. By increasing the content of magnetic materials at the acting poles, the performance of the prefabricated magnet is improved. The formed magnet has better circumferential performance.

[0076] Exemplarily, the mold sleeve 21 defines a cavity, and a plurality of magnetic ring segments 22 are installed in a circumferential arrangement around the outer periphery of the mold sleeve 21. The six magnetic poles of the predetermined orientation mold pointing to the cavity at a predetermined position are the south poles and the north poles arranged at intervals. The six magnetic poles enable the plurality of magnetic ring segments 22 to have different magnetic properties, thereby setting a predetermined orientation magnetic field. A neodymium iron boron material with a maximum magnetic energy product of 3.5 MGOe and polyphenylene sulfide are filled into the cavity of the predetermined orientation magnetic field mold 20, and the isotropic neodymium iron boron material is arranged and distributed according to the design of the predetermined orientation magnetic field during the injection molding process to form a neodymium iron boron prefabricated magnet. Then, the neodymium iron boron prefabricated magnet is demagnetized. The demagnetized neodymium iron boron prefabricated magnet is placed into a rotor mold to form a rotor mold. Then, the impeller rotor is positioned and magnetized. Finally, the magnetic properties of the impeller rotor after positioning and magnetization are measured.

[0077] Refer to Figure 3 and Figure 4, embodiments of the present disclosure provide a predetermined orientation magnetic field mold 20, which includes a mold sleeve 21 and a plurality of magnetic ring segments 22. The mold sleeve 21 is used to define a cavity. The plurality of magnetic ring segments 22 are arranged in a circumferential manner around the outer periphery of the mold sleeve 21, and the plurality of magnetic ring segments 22 are used to form a predetermined orientation magnetic field, which has at least two magnetic poles pointing to the cavity at a predetermined position, and the at least two magnetic poles include a south pole and a north pole.

[0078] The predetermined orientation magnetic field mold 20 provided by the embodiments of the present disclosure designs a predetermined orientation magnetic field and can be used to manufacture a magnet 10. The content of the isotropic magnetic material at the acting poles of the prefabricated magnet formed by using the predetermined orientation magnetic field mold 20 increases, and the content of the isotropic magnetic material at the non-acting poles decreases. The performance and competitiveness of the prefabricated magnet are improved.

[0079] Exemplarily, the predetermined orientation magnetic field mold 20 includes a mandrel 24, a mold sleeve 21, a ring magnetic segment, and a mounting sleeve 23 from the inside out. The outer wall of the mandrel 24 and the inner wall of the mold sleeve 21 define a cavity, which is used to place magnet raw materials and injection mold a prefabricated magnet. The plurality of magnetic ring segments 22 are arranged in a circumferential manner around the outer periphery of the mold sleeve 21. Opposite-polarity magnetic poles are arranged every 90 degrees between the plurality of magnetic ring segments 22 along the axial direction of the mandrel 24 to form a predetermined orientation magnetic field. The mounting sleeve 23 is sleeved on the outer periphery of the plurality of magnetic ring segments 22.

[0080] Exemplarily, the defined cavity is annular. In other embodiments, the mandrel 24 may not be provided so that the defined cavity is cylindrical.

[0081] Exemplarily, the mounting sleeve 23 is a steel sleeve. In other embodiments, the mounting sleeve 23 may also be, for example, a copper sleeve.

[0082] Exemplarily, the mold sleeve 21 is a steel sleeve, and the thickness of the mold sleeve 21 is less than the thickness of the mounting sleeve 23.

[0083] Refer to Figure 2 , exemplarily, there are twenty-four magnetic ring segments 22, and opposite-polarity magnetic poles are arranged every 90 degrees between the plurality of magnetic ring segments 22, so that each magnetic ring segment 22 has a different magnetism.

[0084] It can be understood that the number of the magnetic ring segments 22 can be adjusted according to requirements.

[0085] In some embodiments, there are twenty-four magnetic ring segments 22, and opposite-polarity magnetic poles are arranged every 60 degrees between the plurality of magnetic ring segments 22, so that four adjacent magnetic ring segments 22 between the two magnetic poles have the same polarity magnetism, and the magnetic ring segments 22 on both sides of each magnetic pole have opposite-polarity magnetism.

[0086] Refer to Figure 4, embodiments of the present disclosure provide a magnet 10, which is obtained by the steps of the above-mentioned method 1000 for manufacturing a magnet, or the magnet 10 is injection molded by the above-mentioned predetermined orientation magnetic field mold 20.

[0087] The magnet 10 provided by the embodiments of the present disclosure is formed by using isotropic magnetic raw materials in a predetermined orientation magnetic field environment. The isotropic magnetic materials in it are unevenly distributed, and the content of magnetic materials is higher near the structure at the preset position. The surface magnetism and magnetic area of the magnet 10 have been significantly improved.

[0088] In some embodiments, the magnet 10 has an acting pole, and the acting pole is located at a predetermined position in the predetermined orientation magnetic field.

[0089] With such a setting, the content of isotropic magnetic materials at the acting pole of the magnet 10 is higher, and the content of isotropic magnetic materials at the structure farther away from the acting pole position decreases, improving the utilization rate of magnetic materials, and the magnetic performance of the magnet 10 is significantly improved.

[0090] Exemplarily, refer to Figure 5 , the sampling waveform of the magnet 10 is a sine wave, and the N pole and the S pole alternate. The part with magnetic performance between the two zero position lines of the N pole or the S pole is the acting pole, and the magnetic performance of the acting part close to the zero position line is weak. The highest magnetic performance is in the middle of the two zero position lines.

[0091] The magnet 10 can be formed by using a mold with a predetermined orientation magnetic field as shown in Figure 3 .

[0092] It can be understood that the magnetic strength of the prefabricated magnet is determined by the predetermined orientation magnetic field.

[0093] Exemplarily, an isotropic neodymium iron boron material with a maximum magnetic energy product of 3.5 MGOe and polyphenylene sulfide particles are used to injection mold an isotropic unoriented magnet A 0 and an oriented magnet A 1 in a mold without a predetermined orientation magnetic field and a mold with a predetermined orientation magnetic field respectively. 0 and an oriented magnet B 1 are injection molded by using an isotropic neodymium iron boron material with a maximum magnetic energy product of 6 MGOe and polyphenylene sulfide particles in a mold without a predetermined orientation magnetic field and a mold with a predetermined orientation magnetic field respectively.

[0094] Magnet A 0 and magnet B 0 are not magnetized, and magnet A 1 and magnet B 1 are magnetized. Magnet A 1 and magnet B 1 are demagnetized respectively. Then magnet A0 , magnet B 0 and the demagnetized magnet A 1 and magnet B 1 are placed into the same impeller rotor mold, injection molded to form a rotor with an impeller, and the impeller rotor is positioned and magnetized under the same conditions to obtain magnet A 0 ’, magnet A 1 ’, magnet B 0 ’ and magnet B 1 ’. Among them, magnet A 0 ’ and magnet B 0 ’ are non-oriented magnets, and magnet A 0 ’ and magnet B 0 ’ are oriented magnets.

[0095] Next, magnet A 0 ’, magnet A 1 ’, magnet B 0 ’ and magnet B 1 ’ are placed into the same magnetic property comprehensive tester. Two products are in each group, and the surface magnetism and magnetic area of the magnetic rings are respectively tested. The test data are averaged, and the specific values are shown in Table 1.

[0096] Table 1

[0097]

[0098] Referring to Table 1, for the magnets made of NdFeB material with a maximum magnetic energy product of 3.5 MGOe, the surface magnetism of the oriented magnet A 1 ’ is 13.08% higher than that of the non-oriented magnet A 0 ’, and the magnetic area of the oriented magnet A 1 ’ is 12.24% higher than that of the non-oriented magnet A 0 ’.

[0099] For the magnets made of NdFeB material with a maximum magnetic energy product of 6 MGOe, the surface magnetism of the oriented magnet B 1 ’ is 14.69% higher than that of the non-oriented magnet B 0 ’, and the magnetic area of the oriented magnet B 1 ’ is 12.82% higher than that of the non-oriented magnet B 0 ’. For the magnets obtained by the above method for manufacturing magnets, the surface magnetism and magnetic area of the magnets have been significantly improved.

[0100] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0101] The various forms of the processes described above can be used, and steps can also be reordered, added, or deleted. The steps recorded in the embodiments of the present disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired results of the technical solutions provided by the embodiments of the present disclosure can be achieved, and no limitations are imposed herein.

[0102] The above-described embodiments merely represent several implementation manners of the present disclosure. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the disclosed patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present disclosure, several modifications and improvements can still be made, and these all fall within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure patent shall be subject to the appended claims.

Claims

1. A method for producing a magnet, characterized in that include: In a predetermined orientation magnetic field environment, forming a prefabricated magnet based on a magnet raw material by injection molding, wherein the magnet raw material includes an isotropic magnetic material and a binder; and The prefabricated magnet is demagnetized.

2. The method for manufacturing a magnet according to claim 1, wherein: Also includes: The prefabricated magnet that has undergone the demagnetization step is subjected to positioning magnetization.

3. The method for manufacturing a magnet according to claim 1, wherein: The isotropic magnetic material includes neodymium iron boron material, and the binder includes polyphenylene sulfide.

4. The method for manufacturing a magnet according to claim 3, wherein: The maximum magnetic energy product of the NdFeB material is in the range of 3.5 MGOe to 7 MGOe.

5. The method for manufacturing a magnet according to claim 1, wherein: Also includes: Filling the magnet raw material into the cavity of a mold with a predetermined orientation magnetic field; Wherein, the predetermined orientation magnetic field mold is used to provide the predetermined orientation magnetic field, and the predetermined orientation magnetic field has at least two magnetic poles pointing to the cavity at a predetermined position, and the at least two magnetic poles include a south pole and a north pole.

6. The method for manufacturing a magnet according to claim 5, wherein: The predetermined orientation magnetic field mold comprises a mold sleeve and a plurality of magnetic ring segments, wherein the mold sleeve is used to define the mold cavity; The method further includes: installing the plurality of magnetic ring segments in a surrounding arrangement on the outer periphery of the mold sleeve, and setting the magnetic pole orientation of each of the magnetic ring segments to set the predetermined orientation magnetic field.

7. The method for manufacturing a magnet according to claim 5, wherein: The predetermined orientation magnetic field mold is configured to have six magnetic poles to form a magnet with six active poles.

8. A predetermined orientation magnetic field mold, characterized in that: include: A mold sleeve, used to define the cavity; as well as A plurality of magnetic ring segments are arranged around the outer periphery of the mold sleeve, and the plurality of magnetic ring segments are used to form a predetermined orientation magnetic field. The predetermined orientation magnetic field has at least two magnetic poles pointing to the mold cavity at a predetermined position, and the at least two magnetic poles include a south pole and a north pole.

9. A magnet, characterized in that The magnet is manufactured by the steps of the method for manufacturing a magnet according to any one of claims 1 to 7, or the magnet is obtained by injection molding according to the predetermined oriented magnetic field mold according to claim 8.

10. The magnet according to claim 9, wherein The magnet has an active pole, and the active pole is located at a predetermined position in the predetermined orientation magnetic field.

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