Pouring forming process of inductor

Abstract

The invention belongs to the technical field of electronic equipment, and particularly relates to a pouring forming process of an inductor. A pouring forming process of an inductor comprises the following steps that S1, a conductor coil (2) with a bent part (3) is prepared; s2, the conductor coil (2) is placed in a cavity of a pouring mold (1), then a pouring material composite material is poured into the cavity of the pouring mold (1) through a pouring runner, and a preliminary product of the poured inductor is obtained; and S3, carrying out curing treatment on the primary product of the cast inductor obtained in the S2 to obtain a finished product of the cast inductor. According to the pouring forming process of the inductor, the problems that due to the fact that iron powder at the bent positions of the two ends of an existing conductor is not pressed compactly, the side wall is prone to cracking after the inductor is formed, and the reliability and the yield are low due to the fact that large forming pressure is required in the process of pressing forming are solved, and the obtained pouring forming process of the inductor is simple; the inductor is excellent in performance, and the yield of the poured inductor is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of electronic equipment, and more specifically, relates to a casting molding process for an inductor. Background Art

[0002] Inductors, also known as inductor coils, can convert electrical energy into magnetic energy and store it. They are one of the basic components of electronic circuits and are widely used in electronic circuits. Existing one-piece molded inductors include a magnetic core and a winding body. The magnetic core is formed by burying the winding body in metal magnetic powder by die-casting. The winding body is usually a single-layer or multi-layer coil covered with lacquer film, or a single linear conductor. The coil and the conductor are pressed in the middle of the magnetic powder through a cold process or a hot process, and then the glue in the magnetic powder is solidified through a baking process to form an inductor product with a certain strength.

[0003] However, with the advancement of 5G technology, the power supply units in server chips begin to need to use higher-frequency one-piece molded inductors, with frequencies of 500Khz and above. As the frequency increases, the inductor loss produced by the traditional one-piece molded inductor process increases significantly, and the inductors produced by the traditional one-piece molded inductor process are no longer suitable for the power supply needs of servers. In order to reduce the DC resistance of the inductor, it is usually necessary to increase the overall thickness or width of the conductor and achieve it through pressing and molding. However, the two ends of the conductor are exposed to the outside of the magnetic core as terminals, and the parts that serve as terminals need to be bent. The overall thickness of the conductor is relatively thick, which makes it difficult to bend the parts of the conductors at both ends as terminals. The iron powder at the bends of the two ends of the conductor is not compacted, which makes it easy for the side walls of the inductor to crack after molding. In addition, the process requires a large molding pressure during pressing and molding, which may cause the coil to deform and the insulation layer of the wire to break, resulting in low reliability and yield rate. In addition, the casting material particles are subjected to greater directional pressure during pressing, generating unidirectional stress. Therefore, the uniformity in size and weight is poor, resulting in large deviations in the amount of powder filled into each cavity of the mold during the molding stage, which is difficult to control. As a result, the pressed inductor has large performance deviations and cannot tightly cover the inductor coil, ultimately significantly reducing the product yield and resulting in poor inductor effectiveness. Summary of the invention

[0004] In view of the problem that in the existing inductor preparation process, magnetic powder is not compacted firmly, resulting in low cavity space utilization and poor inductance performance, the present application provides a casting molding process for an inductor.

[0005] In a first aspect, the present application provides a casting molding process for an inductor, which adopts the following technical solution: A casting molding process for an inductor comprises the following steps: S1: preparing a conductor coil having a bending portion; S2: placing the conductor coil in the casting mold cavity, and then pouring the casting material composite material into the casting mold cavity through the casting runner to obtain a preliminary casting inductor product; S3: Curing the preliminary cast inductor product obtained in S2 to obtain a finished cast inductor product.

[0006] By adopting the above technical solution, by preparing a conductor coil with a bent portion, the bent portion is convenient for the conductive portion to contact, and by the above casting molding instead of hot pressing molding, the components in the inductor will not be subjected to mechanical impact, avoiding the side wall from cracking easily after the inductor is formed, making the pressure in each direction uniform, ensuring reliability during use, and in addition, the casting material magnetic powder is uniformly stressed in each direction, avoiding the generation of large directional pressure, reducing the directionality of stress, ensuring that the magnetic properties of the inductor will not be greatly affected, the inductance loss is small, and the core loss can be greatly reduced. The liquid metal of the inductor coil and the outer casting mold are solidified and formed into a whole, which avoids the problem of unstable structure of the inductor coil and ensures that the strength of the inductor is high and the inductor performance is excellent.

[0007] In a specific embodiment, the conductor coil is one or more archway coils.

[0008] By adopting the above technical solution, the arch coil is arranged so that the bending parts are arranged on both sides of the arch coil and are led out to the outside of the magnet through the bending parts, thus avoiding the problem of the coil end lead wire being inside the magnet and occupying the internal space of the magnet in the traditional technology, so that the magnetic powder content is higher in the magnet of equal volume, the outer diameter of the conductor coil is increased, and the insulation performance of the inductor is improved, thereby improving the performance of the inductor. In addition, the bending parts extend outward to both sides of the arch, so that the external placement of the lead wire can avoid the risk of the inductor coil contacting with the lead wire and causing a short circuit during operation, thereby improving the safety performance of the inductor element.

[0009] In a specific possible implementation manner, the conductor coil is one or more combined coils, and the combined coil is a main and a secondary combined coil with the inner wall of the main coil attached to the secondary coil.

[0010] By adopting the above technical solution, one or more combined coils are arranged, and the inner wall of the main coil of the combined coil is attached to the secondary coil, so that the conductor coils of the inductor are coupled to meet different voltage regulation ratio requirements; in addition, the secondary coil is attached to the inner wall of the main coil, which increases the outer diameter of the conductor coil, improves the insulation performance of the inductor, and improves the space utilization of the overall conductor inductance, so that a relatively large amount of magnetic powder can be cast to ensure the inductance performance of the material.

[0011] In a specific possible implementation manner, the bending portion of the main coil is bent outward, and the bending portion of the secondary coil is bent inward.

[0012] By adopting the above technical solution, the bent parts that bend outward and inward not only help the inductance performance of the inductor and avoid short circuit caused by contact between the bent parts of the main and secondary coils, but also the main coil is facing outward and the secondary coil is facing inward, which helps to improve the stability of the combined coil during the casting process and improve the yield rate.

[0013] In a specific implementation manner, the size of the casting mold cavity in S2 is larger than the size of the inductor coil; the inner radial cross-sectional area of ​​the conductor coil is 20-28% of the transverse cross-sectional area of ​​the casting mold.

[0014] By adopting the above technical solution, the inductor coil is placed in the casting mold cavity so that the cross-section of the extended bent portion is on the surface of the magnet, thereby ensuring the inductance and saturation characteristics of the inductor coil. The present application discloses the ratio of the internal radial cross-sectional area of ​​the conductor coil to the transverse cross-sectional area of ​​the casting mold, so that the insulation performance is relatively better and the energy loss is smaller.

[0015] In a specific possible implementation scheme, the casting mold in S2 is provided with perforations, each of which is provided with a casting flow channel, and the perforations are located on both sides or the upper part of the bottom of the casting mold.

[0016] By adopting the above technical solution and a casting method from top to bottom or from bottom to top, the casting material is evenly distributed in the casting mold cavity, avoiding the influence of uneven material distribution on the coil stability and inductance performance, improving the yield rate, and avoiding the problem of loose magnetic powder between the combined coils.

[0017] In a specific implementation scheme, the curing treatment in S3 is a heating curing treatment, and the cast inductor preliminary product is baked at a temperature of 120-150° C. for 1-3 hours.

[0018] In a specific embodiment, the particle size of the casting material in S1 is 50-80 mesh.

[0019] By adopting the above technical solution, the particle size of the casting material disclosed in the present application is more conducive to casting to form a denser magnet, especially, it is conducive to filling the intersection of the combined coils, improving the space utilization rate in the casting mold cavity, further increasing the saturation magnetic flux density of the material and thus improving the magnetic permeability.

[0020] An inductor is prepared by the casting molding process of the inductor.

[0021] In summary, this application has the following beneficial effects: 1. By preparing a conductor coil with a bent portion, the bent portion is convenient for the conductive portion to contact. The casting molding is not hot pressing molding, so that the components in the inductor will not be subjected to mechanical impact, avoiding the side wall from cracking after the inductor is formed, making the pressure in all directions uniform, ensuring reliability during use. In addition, the magnetic powder of the casting material is uniformly stressed in all directions, avoiding the generation of large directional pressure, reducing the directionality of stress, ensuring that the magnetic properties of the inductor will not be greatly affected, the inductance loss is small, and the core loss can be greatly reduced. The liquid metal of the inductor coil and the outer casting mold are solidified and formed into a whole, which avoids the problem of unstable structure of the inductor coil and ensures that the strength of the inductor is high and the inductor performance is excellent.

[0022] 2. By setting up the arch coil, the bends are set on both sides of the arch coil and are led out to the outside of the magnet through the bends. This avoids the problem of the coil end lead being inside the magnet and occupying the internal space of the magnet in the traditional technology, so that the magnetic powder content is higher in the magnet of equal volume, the outer diameter of the conductor coil is increased, and the insulation performance of the inductor is improved, thereby improving the performance of the inductor. In addition, the bends extend outward to both sides of the arch, so that the external placement of the lead can avoid the risk of the inductor coil contacting the lead during operation and causing a short circuit, thereby improving the safety performance of the inductor component.

[0023] 3. By setting one or more combined coils, the inner wall of the main coil of the combined coil is attached to the secondary coil, so that the conductor coil of the inductor is coupled to meet the requirements of different voltage regulation ratios; in addition, the secondary coil is attached to the inner wall of the main coil, which increases the outer diameter of the conductor coil, improves the insulation performance of the inductor, and improves the space utilization of the overall conductor inductance, so that a relatively large amount of magnetic powder can be cast to ensure the inductance performance of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the inductor provided in Example 1 of the present application.

[0025] Figure 2 It is a schematic diagram of the structure of the inductor element provided in Example 1 of the present application.

[0026] Figure 3 It is a schematic diagram of the structure of the inductor element provided in Example 6 of the present application.

[0027] Explanation of the accompanying drawings: 1. casting mold; 2. conductor coil; 3. bending part; 4. arch coil; 5. combined coil; 51. main coil; 52. auxiliary coil; 222. perforation; 33. casting material. DETAILED DESCRIPTION

[0028] The present application is further described in detail below with reference to the embodiments.

[0029] Some raw materials used in the preparation examples and embodiments: epoxy resin brand: sc-1; the diluent is acetone; curing agent model: T-31.

[0030] The raw materials used in the examples and comparative examples that are not otherwise specified are all conventional products that can be purchased from the market.

[0031] Example 1 like Figure 1 and Figure 2 As shown, a casting inductor comprises a casting mold 1 having a cubic structure with a perforation 222 provided at the upper opening, a casting flow channel provided on the perforation 222, and an arch coil 4 centrally placed in the mold cavity of the casting mold 1. The casting mold 1 is injected with casting material 33, which is prepared by including iron silicon aluminum powder and passivation agent, insulating agent, adhesive, and diluent, and is injected until it is flush with the edge of the upper opening of the casting mold 1. The casting mold 1, the arch coil 4, and the casting material 33 are integrally cast, and the two ends of the bending portion 3 of the arch coil 4 are respectively led out from the arch coil 4. The arch coil 4 is wound by a flat copper wire, and the coil is placed in the casting mold 1, and the two ends of the bending portion 3 of the arch coil 4 are respectively extended to be led out from the casting mold 1 to form an electrode end.

[0032] Casting material 33: Fe-Si-Al powder with an average particle size of 60 mesh is coated to obtain composite soft magnetic alloy powder; A casting molding process for an inductor, S1: preparing a conductor coil 2 with a bending portion 3; S2: placing the conductor in a casting mold 1 cavity, and then pouring a casting material 33 into the casting mold 1 cavity through a casting runner to obtain a preliminary casting inductor product; S3: baking the preliminary casting inductor product obtained in S2 at 120° C. for 1 hour for curing treatment to obtain a finished casting inductor product, wherein the inner radial cross-sectional area of ​​the arch coil 4 is 20% of the transverse cross-sectional area of ​​the casting mold 1.

[0033] Example 2 The difference between this embodiment and embodiment 1 is that, casting material 33: Fe-Si-Al powder with an average particle size of 80 mesh is coated to obtain composite soft magnetic alloy powder; A casting molding process for an inductor, S1: preparing a conductor coil 2 with a bending portion 3; S2: placing the conductor in a casting mold 1 cavity, and then pouring a casting material 33 into the casting mold 1 cavity through a casting runner to obtain a preliminary casting inductor product; S3: baking the preliminary casting inductor product obtained in S2 at 120° C. for 1 hour for curing treatment to obtain a finished casting inductor product, wherein the inner radial cross-sectional area of ​​the arch coil 4 is 20% of the transverse cross-sectional area of ​​the casting mold 1.

[0034] Example 3 The difference between this embodiment and embodiment 1 is that, casting material 33: Fe-Si-Al powder with an average particle size of 120 mesh is coated to obtain composite soft magnetic alloy powder; A casting molding process for an inductor, S1: preparing a conductor coil 2 with a bending portion 3; S2: placing the conductor in a casting mold 1 cavity, and then pouring a casting material 33 into the casting mold 1 cavity through a casting runner to obtain a preliminary casting inductor product; S3: baking the preliminary casting inductor product obtained in S2 at 120° C. for 1 hour for curing treatment to obtain a finished casting inductor product, wherein the inner radial cross-sectional area of ​​the arch coil 4 is 20% of the transverse cross-sectional area of ​​the casting mold 1.

[0035] Example 4 The difference between this embodiment and embodiment 1 is that, casting material 33: Fe-Si-Al powder with an average particle size of 60 mesh is coated to obtain composite soft magnetic alloy powder; A casting molding process for an inductor, S1: preparing a conductor coil 2 with a bending portion 3; S2: placing the conductor in a casting mold 1 cavity, and then pouring a casting material 33 into the casting mold 1 cavity through a casting runner to obtain a preliminary casting inductor product; S3: baking the preliminary casting inductor product obtained in S2 at 120° C. for 1 hour for curing treatment to obtain a finished casting inductor product, wherein the inner radial cross-sectional area of ​​the arch coil 4 is 28% of the transverse cross-sectional area of ​​the casting mold 1.

[0036] Example 5 The difference between this embodiment and embodiment 1 is that a casting molding process of an inductor is provided, S1: preparing a conductor coil 2 with a bending portion 3; S2 placing the conductor in a casting mold 1 cavity, and then pouring a casting material 33 into the casting mold 1 cavity through a casting flow channel to obtain a preliminary cast inductor product; S3: baking the preliminary cast inductor product obtained in S2 at 120° C. for 1 hour for curing treatment to obtain a cast inductor finished product, wherein the inner radial cross-sectional area of ​​the arch coil 4 is 38% of the transverse cross-sectional area of ​​the casting mold 1.

[0037] Example 6 The difference between this embodiment and embodiment 1 is that Figure 1 and Figure 3As shown, a cast inductor comprises a casting mold 1 having a cubic structure with openings on both sides of the bottom and perforations 222, and a casting flow channel on the perforations 222, and a combined coil 5 placed in the mold cavity of the casting mold 1. The casting mold 1 is injected with casting material 33, which is prepared by including sendustine powder and passivation agent, insulating agent, adhesive, and diluent, and is injected until it is flush with the edge of the upper opening of the casting mold 1. The casting mold 1, the combined coil 5, and the casting material 33 are integrally cast and formed, and the two ends of the bending portion 3 of the main coil 51 of the combined coil 5 are respectively led out from the combined coil 5, and the secondary coil 52 is bent inward at the bending portion 3. The bending portion 3 of the main coil 51 and the bending portion 3 of the secondary coil 52 form an R space, thereby improving the overall stability of the combined coil 5. The combined coil 5 is wound by flat copper wire, and the coil is placed in the casting mold 1. The two ends of the bending portion 3 of the main coil 51 are respectively extended to be led out from the casting mold 1 to form an electrode end.

[0038] Casting material 33: Fe-Si-Al powder with an average particle size of 60 mesh is coated to obtain composite soft magnetic alloy powder; A casting molding process for an inductor, S1: preparing a conductor coil 2 with a bending portion 3; S2: placing the conductor in a casting mold 1 cavity, and then pouring a casting material 33 into the casting mold 1 cavity through a casting runner to obtain a preliminary casting inductor product; S3: baking the preliminary casting inductor product obtained in S2 at 120° C. for 1 hour for curing treatment to obtain a finished casting inductor product, wherein the inner radial cross-sectional area of ​​the arch coil 4 is 20% of the transverse cross-sectional area of ​​the casting mold 1.

[0039] Example 7 The difference between this embodiment and the embodiment 1 is that a cast inductor comprises a casting mold 1 having a cubic structure with openings on both sides of the bottom and perforations 222, and a casting flow channel on the perforations 222, and a combination coil 5 placed in the mold cavity of the casting mold 1. The casting mold 1 is injected with casting material 33, and the casting material 33 is prepared by including sendustine powder and passivation agent, insulating agent, adhesive, and diluent, and is injected until it is flush with the edge of the upper opening of the casting mold 1. The casting mold 1, the combination coil 5 and the casting material 33 are integrally cast and formed, and the two ends of the bending portion 3 of the main coil 51 of the combination coil 5 are respectively led out from the combination coil 5, and the auxiliary coil 52 is bent inward at the bending portion 3. The bending portion 3 of the main coil 51 and the bending portion 3 of the auxiliary coil 52 form an R space, thereby improving the overall stability of the combination coil 5. The combination coil 5 is wound by flat copper wire, and the coil is placed in the casting mold 1. The two ends of the bending portion 3 of the main coil 51 are respectively extended to be led out from the casting mold 1 to form an electrode end.

[0040] Casting material 33: Fe-Si-Al powder with an average particle size of 100 mesh is coated to obtain composite soft magnetic alloy powder; A casting molding process for an inductor, S1: preparing a conductor coil 2 with a bending portion 3; S2: placing the conductor in a casting mold 1 cavity, and then pouring a casting material 33 into the casting mold 1 cavity through a casting runner to obtain a preliminary casting inductor product; S3: baking the preliminary casting inductor product obtained in S2 at 120° C. for 1 hour for curing treatment to obtain a finished casting inductor product, wherein the inner radial cross-sectional area of ​​the arch coil 4 is 20% of the transverse cross-sectional area of ​​the casting mold 1.

[0041] Example 8 The difference between this embodiment and the embodiment 1 is that a casting inductor comprises a casting mold 1 having a cubic structure with a perforation 222 provided at the upper opening, a casting flow channel provided on the perforation 222, and a combination coil 5 centrally placed in the mold cavity of the casting mold 1. The casting mold 1 is injected with a casting material 33, and the casting material 33 is prepared by including sendustine powder and a passivator, an insulating agent, an adhesive, and a diluent, and is injected until it is flush with the edge of the upper opening of the casting mold 1. The casting mold 1, the combination coil 5, and the casting material 33 are integrally cast and formed, and the two ends of the bending portion 3 of the main coil 51 of the combination coil 5 are respectively led out from the combination coil 5, and the auxiliary coil 52 is bent inward at the bending portion 3. The bending portion 3 of the main coil 51 and the bending portion 3 of the auxiliary coil 52 form an R space, thereby improving the overall stability of the combination coil 5. The combination coil 5 is wound by a flat copper wire, and the coil is placed in the casting mold 1. The two ends of the bending portion 3 of the main coil 51 are respectively extended to be led out from the casting mold 1 to form an electrode end.

[0042] Casting material 33: Fe-Si-Al powder with an average particle size of 60 mesh is coated to obtain composite soft magnetic alloy powder; A casting molding process for an inductor, S1: preparing a conductor coil 2 with a bending portion 3; S2: placing the conductor in a casting mold 1 cavity, and then pouring a casting material 33 into the casting mold 1 cavity through a casting runner to obtain a preliminary casting inductor product; S3: baking the preliminary casting inductor product obtained in S2 at 120° C. for 1 hour for curing treatment to obtain a finished casting inductor product, wherein the inner radial cross-sectional area of ​​the arch coil 4 is 20% of the transverse cross-sectional area of ​​the casting mold 1.

[0043] Comparative Example Comparative Example 1 An inductor includes a casting mold 1 of a cubic structure with an upper opening, and an arch coil 4 centrally placed in the mold cavity of the casting mold 1. The casting mold 1 is filled with casting material 33, which includes sendustine powder and a passivator, an insulating agent, an adhesive, and a diluent. The casting material 33 is injected until it is flush with the edge of the upper opening of the casting mold 1. The casting mold 1, the arch coil 4, and the casting material 33 are integrally cast, and the two ends of the bending portion 3 of the arch coil 4 are respectively led out from the arch coil 4. The arch coil 4 is wound with a flat copper wire, and the coil is placed in the casting mold 1. The two ends of the bending portion 3 of the arch coil 4 extend to be led out from the casting mold 1 to form an electrode end.

[0044] Casting material 33: Fe-Si-Al powder with an average particle size of 60 mesh is coated to obtain composite soft magnetic alloy powder; A casting molding process for an inductor, S1: preparing a conductor coil 2 with a bending portion 3; S2: hot pressing molding: placing the above-mentioned casting material 33 in a hot pressing mold, performing hot pressing molding, obtaining an integrally formed first inductor blank, and baking the first inductor blank to obtain a baked inductor.

[0045] Comparative Example 2 A cast inductor comprises a casting mold 1 of a cubic structure with an upper opening, and an arch coil 4 centrally placed in the cavity of the casting mold 1. A casting material 33 is injected into the casting mold 1, and the casting material 33 comprises sendustine powder and a passivator, an insulating agent, an adhesive, and a diluent. The casting material 33 is injected until it is flush with the edge of the upper opening of the casting mold 1. The casting mold 1, the coil, and the casting material 33 are integrally cast. The coil is wound by flat copper wire, and the coil is placed in a casting mold 1; casting material 33: Fe-Si-Al powder with an average particle size of 60 mesh is coated to obtain a composite soft magnetic alloy powder; a casting molding process for an inductor, S1: preparing a coil; S2: placing a conductor in a casting mold 1 cavity, and then pouring a casting material 33 into the casting mold 1 cavity through a casting channel to obtain a preliminary product of a cast inductor; S3: baking the preliminary product of the cast inductor obtained in S2 at 120°C for 1h for curing treatment to obtain a finished cast inductor, and the inner radial cross-sectional area of ​​the arch coil 4 is 20% of the transverse cross-sectional area of ​​the casting mold 1.

[0046] Performance Testing The performance test of the cast inductor prepared in the embodiment and the comparative example adopts the following method: The test process is: 100kHz effective magnetic permeability μe: A precision magnetic analyzer is used to measure the effective magnetic permeability μe at a frequency of 100kHz, and the test voltage is fixed at 1V.

[0047] Loss Pc at 50kHz / 50mT: The volume loss Pc at a frequency of 50kHz and a magnetic flux density of 50mT is measured using an AC loss test system; the comparison results are shown in Table 1 below: Table 1 Performance test results 100kHz effective permeability μe Yield rate (%) <![CDATA[Power loss Pc (mW / cm -3 )]]> Example 1 54.2 99 48.9 Example 2 53.8 97 47.6 Example 3 49.7 96 49.5 Example 4 54.6 99 44.2 Example 5 46.8 98 50.7 Example 6 66.9 97 45.5 Example 7 51.9 96 48.7 Example 8 62.6 98 46.8 Comparative Example 1 25.8 75 78.5 Comparative Example 2 39.5 71 88.6 It can be seen from Table 1 that the casting molding process of the inductor obtained in the above embodiment meets the requirements of high effective magnetic permeability, small eddy current loss and inductance performance, has a high yield rate, and does not cause cracks in the side wall after molding.

[0048] Compared with Comparative Examples 1-2 and Example 1, the effective magnetic permeability and eddy current loss index of the casting molding process of an inductor prepared in Example 1 are better than those of Comparative Examples 1-2. It is analyzed that by preparing a conductor coil with a bent portion, the bent portion is convenient for the conductive portion to contact, and the components in the inductor are not subjected to mechanical impact force by casting molding instead of hot pressing molding, which avoids the side wall from cracking easily after the inductor is formed, improves the yield rate, ensures that the magnetic properties of the inductor will not be greatly affected, the inductance loss is small, and the core loss is greatly reduced. The liquid metal of the inductor coil and the outer casting mold are solidified and formed into a whole, which avoids the problem of unstable structure of the inductor coil, ensures that the strength of the inductor is high, and the inductor performance is excellent.

[0049] By comparing Examples 6-7, it can be seen that the effective magnetic permeability and eddy current loss indicators of the casting molding process of an inductor prepared in Example 6 are better than those in Example 7. It is analyzed that the particle size of the casting material disclosed in the present application is more conducive to casting to form a denser magnet, especially, it is conducive to filling the intersection of the combined coils, improving the space utilization rate in the casting mold cavity, further increasing the saturation magnetic flux density of the material and thus improving the magnetic permeability.

[0050] By comparing Example 1 with Examples 4-5, it can be seen that the effective magnetic permeability and eddy current loss indicators of the casting molding process of an inductor prepared in Example 1 and Example 4 are better than those in Example 5. Analysis shows that the inductor coil is placed in the casting mold cavity so that the cross-section of the extended bent portion is on the surface of the magnet, ensuring the inductance and saturation characteristics of the inductor coil. The ratio of the internal radial cross-sectional area of ​​the conductor coil disclosed in the present application to the transverse cross-sectional area of ​​the casting mold makes the insulation performance relatively better and the energy loss smaller.

[0051] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A casting molding process for an inductor, characterized in that: The following steps are included: S1: preparing a conductor coil (2) having a bending portion (3); S2: placing the conductor coil (2) in the cavity of the casting mold (1), and then pouring the casting material composite material into the cavity of the casting mold (1) through the casting flow channel to obtain a preliminary cast inductor product; S3: Curing the preliminary cast inductor product obtained in S2 to obtain a finished cast inductor product.

2. The casting molding process of the inductor according to claim 1, characterized in that: The conductor coil (2) is one or more arch coils (4).

3. The casting molding process of the inductor according to claim 1, characterized in that: The conductor coil (2) is one or more combined coils (5), and the combined coil (5) is a main and auxiliary combined coil (5) in which the inner wall of the main coil (51) is attached to the auxiliary coil (52).

4. The casting molding process of the inductor according to claim 3, characterized in that: The bending portion (3) of the main coil (51) is bent outwards, and the bending portion (3) of the secondary coil (52) is bent inwards.

5. The casting molding process of the inductor according to claim 1, characterized in that: The size of the casting mold (1) cavity in S2 is larger than the size of the inductor coil; the inner radial cross-sectional area of ​​the conductor coil (2) is 20-28% of the transverse cross-sectional area of ​​the casting mold (1).

6. The casting molding process of the inductor according to claim 1, characterized in that: The casting mold (1) in S2 is provided with perforations (222), each of which is provided with a casting flow channel, and the perforations (222) are located on both sides of the bottom or the upper part of the casting mold (1).

7. The casting molding process of the inductor according to claim 1, characterized in that: The curing treatment in S3 is a heating curing treatment, and the cast inductor preliminary product is baked at a temperature of 120-150° C. for 1-3 hours.

8. The casting molding process of the inductor according to claim 1, characterized in that: The particle size of the casting material in S1 is 50-80 mesh.

9. An inductor manufactured by the casting molding process of the inductor according to any one of claims 1 to 8.

Images