High magnetic field permanent magnet orientation structure formed based on injection molding samarium cobalt magnet

Abstract

The invention discloses a high magnetic field permanent magnet orientation structure based on injection molding samarium-cobalt magnet molding, which comprises a polygonal first center magnet and a polygonal second center magnet, a lower mold orientation group is arranged outside the first center magnet, an upper mold orientation group is arranged outside the second center magnet, and according to the magnet structure and arrangement of the upper mold orientation group and the lower mold orientation group, the high magnetic field permanent magnet orientation structure is formed. The orientation of the N pole and the S pole is adjusted, the orientation magnetic field intensity of the permanent magnet orientation process is remarkably improved, and the problem of orientation unsaturation of a high-coercivity material is solved. The structure adopts a full permanent magnet orientation design, and compared with an electromagnetic orientation device, the mold manufacturing cost and the energy consumption cost are reduced by 30%.

Description

Technical Field

[0001] This invention belongs to the field of magnetic orientation technology, specifically relating to a high magnetic field permanent magnet orientation structure based on injection-molded samarium cobalt magnets. Background Technology

[0002] Permanent magnet orientation is the core process for manufacturing high-performance permanent magnet materials (such as neodymium iron boron). Essentially, it involves using an external magnetic field to align the easy magnetization axes (such as the c-axis) of magnetic powder particles in the same direction, thereby improving key performance indicators such as remanence, coercivity, and maximum energy product of the magnet.

[0003] Orientation structure is a key structure in the injection molding of anisotropic magnets. Existing orientation structures are divided into permanent magnet orientation and electromagnetic orientation. Permanent magnet orientation mostly uses a single orientation structure, and the orientation magnetic field strength is mostly between 0.4 and 0.8T, which can easily cause unsaturated orientation degree of high coercivity materials. Although electromagnetic orientation can obtain a higher orientation field, it has disadvantages such as high energy consumption, high cost, and high heat loss because it consumes more than 5 kWh of electricity per molding and requires a cooling system to control the temperature rise of the coil. Summary of the Invention

[0004] The purpose of this invention is to provide a high magnetic field permanent magnet orientation structure based on injection-molded samarium cobalt magnets, so as to solve the problem of orientation magnetic field strength in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A high magnetic field permanent magnet orientation structure includes a polygonal first central magnet and a second central magnet. A lower mold orientation group is mounted outside the first central magnet, and an upper mold orientation group is mounted outside the second central magnet.

[0006] Preferably, the first and second central magnets of the polygon are regular octagons.

[0007] Preferably, the lower mold orientation group includes a first orientation permanent magnet, which is equidistantly arrayed on the outer wall of the first central magnet. A first magnetically conductive orientation block is installed on the right side of the first central magnet, and a magnetically conductive lower cavity is installed on the right side of the first magnetically conductive orientation block. The outer sides of the first orientation permanent magnets are all N poles and the inner sides are all S poles, and the left side of the first central magnet is an N pole and the right side is an S pole.

[0008] Preferably, the upper mold orientation assembly includes a second orientation permanent magnet, which is equidistantly arrayed on the outer wall of the second central magnet. A second magnetically conductive orientation block is mounted on the left side of the second central magnet, and a magnetically conductive top block is mounted on the left side of the second magnetically conductive orientation block. A magnetically conductive upper cavity is mounted on the left side of the magnetically conductive top block. The outer sides of the second orientation permanent magnet are all S poles, and the inner sides are all N poles. The left side of the second central magnet is an N pole, and the right side is an S pole.

[0009] Preferably, a magnetic core rod is installed inside the lower mold orientation assembly. The magnetic core rod passes through the first central magnet, the first magnetic orientation block, and the magnetic lower mold cavity, and then enters the magnetic upper mold cavity for connection.

[0010] Preferably, the first oriented permanent magnet, the first central magnet, the second oriented permanent magnet, and the second central magnet are sintered neodymium iron boron magnets.

[0011] Preferably, both the first and second oriented permanent magnets have dovetail grooves at their tail ends. The dovetail groove design facilitates positioning with the mold panel.

[0012] In a preferred method, samarium cobalt granules are injected into the cavity formed by the magnetic upper cavity and the magnetic core rod through an injection molding machine, and oriented and molded into a samarium cobalt injection-molded magnet under the magnetic field generated by the permanent magnet orientation structure. Samarium-cobalt granules are based on metallic samarium (Sm), electrolytic cobalt (Co), and alloying elements (Fe, Cu, Zr) with a purity ≥99%; 24%-26% Sm; 48%-52% Co, 5%-7% Cu, 3%-5% Zr, and the balance Fe. After proportioning, the Sm2Co17-30 alloy was obtained by high-temperature melting and casting in a vacuum melting furnace. The alloy was then coarsely and mediumly crushed under argon protection to break the ingot into smaller particles, which were then fed into a fluidized bed jet mill for ultrafine grinding using high-pressure nitrogen. The particle size was controlled by a classifying wheel, and the magnetic powder particle size distribution was controlled within the range of D10: 1.3~2.3μm, D50: 4.4~7.4μm, and D90: 8~14μm. Finally, the particles were screened using a 100-mesh sieve to obtain Sm2Co17-30 magnetic powder. The magnetic powder was mixed with 10% PA12 binder by weight and granulated at high temperature using a parallel twin-screw extruder at a granulation temperature of 190~230℃, a main machine speed of 150rpm, and a melt pressure of 4.5Mpa. The resulting high coercivity granules had typical magnetic properties of Br: 5.7KGs, Hcj: 15.5KOe, and (BH)max: 7.3MGOe.

[0013] The technical solution of this invention has the following beneficial effects: 1. By adjusting the orientation of the N and S poles according to the magnet structure and arrangement of the upper and lower mold orientation groups, the magnetic field strength of the permanent magnet orientation process is significantly improved, solving the problem of unsaturated orientation of high coercivity materials. This structure adopts a fully permanent magnet orientation design, which reduces mold manufacturing and energy consumption costs by 30% compared to electromagnetic orientation devices. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0016] Figure 2 This is a schematic diagram of the lower mold orientation structure of the present invention.

[0017] Figure 3 This is a schematic diagram of the upper mold orientation structure of the present invention.

[0018] Figure 4 This is a schematic diagram of the measurement of the internal magnetic field strength of the permanent magnet orientation structure of the present invention.

[0019] Figure 5 This is a schematic diagram showing the simulated position and surface magnetic measurement position of the samarium cobalt granules of the present invention.

[0020] Figure 6 This is a theoretical magnetic field diagram of the samarium-cobalt granules under saturated orientation according to the present invention.

[0021] Reference numerals: 10, First orientation permanent magnet; 101, First central magnet; 102, First magnetically conductive orientation magnetic block; 103, Magnetically conductive lower cavity; 104, Magnetically conductive core rod; 20. Second orientation permanent magnet; 201. Second central magnet; 202. Second magnetic orientation magnet block; 203. Magnetic top block; 204. Magnetic upper cavity; 30. Samarium cobalt injection molded magnet. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0023] Example 1: refer to Figures 1-3 A high magnetic field permanent magnet orientation structure based on injection-molded samarium cobalt magnets includes a polygonal first central magnet 101 and a second central magnet 201. A lower mold orientation group is installed outside the first central magnet 101, and an upper mold orientation group is installed outside the second central magnet 201.

[0024] The first central magnet 101 and the second central magnet 201 of the polygon are regular octagons.

[0025] The lower mold orientation group includes a first orientation permanent magnet 10, the first orientation permanent magnet 10 is equidistantly arrayed on the outer wall of the first central magnet 101, a first magnetically conductive orientation magnetic block 102 is installed on the right side of the first central magnet 101, and a magnetically conductive lower cavity 103 is installed on the right side of the first magnetically conductive orientation magnetic block 102. Reference 1 and Figure 2 The outer side of the first oriented permanent magnet 10 is N pole and the inner side is S pole, and the left side of the first central magnet 101 is N pole and the right side is S pole.

[0026] In the above scheme, based on the magnetic pole distribution direction of the first oriented permanent magnet 10 (both outer sides are N poles and inner sides are S poles) and the first central magnet 101 (left side is N pole and right side is S pole), combined with the first magnetically guided oriented magnetic block 102 and the magnetically guided lower cavity 103, the magnetic lines of force of the first central magnet 101 and the first oriented permanent magnet 10 converge at the magnetically guided lower cavity 103.

[0027] refer to Figure 1 and Figure 3 The upper mold orientation group includes a second orientation permanent magnet 20. The second orientation permanent magnets 20 are equidistantly arrayed on the outer wall of the second central magnet 201. A second magnetically conductive orientation magnetic block 202 is installed on the left side of the second central magnet 201. A magnetically conductive top block 203 is installed on the left side of the second magnetically conductive orientation magnetic block 202. A magnetically conductive upper cavity 204 is installed on the left side of the magnetically conductive top block 203. The second oriented permanent magnet 20 has S poles on the outside and N poles on the inside, while the second central magnet 201 has N poles on the left and S poles on the right.

[0028] In the above scheme, based on the magnetic pole distribution direction of the second oriented permanent magnet 20 (both outer sides are S poles and inner sides are N poles) and the second central magnet 201 (left side is N pole and right side is S pole), combined with the second magnetically oriented magnetic block 202 and the magnetically oriented top block 203, the magnetic lines of force of the second oriented permanent magnet 20 and the second central magnet 201 converge at the magnetically oriented top block 203.

[0029] Preferably, a magnetic core rod 104 is installed inside the lower mold orientation assembly. The magnetic core rod 104 passes through the first central magnet 101, the first magnetic orientation block 102, and the magnetic lower cavity 103, and enters the magnetic upper cavity 204 for connection. After the injection mold is closed, the magnetic core rod 104 and the magnetic lower cavity 103 contact the magnetic top block 203 and the magnetic upper cavity 204 to form a magnetic circuit, thereby creating a 1.5T orientation field on the surface of the cavity. In summary, by adjusting the orientation of the N and S poles based on the magnet structure and arrangement of the upper and lower mold orientation groups, the magnetic field strength of the permanent magnet orientation process was significantly improved, solving the problem of unsaturated orientation in high-coercivity materials. This structure adopts a fully permanent magnet orientation design, reducing mold manufacturing and energy consumption costs by 30% compared to electromagnetic orientation devices.

[0030] Example 2: refer to Figure 2 and Figure 3 The first oriented permanent magnet 10, the first central magnet 101, the second oriented permanent magnet 20, and the second central magnet 201 are made of sintered neodymium iron boron magnets.

[0031] In the above scheme, neodymium iron boron magnets (grade N45UH and above) are used, with flat end faces to improve magnetic properties and enhance structural stability.

[0032] Preferred Solution Reference Figure 2 and Figure 3 Both the first-oriented permanent magnet 10 and the second-oriented permanent magnet 20 have dovetail grooves at their tail ends. The dovetail groove design facilitates positioning with the mold panel.

[0033] Specifically, the first magnetic orientation block 102, the magnetic lower cavity 103, the magnetic core rod 104, the second magnetic orientation block 202, the magnetic top block 203, and the magnetic upper cavity 204 are made of magnetic materials (SKD / SKH series).

[0034] Example 3: refer to Figure 4 The assembled product is shown in the diagram, which is a measurement data image of the internal magnetic field strength of the permanent magnet orientation structure obtained from finite element simulation.

[0035] Example 4: refer to Figures 1-6 Samarium cobalt granules are injected into the cavity formed by the magnetic upper cavity 204 and the magnetic core rod 104 through an injection molding machine, and are oriented and molded into a samarium cobalt injection-molded magnet 30 under the magnetic field generated by the permanent magnet orientation structure. Samarium-cobalt granules are based on metallic samarium (Sm), electrolytic cobalt (Co), and alloying elements (Fe, Cu, Zr) with a purity ≥99%; 24%-26% Sm; 48%-52% Co, 5%-7% Cu, 3%-5% Zr, and the balance Fe. After proportioning, the Sm2Co17-30 alloy was obtained by high-temperature melting and casting in a vacuum melting furnace. The alloy was then coarsely and mediumly crushed under argon protection to break the ingot into smaller particles, which were then fed into a fluidized bed jet mill for ultrafine grinding using high-pressure nitrogen. The particle size was controlled by a classifying wheel, and the magnetic powder particle size distribution was controlled within the range of D10: 1.3~2.3μm, D50: 4.4~7.4μm, and D90: 8~14μm. Finally, the particles were screened using a 100-mesh sieve to obtain Sm2Co17-30 magnetic powder. The magnetic powder was mixed with 10% PA12 binder by weight and granulated at high temperature using a parallel twin-screw extruder at a granulation temperature of 190~230℃, a main machine speed of 150rpm, and a melt pressure of 4.5Mpa. The resulting high coercivity granules had typical magnetic properties of Br: 5.7KGs, Hcj: 15.5KOe, and (BH)max: 7.3MGOe.

[0036] The samarium cobalt injection-molded magnet 30 obtained by the above method has a design size of D11XD7XD3X8 (M). Based on the performance of this granule, finite element simulation was used, and the simulation location is as follows. Figure 5 As shown, under the premise of saturated orientation, the surface magnetism of the product at a distance of 0.1mm from the end face is approximately 2060Gs. Based on the above permanent magnet orientation structure, the mold was designed. Using a 120T injection molding machine with an injection temperature of 240~270℃, an injection pressure of 90Bar, an injection speed of 60g / s, and an injection time of 2S, the product was formed. The actual measured surface magnetism using a gaussmeter was approximately between 1950~2040GS, and the actual orientation saturation was 97%. This data indicates that the high orientation field of the permanent magnet orientation structure is sufficient to saturate and magnetize high coercivity plastic magnetic materials.

[0037] Samarium cobalt granules are a high-coercivity injection molding material obtained by processing samarium cobalt magnets into magnetic powder and then granulating them. This material is used in conjunction with an orientation structure to injection mold products in order to verify the orientation saturation. Therefore, the purpose of samarium cobalt granule injection molding products is to practically verify the effectiveness of the orientation structure.

[0038] The above embodiments are merely exemplary models of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Various modifications or equivalent substitutions can be made to the present invention within its spirit and scope of protection. Such modifications or equivalent substitutions should also be considered to fall within the scope of protection of the present invention.

[0039] In the description of this invention, it should be noted that the terms "inner," "front," "rear," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the appended circle, or the orientation or positional relationship in which the product of this invention is conventionally placed during use. They are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, these terms indicating orientation or positional relationships should not be construed as limitations on the invention.

[0040] In the description of this invention, it should be further noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, these terms can refer to a fixed connection, a detachable connection, or an integral connection between elements; they can also refer to a mechanical connection or an electrical connection; or they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of these terms in this invention according to the specific circumstances.

Claims

1. A high-magnetic-field permanent magnet orientation structure based on injection-molded samarium cobalt magnets, characterized in that: It includes a first central magnet (101) and a second central magnet (201) that are polygonal in shape. A lower mold orientation group is installed outside the first central magnet (101), and an upper mold orientation group is installed outside the second central magnet (201).

2. The high magnetic field permanent magnet orientation structure based on injection-molded samarium cobalt magnets according to claim 1, characterized in that: The first central magnet (101) and the second central magnet (201) of the polygon are regular octagons.

3. A high-magnetic-field permanent magnet orientation structure based on injection-molded samarium cobalt magnets according to claim 2, characterized in that: The lower mold orientation group includes a first orientation permanent magnet (10), the first orientation permanent magnet (10) is equidistantly arrayed on the outer wall of the first central magnet (101), a first magnetically conductive orientation magnetic block (102) is installed on the right side of the first central magnet (101), and a magnetically conductive lower cavity (103) is installed on the right side of the first magnetically conductive orientation magnetic block (102).

4. A high-magnetic-field permanent magnet orientation structure based on injection-molded samarium cobalt magnets according to claim 3, characterized in that: The first oriented permanent magnet (10) has N poles on the outside and S poles on the inside, and the first central magnet (101) has N poles on the left and S poles on the right.

5. A high-magnetic-field permanent magnet orientation structure based on injection-molded samarium cobalt magnets according to claim 4, characterized in that: The upper mold orientation group includes a second orientation permanent magnet (20), the second orientation permanent magnet (20) is equidistantly arrayed on the outer wall of the second central magnet (201), a second magnetically conductive orientation magnetic block (202) is installed on the left side of the second central magnet (201), a magnetically conductive top block (203) is installed on the left side of the second magnetically conductive orientation magnetic block (202), and a magnetically conductive upper cavity (204) is installed on the left side of the magnetically conductive top block (203).

6. A high-magnetic-field permanent magnet orientation structure based on injection-molded samarium cobalt magnets according to claim 5, characterized in that: The second oriented permanent magnet (20) has S poles on the outside and N poles on the inside, and the second central magnet (201) has N poles on the left and S poles on the right.

7. A high-magnetic-field permanent magnet orientation structure based on injection-molded samarium cobalt magnets according to claim 6, characterized in that: The lower mold orientation assembly is equipped with a magnetic core rod (104). The magnetic core rod (104) passes through the first central magnet (101), the first magnetic orientation block (102) and the magnetic lower cavity (103). The magnetic core rod (104) enters the magnetic upper cavity (204) for connection.

8. A high-magnetic-field permanent magnet orientation structure based on injection-molded samarium cobalt magnets according to claim 5, characterized in that: The first oriented permanent magnet (10), the first central magnet (101), the second oriented permanent magnet (20), and the second central magnet (201) are sintered neodymium iron boron magnets.

9. A high-magnetic-field permanent magnet orientation structure based on injection-molded samarium cobalt magnets according to claim 5, characterized in that: The tail ends of the first oriented permanent magnet (10) and the second oriented permanent magnet (20) are both provided with dovetail grooves.

10. A method for granulating samarium cobalt granules is developed based on a high-magnetic-field permanent magnet orientation structure formed by injection molding of samarium cobalt magnets, characterized in that: Samarium cobalt granules are injected into the cavity formed by the magnetic upper cavity (204) and the magnetic core rod (104) through an injection molding machine, and are oriented and formed into a samarium cobalt injection-molded magnet (30) under the magnetic field generated by the above permanent magnet orientation structure. Samarium-cobalt granules are based on metallic samarium (Sm), electrolytic cobalt (Co), and alloying elements (Fe, Cu, Zr) with a purity ≥99%; 24%-26% Sm; 48%-52% Co, 5%-7% Cu, 3%-5% Zr, and the balance Fe. After proportioning, the Sm2Co17-30 alloy was obtained by high-temperature melting and casting in a vacuum melting furnace. The alloy was then coarsely and mediumly crushed under argon protection to break the ingot into smaller particles, which were then fed into a fluidized bed jet mill for ultrafine grinding using high-pressure nitrogen as the power source. The particle size was controlled by a classifying wheel, and the magnetic powder particle size distribution was controlled within the range of D10: 1.3~2.3μm, D50: 4.4~7.4μm, and D90: 8~14μm. Finally, the particles were screened using a 100-mesh sieve to obtain Sm2Co17-30 magnetic powder. The magnetic powder was mixed with 10% PA12 binder by weight and granulated at high temperature using a parallel twin-screw extruder at a granulation temperature of 190~230℃, a main machine speed of 150rpm, and a melt pressure of 4.5Mpa. The resulting high coercivity granules had typical magnetic properties of Br: 5.7KGs, Hcj: 15.5KOe, and (BH)max: 7.3MGOe.

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