Common mode inductor
By integrally injection molding the protective shell on the outer circumference of the common-mode inductive core, the problem of difficulty in reaching safety of manganese zinc high-permeability core is solved, and the effect of simplifying production, reducing costs and improving insulation protection is achieved.
Patent Information
- Application Number
- CN202422274072.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-14
- Publication Date
- 2025-07-25
- Estimated Expiration
- 2034-09-14
AI Technical Summary
The existing manganese zinc high-permeable cores with common mode inductors are difficult to meet safety requirements through coating, resulting in complex and high cost. The traditional tape wrapping and assembly methods of shells are not beautiful and increase costs.
The protective shell is integrally injection molded on the outer circumference of the magnetic core, and two strands of windings are wound on the outer circumference of the protective shell. The protective shell is made of baicalenne, PBT or PET material, and notches are provided for fixing the winding ends, meeting safety regulations and simplifying production.
It has achieved simplification of production processes, reduced material costs, improved insulation protection effect, met safety regulations, and made the appearance easier to control.
Smart Images
Figure CN223155777U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of electronic components, in particular to a common-mode inductor. Background Art
[0002] Common-mode inductors can achieve very large common-mode inductance values on magnetic cores with very small structures and are widely used in EMI filters. It plays a very important role in suppressing conducted EMI noise. Common-mode inductors are widely used in the common-mode interference suppression of the input L and N lines of switching power supplies and high-speed differential signals.
[0003] Common-mode inductors usually consist of the following main components: Copper wire: The surface of the internal conductor is coated with an insulating layer. The coil winding is the core of the inductor, which is evenly wound by a wire on a magnetic ring covered with a protective shell. The number of turns of the coil and the shape and distance of the winding will affect the performance of the inductor component. Magnetic materials: Commonly used ones include ferrites, powder core alloys, nanocrystalline amorphous materials, etc., which are mainly used to increase the inductance of the inductor and improve the efficiency of the inductor. Magnetic materials are usually located inside the coil to form a closed magnetic field loop, concentrate the magnetic field and increase the inductance value of the inductor. Insulating materials: Bottom substrates, isolation baffles between windings, insulating sleeves, etc. Common insulating materials include plastics, FR4 boards, papers, fiberglass, etc.
[0004] The inductance value of common-mode inductors is generally relatively large because the magnetic fluxes flowing through the magnetic ring are superimposed on each other, which plays an inhibitory role on the common-mode current. Considering the product size and inductance value requirements, generally, nanocrystals and manganese-zinc high-permeability ferrites are selected for the magnetic cores of common-mode inductors. Nanocrystals are much higher in cost than manganese-zinc high-permeability ferrites, but the number of coil turns will be greatly reduced, directly reducing the product size. Therefore, for some common-mode inductors, considering the product size and cost, we prefer to choose manganese-zinc high-permeability ferrites. However, when there are safety regulations requirements from customers, the coated manganese-zinc high-permeability ferrites cannot meet the safety regulations EIS requirements because according to the UL insulation system requirements, the coating is not on the EIS list. Currently, the general practice in the market is to wrap tape around the magnetic core or use an assembled housing to meet the safety regulations requirements. Both of these processes are very complex and costly. Wrapping tape around the magnetic core requires a tape wrapping machine and the appearance is not beautiful. Assembling the housing requires opening male and female molds and subsequent manual assembly. These will increase greater costs and cumbersome processes. Moreover, wrapping tape not only increases cost investment and the process is cumbersome, but also faces the adverse effects of uneven tape wrapping on the winding process. Therefore, it is very necessary to design a high-permeability ferrite common-mode inductor with simple process operation and meeting safety regulations requirements. Summary of the Utility Model
[0005] The purpose of the utility model is to solve the problem of the deficiency that the manganese-zinc high-permeability magnetic core for preparing common-mode inductors in the prior art cannot meet the safety regulations requirements through coating, and to propose a common-mode inductor.
[0006] To achieve the above object, the utility model adopts the following technical solutions:
[0007] A common mode inductor includes a magnetic core and two strands of winding wires. The common mode inductor further includes a protective shell. The protective shell has a cavity capable of completely accommodating the magnetic core, and the shape of the protective shell is the same as that of the magnetic core. The magnetic core is located inside the cavity. The protective shell is integrally injection-molded on the outer peripheral side of the magnetic core, and the two strands of winding wires are respectively wound around the outer peripheral side of the protective shell.
[0008] The protective shell includes a substrate integrally injection-molded on its outer peripheral side.
[0009] The substrate is provided with a plurality of notches.
[0010] The number of the notches is four, and the four notches are distributed in pairs on both sides of the magnetic core.
[0011] The notch is a C-shaped notch.
[0012] The length range of the substrate is 24 mm - 28 mm, the width range is 20 mm - 24 mm, and the thickness range is 1.5 mm - 3 mm.
[0013] The starting end and the ending end of the winding wire are respectively limited in the notches.
[0014] The common mode inductor includes a fixing member, and both the starting end and the ending end of the winding wire are fixed in the notches through the fixing member.
[0015] The fixing member is glue dropped between the notch and the winding wire.
[0016] The protective shell is injection-molded from bakelite, PBT or PET;
[0017] and / or the magnetic core is a high-permeability manganese-zinc ferrite magnetic core;
[0018] and / or the winding wire is one of copper wire, aluminum wire, gold wire, and silver wire with an insulating layer;
[0019] and / or the protective shell includes baffle portions integrally injection-molded on both sides thereof.
[0020] For a common mode inductor proposed by the utility model, the beneficial effects are as follows: The device directly injection-molds a protective shell with a shape matching that of the magnetic core on the outer peripheral side of the magnetic core. Compared with the traditional method of winding with tape, the production of this device is simpler, and it is easier to control the appearance of the protective shell, and the quality is easier to control. It can form better insulation protection through the injection-molded protective shell and better meet the safety regulations requirements. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 It is a schematic diagram of the overall three-dimensional structure of the utility model;
[0022] Figure 2 is a schematic cross-sectional structure diagram of the present utility model;
[0023] Figure 3 is a schematic three-dimensional structure diagram of the protective shell of the present utility model;
[0024] Figure 4 is a schematic semi-sectional structure diagram of the protective shell of the present utility model.
[0025] In the figure: protective shell 1, winding 2, substrate 3, fixing member 4, notch 5, baffle portion 6, magnetic core 7, cavity 8. Specific embodiments
[0026] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments.
[0027] Referring to Figures 1-4 , a common mode inductor includes a magnetic core 7 and two windings 2. The common mode inductor further includes a protective shell 1. The protective shell 1 has a cavity 8 that can completely accommodate the magnetic core 7, and the shape of the protective shell 1 is the same as the shape of the magnetic core 7. The protective shell 1 completely wraps the magnetic core 7, that is, the shape of the cavity 8 matches the shape of the magnetic core 7. For example, if the magnetic core 7 adopts an annular structure, the cavity is also an annular cavity and the protective shell 1 is also an annular shell. If the shape of the internal magnetic core is rectangular, square or racetrack-shaped, then the shapes of the protective shell 1 and the cavity 8 will be adjusted accordingly. The magnetic core 7 is located inside the cavity 8. The protective shell 1 is integrally injection-molded on the outer peripheral side of the magnetic core 7, and the two windings 2 are respectively wound around the outer peripheral side of the protective shell 1.
[0028] The two windings 2 mentioned in the text refer to: it can be one strand per single wire, or two or more wires in parallel as one strand. For example, each strand uses two copper wires in parallel, and the number of wires in each strand is determined according to the working condition current density.
[0029] In this device, a protective shell 1 with a shape matching its own is directly injection-molded on the outer peripheral side of the magnetic core 7. Compared with the traditional method of winding with tape, the production of this device is simpler, and it is easier to control the appearance of the protective shell 1, and the quality is easier to control. The injection-molded protective shell 1 can form better insulation protection and better meet the safety regulations requirements.
[0030] As an implementation method, the thickness of the protective shell 1 is 1 mm - 1.5 mm, for example, 1.2 mm.
[0031] As an implementation manner, the protective shell 1 includes a substrate 3 integrally injection-molded on its outer peripheral side. The protective shell is integrally formed with the substrate. Through the arrangement of the substrate, it can be assembled more stably on the circuit board or the required circuit.
[0032] The substrate 3 is provided with a plurality of notches 5. The notches 5 are provided to facilitate the fixation of the starting end and the ending end of the winding 2.
[0033] As an implementation manner, the number of the notches 5 is four, and the four notches 5 are distributed in pairs on both sides of the magnetic core 7. When the winding 2 has two strands, the starting end and the ending end of each strand of winding respectively correspond to one notch, so as to avoid the contact between the two ends of the winding 2 and between adjacent windings.
[0034] As an implementation manner, referring to Figure 1 、 Figure 3 , the protective shell with the substrate of the present device is integrally injection-molded on the outer peripheral side of the magnetic core, and the winding 2 is wound on the protective shell 1 later. Therefore, it is relatively difficult to insert the two ends of the winding into the notches up and down during winding. The notch 5 of the present device is a C-shaped notch, that is, the outside of the notch 5 is open. In this way, the winding can be inserted into the substrate from the open side of the notch 5, which reduces the assembly difficulty between the two ends of the winding and the substrate.
[0035] As an implementation manner, the size of the open outside of the notch 5 is slightly smaller than the diameter of the winding. For example, the size of the open outside of the notch 5 is 90% of the diameter of the winding, so that it can be better inserted into the notch and the clamping is more stable.
[0036] As an implementation manner, the length range of the substrate 3 is: 24 mm - 28 mm, the width range is: 20 mm - 24 mm, and the thickness range is: 1.5 mm - 3 mm. For example, the length of the substrate 3 is: 26 mm, the width is: 22.5 mm, and the thickness is: 2 mm.
[0037] The starting end and the ending end of the winding 2 are respectively limited in the notch 5.
[0038] The common mode inductor includes a fixing member 4. The starting end and the ending end of the winding 2 are both fixed in the notch 5 through the fixing member 4, and the two ends of the winding 2 are stably connected to the substrate through the fixing member 4.
[0039] The fixing member 4 is glue dropped between the notch 5 and the winding 2. Due to the design of the card slot on the substrate of the present device, the amount of glue used is reduced by 90% compared with that of the traditional common mode inductor, which greatly reduces the raw material cost.
[0040] The protective shell 1 is injection-molded from bakelite, PBT or PET;
[0041] and / or the magnetic core 7 is a high-permeability manganese-zinc ferrite magnetic core;
[0042] and / or the winding 2 is one of copper wire, aluminum wire, gold wire, and silver wire with an insulating layer;
[0043] The protective case 1 includes baffle portions 6 integrally injection-molded on both sides thereof, avoiding additional installation of baffles or fasteners.
[0044] As described above, only the preferred specific embodiments of the present utility model are provided, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model, according to the technical solution and the inventive concept of the present utility model, makes equivalent substitutions or changes to obtain technical solutions, concepts, and designs, which should all be covered within the protection scope of the present utility model.
Claims
1. A common-mode inductor, comprising a magnetic core (7) and two strands of winding (2), characterized in that, The common mode inductor further includes a protective case (1), the protective case (1) has a cavity (8) capable of completely accommodating the magnetic core (7), and the shape of the protective case (1) is the same as that of the magnetic core (7). The magnetic core (7) is located in the cavity (8), the protective case (1) is integrally injection molded on the outer peripheral side of the magnetic core (7), and the two strands of winding wires (2) are respectively wound around the outer peripheral side of the protective case (1).
2. The common mode inductor according to claim 1, characterized in that, The protective case (1) includes a substrate (3) integrally injection molded on its outer peripheral side.
3. The common mode inductor according to claim 2, wherein, The substrate (3) is provided with a plurality of notches (5).
4. A common mode inductor according to claim 3, wherein The number of the notches (5) is four, and the four notches (5) are distributed in pairs on both sides of the magnetic core (7).
5. A common-mode inductor according to claim 3 or 4, characterized in that, The notch (5) is a C-shaped notch.
6. The common mode inductor according to claim 5, wherein, The length range of the substrate (3) is 24 mm - 28 mm, the width range is 20 mm - 24 mm, and the thickness range is 1.5 mm - 3 mm.
7. A common-mode inductor according to any one of claims 3, 4, and 6, characterized in that The starting end and the ending end of the winding wire (2) are respectively limited in the notch (5).
8. A common mode inductor according to claim 7, characterized in that, The common mode inductor includes a fixing member (4), and both the starting end and the ending end of the winding wire (2) are fixed in the notch (5) through the fixing member (4).
9. The common-mode inductor according to claim 8, wherein, The fixing member (4) is glue dropped between the notch (5) and the winding wire (2).
10. A common mode inductor according to any one of claims 2, 3, 4, 6, 8, and 9, characterized in that, The protective case (1) is injection molded from bakelite, PBT or PET; and / or the magnetic core (7) is a high-permeability manganese zinc ferrite magnetic core; and / or the winding wire (2) is one of copper wire, aluminum wire, gold wire, and silver wire with an insulating layer; and / or the protective case (1) includes baffle portions (6) integrally injection molded on both sides thereof.