Common mode inductor and method of making the same

Abstract

The application discloses a common mode inductor and a preparation method thereof, and relates to the technical field of inductor production. The common mode inductor comprises a first magnetic core, a second magnetic core and two coils. The first magnetic core has a first middle column and two first side columns arranged on the two sides of the first middle column. The second magnetic core is arranged separately from the first magnetic core. The second magnetic core has a second middle column and two second side columns arranged on the two sides of the second middle column. Each first side column is in abutment with a second side column to cooperatively form a long side column. The first middle column and the second middle column are spaced apart. The two coils are respectively sleeved on the two long side columns. The application solves the problems of limited winding space of the winding and difficulty in automatic winding, improves the production efficiency, and ensures the consistency of product quality.

Description

Technical Field

[0001] This invention relates to the field of inductor manufacturing technology, and in particular to a common-mode inductor and its preparation method. Background Technology

[0002] Common-mode inductors typically employ a toroidal core structure with a dividing post in the middle of the core to separate the core into two posts. Two windings are wound on the two posts respectively to suppress common-mode interference signals.

[0003] However, because the dividing post in the middle of the toroidal core structure occupies the winding space, the radial dimension of the winding space is limited. Existing automated winding equipment is difficult to complete the winding operation in the narrow winding space. Therefore, in actual production, operators usually need to manually wind the windings one by one onto the two magnetic posts on both sides of the core.

[0004] However, manual winding is not only time-consuming and labor-intensive, but it is also difficult to ensure the consistency of the number of turns, tension and wiring neatness of the two windings, which leads to large fluctuations in the performance parameters of the common mode inductor, which is not conducive to mass production. Summary of the Invention

[0005] The main objective of this invention is to propose a common-mode inductor and its preparation method, which aims to solve the problems of limited winding space and difficulty in automating winding, thereby improving production efficiency and ensuring product quality consistency.

[0006] To achieve the above objectives, the present invention proposes a common-mode inductor, wherein the common-mode inductor comprises: A first magnetic core, comprising a first central post and two first side posts disposed on either side of the first central post; a second magnetic core. The second magnetic core is separately disposed from the first magnetic core. The second magnetic core has a second central post and two second side posts disposed on both sides of the second central post. Each first side post abuts against one of the second side posts to form a long side post, and there is a gap between the first central post and the second central post; and Two coils are respectively fitted onto the two long side posts.

[0007] In one embodiment, each coil has two pins that extend in a direction perpendicular to the axial direction of the long side post, and the free ends of the two pins face the same side.

[0008] In one embodiment, the common mode inductor further includes a winding member, which is wound around the outer periphery of the first magnetic core and the second magnetic core and is disposed corresponding to the first central post and the second central post, for tightening and fixing the first magnetic core and the second magnetic core.

[0009] In one embodiment, an adhesive layer is provided between each coil and the corresponding long side post for bonding the coil to the long side post.

[0010] This invention also proposes a method for fabricating a common-mode inductor, the method comprising: A first magnetic core and a second magnetic core are provided. The first magnetic core has a first central post and two first side posts disposed on both sides of the first central post. The second magnetic core has a second central post and two second side posts disposed on both sides of the second central post. Two coils are provided; The two coils are respectively fitted onto the two first side posts; The first magnetic core and the second magnetic core are relatively closed, so that each of the first side posts abuts against a second side post to form a long side post, and there is a gap between the first middle post and the second middle post; and The two coils are fixed to the corresponding long side post.

[0011] In one embodiment, the step of relatively closing the first magnetic core and the second magnetic core includes: Align the two first side posts with the two second side posts respectively; and The first and second center posts are wrapped with a winding material so that the first side post abuts against the corresponding second side post.

[0012] In one embodiment, the wrapping element is tape, strapping, sleeve, or clamp.

[0013] In one embodiment, the step of fixing the two coils to the corresponding long side post includes: The pins of the two coils are inserted into the limiting slots of the fixture, so that the first magnetic core and the second magnetic core are suspended and supported by the fixture; and The coil is bonded to the corresponding long side post using an adhesive layer.

[0014] In one embodiment, the step of bonding the coil to the corresponding long post using an adhesive layer includes: injecting an adhesive between the coil and the long post, and curing the adhesive.

[0015] In one embodiment, each of the coils is a prefabricated cylindrical coil having a central through hole.

[0016] The common-mode inductor of this invention includes a first magnetic core and a second magnetic core that are separately configured. The first magnetic core has a first central post and two first side posts disposed on its two sides. The second magnetic core has a second central post and two second side posts disposed on its two sides. During fabrication, two coils are first fitted onto the two first side posts of the first magnetic core, and then the first and second magnetic cores are brought together so that the first and second side posts abut against each other to form long side posts. Simultaneously, a gap is maintained between the first and second central posts, thereby positioning the two coils on the long side posts on their respective sides. This configuration, because the first and second magnetic cores are separately configured, allows the coils to be prefabricated using automated equipment before assembly, eliminating the need for manual winding in confined spaces, improving production efficiency, ensuring coil consistency, and enhancing product quality stability. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of a toroidal magnetic core structure; Figure 2 This is a schematic diagram of the structure of an embodiment of the common-mode inductor provided by the present invention; Figure 3 Exploded view of a common-mode inductor; Figure 4 This is a schematic diagram of the fixture structure; Figure 5 This is a schematic diagram of the structure when a common-mode inductor is placed in a fixture.

[0019] Explanation of icon numbers: 100. Common mode inductor; 1. First magnetic core; 11. First center post; 12. First side post; 13. Long side post; 2. Second magnetic core; 21. Second center post; 22. Second side post; 3. Coil; 31. Pin; 32. Center through hole; 4. Fixture; 41. Limiting slot; 200. Toroidal magnetic core structure; 201. Winding; 202. Separator post; 203. Magnetic post; 204. Winding space.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0023] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0024] like Figure 1 As shown, common-mode inductors typically employ a toroidal core structure 200, with a dividing post 202 in the middle of the core to divide the core into two posts 203. Two windings 201 are wound on the two posts 203 respectively to suppress common-mode interference signals.

[0025] However, since the dividing post 202 in the middle of the toroidal core structure 200 occupies the winding space 204, the radial dimension of the winding space 204 is limited. Existing automated winding equipment is difficult to complete the winding operation of the winding 201 in the narrow winding space 204. Therefore, in actual production, operators usually need to manually wind the winding 201 one by one onto the two magnetic posts 203 on both sides of the core.

[0026] However, manual winding is not only time-consuming and labor-intensive, but it is also difficult to ensure the consistency of the number of turns, tension and wiring neatness of the two windings 201, which leads to large fluctuations in the performance parameters of the common mode inductor, which is not conducive to mass production.

[0027] To address the aforementioned issues, this invention proposes a common-mode inductor 100 and its fabrication method, aiming to solve the problems of limited winding space and difficulty in automated winding of the winding 201, thereby improving production efficiency and ensuring consistent product quality.

[0028] Please see Figure 2 and Figure 3 In one embodiment of the present invention, the common-mode inductor 100 includes a first magnetic core 1, a second magnetic core 2, and two coils 3. The first magnetic core 1 has a first central post 11 and two first side posts 12 disposed on both sides of the first central post 11. The second magnetic core 2 is separately disposed from the first magnetic core 1. The second magnetic core 2 has a second central post 21 and two second side posts 22 disposed on both sides of the second central post 21. Each first side post 12 abuts against a second side post 22 to form a long side post 13, and there is a gap between the first central post 11 and the second central post 21. The two coils 3 are respectively sleeved on the two long side posts 13.

[0029] In this embodiment, the first magnetic core 1 and the second magnetic core 2 are separately arranged, with two first side posts 12 respectively located on opposite sides of the first central post 11, so that the cross-section of the first magnetic core 1 has an E-shaped structure. The second magnetic core 2 has a similar structure to the first magnetic core 1, with two second side posts 22 respectively located on opposite sides of the second central post 21, so that the cross-section of the second magnetic core 2 also has an E-shaped structure. When the first magnetic core 1 and the second magnetic core 2 are closed relative to each other along the mating direction, the end face of the first side post 12 abuts against the end face of the corresponding second side post 22, splicing together to form a long side post 13 extending along the axial direction, thereby providing a base for the coil 3 to be fitted. Meanwhile, a gap is provided between the first central column 11 and the second central column 21. During subsequent assembly, the winding component is wound around the corresponding outer periphery of the first central column 11 and the second central column 21. This gap provides a tightening allowance for the winding component, allowing it to apply opposing tension forces to the first magnetic core 1 and the second magnetic core 2 when tightened. This ensures that the contact surfaces of the first side column 12 and the second side column 22 are tightly fitted, guaranteeing reliable contact between the first side column 12 and the second side column 22. The two coils 3 are each independently mounted on the long side column 13 formed by splicing the first side column 12 and the second side column 22, thus positioning them respectively on the winding areas on both sides of the magnetic core after the first magnetic core 1 and the second magnetic core 2 are joined.

[0030] Understandably, this application, by disassembling the magnetic core into two independent components, a first magnetic core 1 and a second magnetic core 2, allows the coil 3 to be pre-fitted onto the first side post 12 before the first magnetic core 1 and the second magnetic core 2 are joined. Then, assembly is completed simply by joining the second magnetic core 2. Simultaneously, the spacing between the first central post 11 and the second central post 21 serves a dual purpose. Firstly, this spacing creates an air gap within the first magnetic core 1 and the second magnetic core 2, increasing the magnetic reluctance of the magnetic circuit and thus preventing magnetic saturation under DC bias, optimizing the electromagnetic performance of the common-mode inductor 100. Secondly, this spacing provides radial tightening clearance for the winding component, allowing it to apply opposing clamping forces to the first magnetic core 1 and the second magnetic core 2 when wound around the outer periphery of the first central post 11 and the second central post 21. This ensures tight contact between the end faces of the first side post 12 and the second side post 22, guaranteeing structural stability.

[0031] In one embodiment, the abutting end faces of the first side post 12 and the second side post 22 can be set as mutually parallel planar structures, or as mutually cooperating stepped surfaces, inclined surfaces, or concave and convex surfaces, in order to improve the stability after docking, without specific limitations.

[0032] It should be noted that, regarding the material selection for the first magnetic core 1 and the second magnetic core 2, those skilled in the art can refer to the conventional design methods of common mode inductor 100 magnetic cores in the prior art to determine the selection. For example, manganese-zinc ferrite, nickel-zinc ferrite, metal magnetic powder cores, or other materials with suitable permeability and loss characteristics can be selected. The material selection and ratio can also be adjusted according to the actual operating frequency, saturation magnetic flux density, and temperature characteristics. Since the specific selection of the magnetic core material is a conventional technical means in this field and does not affect the realization of the core inventive point of this application, no specific limitation is made here.

[0033] In one embodiment, each coil 3 is a prefabricated cylindrical coil 3 having a central through hole 32.

[0034] In this embodiment, the cylindrical coil 3 that meets the requirements can be directly processed by an automatic winding device. The cylindrical coil 3 has a central through hole 32 that runs through its interior along the axial direction. The inner diameter of the central through hole 32 is slightly larger than the outer diameter of the long side post 13 formed after the first side post 12 and the second side post 22 abut together, so that the cylindrical coil 3 can be directly sleeved on the long side post 13 along the axial direction through the central through hole 32.

[0035] In one embodiment, the cross-section of the columnar coil 3 is set to be circular, elliptical, square or other irregular shape, and the cross-sectional shape of the long side column 13 is adapted to the cross-sectional shape of the columnar coil 3.

[0036] In one embodiment, the central through hole 32 is a cylindrical hole structure, and the long side post 13 is a cylindrical post structure. In this case, the inner diameter of the coil 3 is 0.1 mm to 1.0 mm larger than the outer diameter of the long side post 13, so as to take into account both assembly convenience and positioning accuracy.

[0037] In one embodiment, the coil 3 can be formed by tightly winding enameled round copper wire; alternatively, it can be formed by vertically winding or overlapping flat copper wire. Meanwhile, the outer surface of the cylindrical coil 3 can be covered with insulating tape, impregnated with insulating varnish, or fitted with heat-shrink tubing to enhance insulation performance.

[0038] In one embodiment, the axial length of the coil 3 is equal to or slightly less than the axial length of the long side post 13, so that the two ends of the coil 3 can respectively abut against the bodies of the first magnetic core 1 and the second magnetic core 2, thus serving as a limiting function. At the same time, when the axial length of the coil 3 is slightly less than the axial length of the long side post 13, it is convenient for the pins 31 at both ends of the coil 3 to be led out.

[0039] In one implementation, please refer to Figure 3 , Figure 4 and Figure 5 Each coil 3 has two pins 31, which extend in a direction perpendicular to the axial direction of the long side post 13, and the free ends of the two pins 31 face the same side.

[0040] In this embodiment, the two pins 31 of each coil 3 are led outward from the coil 3 body and extend in a direction perpendicular to the axial direction of the long side post 13. The free ends of the two pins 31 are set to face the same side, so that the coil 3 has a uniform wire output direction after being sleeved on the long side post 13.

[0041] Understandably, this setup not only facilitates the installation of coil 3 in a fixed posture on the long side post 13 formed by the first magnetic core 1 and the second magnetic core 2, but also provides a structural basis for inserting pin 31 into the limiting groove 41 of the fixture 4, ensuring that the first magnetic core 1 and the second magnetic core 2 can obtain stable suspended support through pin 31 during the assembly process.

[0042] In one embodiment, along the extension direction of the long side post 13, the two pins 31 at one end of the two coils 3 are close to each other and located on the side where the two long side posts 13 are close to each other. The two pins 31 at the other end of the two coils 3 are far apart from each other and located on the side where the two long side posts 13 are far apart from each other, thereby forming a pin 31 layout that is symmetrical about the direction of the central post axis to improve stability when suspended.

[0043] Understandably, by setting the pins 31 of the two coils 3 to be close to each other at one end and far apart at the other end, it is equivalent to forming a support span of varying width at both ends of the common mode inductor 100. With the limiting groove 41 of the fixture 4, a support structure similar to a trapezoid or triangle can be formed, avoiding the swaying that may occur when the four support points are distributed in a rectangular shape. This allows the first magnetic core 1 and the second magnetic core 2 to maintain better stability in the suspended support state, which is convenient for subsequent operations.

[0044] In one embodiment, the distance between two pins 31 that are close to each other is 0.5 mm to 5 mm, and the distance between two pins 31 that are far apart from each other is 10 mm to 30 mm.

[0045] In one embodiment, the common mode inductor 100 further includes a winding member, which is wound around the outer periphery of the first magnetic core 1 and the second magnetic core 2 and is disposed corresponding to the first central post 11 and the second central post 21, for tightening and fixing the first magnetic core 1 and the second magnetic core 2.

[0046] In this embodiment, the winding member surrounds the outer peripheral surface of the first magnetic core 1 and the second magnetic core 2 after they are closed together, and the winding position of the winding member corresponds to the docking area of ​​the first central post 11 and the second central post 21. Since there is a gap between the first central post 11 and the second central post 21, the winding member can cross the gap and apply a circumferential clamping force when winding, thereby applying opposing tension forces to the first magnetic core 1 and the second magnetic core 2, so that the abutting end faces of the first side post 12 and the second side post 22 are kept in close contact, preventing the first magnetic core 1 and the second magnetic core 2 from separating relative to each other in subsequent processes.

[0047] In one embodiment, the width of the winding member is 5 mm to 20 mm to cover the mating area of ​​the first center post 11 and the second center post 21.

[0048] In one embodiment, the outer surface of the winding member is wrapped with an insulating sleeve or coated with insulating varnish to prevent the outer periphery of the first magnetic core 1 and the second magnetic core 2 from contacting other conductive components.

[0049] In one embodiment, the winding element is an adhesive tape, a binding strap, a sleeve, or a clamp. When the winding element is an adhesive tape, it can adhere to the outer periphery of the first magnetic core 1 and the second magnetic core 2 by relying on the adhesiveness and extensibility of the tape itself. When a binding strap is used, a circumferential binding force can be applied by mechanical binding. When a sleeve is used, the entire mating area of ​​the central pillars of the first magnetic core 1 and the second magnetic core 2 can be fitted into a tubular component with elastic contraction or rigid constraint. When a clamp is used, an annular clamp is used to wrap around the corresponding outer periphery of the first central pillar 11 and the second central pillar 21, generating a fastening force through radial contraction. Regardless of the form used, the winding element acts on the corresponding outer periphery of the first central pillar 11 and the second central pillar 21, using the gap between the first central pillar 11 and the second central pillar 21 to provide a tightening allowance, applying opposing tension forces to the first magnetic core 1 and the second magnetic core 2, thereby ensuring that the abutting end faces of the first side pillar 12 and the second side pillar 22 remain tightly fitted.

[0050] In one embodiment, an adhesive layer is provided between each coil 3 and the corresponding long side post 13 for bonding the coil 3 to the long side post 13.

[0051] In this embodiment, the adhesive layer is filled between the inner wall surface of the central through hole 32 of the coil 3 and the outer peripheral surface of the long side post 13, which can bond the coil 3 pre-fitted on the long side post 13 and the long side post 13 formed by the contact of the first side post 12 and the second side post 22 into a whole.

[0052] Understandably, since the coil 3 is fitted onto the long side post 13 with a clearance fit through the central through hole 32, there is a possibility of relative displacement between the coil 3 and the long side post 13 in both the radial and axial directions. The adhesive layer, by impregnating and curing in the tiny gap between the coil 3 and the long side post 13, restricts the axial sliding and circumferential rotation of the coil 3 relative to the long side post 13, thus keeping the coil 3 in a constant posture.

[0053] In one embodiment, the adhesive layer is at least one of an epoxy resin adhesive layer, an organosilicon adhesive layer, an acrylic adhesive layer, and a polyurethane adhesive layer. Furthermore, the adhesive layer can be filled between the coil 3 and the long side post 13 by syringe dispensing, automatic spraying, brushing, or impregnation methods; no specific limitation is made here.

[0054] In one embodiment, the adhesive layer is only applied to local areas at both ends of the coil 3 to form positioning points, or it can be continuously applied along the axial direction of the long side post 13 to form a complete adhesive surface.

[0055] This invention also proposes a method for fabricating a common-mode inductor 100, the method comprising: S100, a first magnetic core 1 and a second magnetic core 2 are provided. The first magnetic core 1 has a first central post 11 and two first side posts 12 disposed on both sides of the first central post 11. The second magnetic core 2 has a second central post 21 and two second side posts 22 disposed on both sides of the second central post 21.

[0056] This step is the initial stage of the fabrication process, aiming to prepare two symmetrical and interlocking separate magnetic core components. The first magnetic core 1 and the second magnetic core 2 are in a separate state during the provision stage, with their respective side posts and center posts exposed to the outside, providing the operational conditions for the subsequent installation of the coil 3 and the closure of the magnetic cores.

[0057] S200 provides two coils 3.

[0058] This step aims to prepare two pre-wound electromagnetic induction components as the energy conversion core of the common-mode inductor 100. The coils 3 are pre-wound into a cylindrical structure with a central through-hole 32 using automated winding equipment. Their dimensions are adapted to the first side post 12 and the subsequently formed long side post 13, eliminating the need for on-site winding on the first magnetic core 1 and the second magnetic core 2. The number of turns, wire density, and tension of the two coils 3 are standardized and controlled during the supply stage, ensuring the consistency of the electrical parameters of the two coils 3 during subsequent assembly.

[0059] S300, the two coils 3 are respectively fitted onto the two first side posts 12.

[0060] This step involves installing the two pre-provided coils 3 onto the two first side posts 12 of the first magnetic core 1. Since the first magnetic core 1 is in an independent state at this time, the outer sides of the two first side posts 12 have open operating space. The coils 3 can be directly inserted into the first side posts 12 axially through their central through holes 32, without being obstructed by the second magnetic core 2 and the first central post 11 during the insertion process. The two coils 3 are respectively positioned on the first side posts 12 on both sides of the first magnetic core 1.

[0061] S400, the first magnetic core 1 and the second magnetic core 2 are closed relative to each other so that each first side post 12 abuts against a second side post 22 to form a long side post 13, and there is a gap between the first middle post 11 and the second middle post 21.

[0062] This step involves bringing together the first magnetic core 1 and the second magnetic core 2, with the coil 3 already fitted, along the mating direction. During the closing process, the two first side posts 12 of the first magnetic core 1 and the two second side posts 22 of the second magnetic core 2 are axially aligned. Then, the end faces of the first side posts 12 and the corresponding end faces of the second side posts 22 abut against each other, splicing together to form a long side post 13 extending axially. This allows the coil 3, previously fitted onto the first side posts 12, to naturally transition to a state fitted onto the long side posts 13. At the same time, the end faces of the first central post 11 and the second central post 21 are spaced after closing. This space forms an air gap inside the magnetic core, providing radial tightening space for subsequent winding operations and suppressing magnetic saturation under DC bias by increasing the magnetic circuit reluctance.

[0063] S500, fix the two coils 3 to the corresponding long side post 13 to complete the overall installation.

[0064] In one implementation, please refer to Figure 5 S400, the steps for relatively closing the first magnetic core 1 and the second magnetic core 2 include: S401, Align the two first side posts 12 with the two second side posts 22 respectively.

[0065] The two first side posts 12 of the first magnetic core 1 and the two second side posts 22 of the second magnetic core 2 are aligned axially and circumferentially so that the end face of the first side post 12 and the end face of the corresponding second side post 22 are in a coaxial and parallel abutment state to prevent misalignment during the closing process.

[0066] S401, the winding member is wrapped around the outer periphery of the first central post 11 and the second central post 21 so that the first side post 12 abuts against the corresponding second side post 22.

[0067] The winding member is wound around the corresponding area on the outer periphery of the first central column 11 and the second central column 21. Since there is a gap between the first central column 11 and the second central column 21, the winding member can cross the gap and apply opposing clamping forces to the first magnetic core 1 and the second magnetic core 2 when it is wound up. The clamping force generates a tensioning effect in the axial direction, thereby driving the first magnetic core 1 and the second magnetic core 2 to move closer to each other until the end face of the first side column 12 and the end face of the corresponding second side column 22 are tightly abutted, forming a continuous long side column 13.

[0068] In one embodiment, S500, the step of fixing the two coils 3 to the corresponding long side post 13 includes: S501, insert the pins 31 of the two coils 3 into the limiting grooves 41 of the fixture 4 so that the first magnetic core 1 and the second magnetic core 2 are suspended and supported on the fixture 4.

[0069] Insert the pins 31 of the two coils 3 into the limiting grooves 41 of the fixture 4. Since the pins 31 extend in a direction perpendicular to the axial direction of the long side post 13, and the free ends of the two pins 31 face the same side, after being inserted into the limiting grooves 41, the pins 31 cooperate with the groove wall of the limiting grooves 41, thereby suspending and supporting the entire assembly composed of the first magnetic core 1, the second magnetic core 2 and the two coils 3 above the fixture 4, so that the bottom surface and outer peripheral surface of the first magnetic core 1 and the second magnetic core 2 are detached from the surface of the fixture 4, forming a suspended state.

[0070] S502, the coil 3 is bonded to the corresponding long side post 13 using an adhesive layer.

[0071] By using an adhesive layer to fill the gap between the inner wall of the central through hole 32 of the coil 3 and the outer circumference of the long side post 13, the coil 3 is bonded and fixed to the corresponding long side post 13, thereby completing the positioning of the coil 3 and the magnetic core.

[0072] Understandably, by inserting the pin 31 of coil 3 into the limiting groove 41 of fixture 4, it is equivalent to using pin 31 as a support arm to suspend the entire common mode inductor 100 on fixture 4, so that the first magnetic core 1, the second magnetic core 2, and coil 3 do not contact the surface of fixture 4. With this configuration, when adhesive is subsequently injected between coil 3 and the long side post 13, the adhesive can evenly penetrate the gap from all directions, preventing the adhesive from being squeezed out or unevenly distributed due to the bottom surface adhering to the surface of fixture 4. At the same time, the suspended state prevents the adhesive layer from sticking to fixture 4 during the curing process, thus avoiding damage during demolding.

[0073] In one embodiment, S502, the step of bonding the coil 3 to the corresponding long side post 13 using an adhesive layer further includes: injecting adhesive between the coil 3 and the long side post 13 and curing the adhesive.

[0074] In the process of bonding the coil 3 to the corresponding long side post 13 using an adhesive layer, liquid adhesive is injected into the gap between the inner wall of the central through hole 32 of the coil 3 and the outer peripheral surface of the long side post 13, so that the adhesive fully wets and covers the outer surface of the long side post 13 and the inner surface of the coil 3. Subsequently, the liquid adhesive undergoes a curing reaction, changing from a liquid state to a solid state, thereby forming an adhesive layer with a certain structural strength, fixing the coil 3 to the predetermined position of the long side post 13.

[0075] The curing methods can include heat curing, ultraviolet (UV) irradiation curing, infrared (IR) irradiation curing, and natural room temperature curing. The heat curing temperature can be set from 80℃ to 150℃ depending on the type of adhesive, and the curing time can be from 10 minutes to 2 hours. For UV curing, a UV light source with a wavelength of 365nm or 405nm can be used, and the irradiation time can be from 5 seconds to 60 seconds.

[0076] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A common-mode inductor, characterized in that, The common-mode inductor includes: A first magnetic core, the first magnetic core having a first central post and two first side posts disposed on both sides of the first central post; The second magnetic core is separate from the first magnetic core. The second magnetic core has a second central post and two second side posts located on either side of the second central post. Each first side post abuts against one of the second side posts to form a long side post, and there is a gap between the first central post and the second central post. Two coils are respectively fitted onto the two long side posts.

2. The common-mode inductor as described in claim 1, characterized in that, Each of the coils has two pins that extend in a direction perpendicular to the axial direction of the long side post, and the free ends of the two pins face the same side.

3. The common-mode inductor as described in claim 2, characterized in that, The common mode inductor also includes a winding member, which is wound around the outer periphery of the first magnetic core and the second magnetic core and is disposed corresponding to the first central post and the second central post, for tightening and fixing the first magnetic core and the second magnetic core.

4. The common-mode inductor as described in claim 3, characterized in that, An adhesive layer is provided between each coil and the corresponding long side post for bonding the coil to the long side post.

5. A method for fabricating a common-mode inductor, characterized in that, The preparation method includes: A first magnetic core and a second magnetic core are provided. The first magnetic core has a first central post and two first side posts disposed on both sides of the first central post. The second magnetic core has a second central post and two second side posts disposed on both sides of the second central post. Two coils are provided; The two coils are respectively fitted onto the two first side posts; The first magnetic core and the second magnetic core are relatively closed, so that each of the first side posts abuts against a second side post to form a long side post, and there is a gap between the first middle post and the second middle post; and The two coils are fixed to the corresponding long side post.

6. The preparation method according to claim 5, characterized in that, The step of relatively closing the first magnetic core and the second magnetic core includes: Align the two first side posts with the two second side posts respectively; and The first and second center posts are wrapped with a winding material so that the first side post abuts against the corresponding second side post.

7. The preparation method according to claim 6, characterized in that, The winding component is tape, binding tape, sleeve, or clamp.

8. The preparation method according to claim 5, characterized in that, The step of fixing the two coils to the corresponding long side post includes: The pins of the two coils are inserted into the limiting slots of the fixture, so that the first magnetic core and the second magnetic core are suspended and supported by the fixture; and The coil is bonded to the corresponding long side post using an adhesive layer.

9. The preparation method according to claim 8, characterized in that, The step of bonding the coil to the corresponding long side post using an adhesive layer includes: injecting adhesive between the coil and the long side post, and curing the adhesive.

10. The preparation method according to claim 5, characterized in that, Each of the coils is a prefabricated cylindrical coil having a central through hole.

Images