Common mode inductor and electronic equipment
By using spaced coils and interleaved magnetic and non-magnetic sheets to form an air gap structure in the common-mode inductor, the problem of coil heating caused by magnetic line leakage is solved, achieving more efficient electromagnetic interference suppression and heat dissipation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-20
- Publication Date
- 2026-03-06
AI Technical Summary
Existing common-mode inductors suffer from severe leakage of magnetic field lines near the air gap, resulting in significant heat generation in the coil and affecting the operation of electronic equipment.
Design a common-mode inductor that uses spaced coils and air-gap components. The air-gap components are formed by alternating layers of magnetic and non-magnetic sheets to create multiple air-gap structures, thereby reducing the air-gap size to decrease magnetic line leakage and eddy current losses.
By reducing magnetic field leakage and eddy current losses, the heat generation of the coil is reduced, thus improving the performance of the common mode inductor.
Smart Images
Figure CN223977783U_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the technical field of inductors, and more specifically, relates to a common-mode inductor and electronic equipment. Background Technology
[0002] A common-mode inductor is an inductor used to suppress differential-mode and common-mode interference in electronic devices. It protects electronic devices from electromagnetic interference by providing a high-impedance path in the circuit to suppress high-frequency noise.
[0003] A common-mode inductor consists of a magnetic core and two coils mounted on the core. These two coils form a common-mode inductance. A perforated structure is also present between the two coils, creating an air gap. The leakage inductance at this air gap forms a differential-mode inductance. To generate sufficient differential-mode inductance, the perforated structure is designed to be relatively large. This results in significant leakage of magnetic flux lines near the air gap. The leaked magnetic flux lines create eddy currents in the coils on both sides, increasing eddy current losses and generating excessive heat, which can negatively impact the operation of electronic equipment. Utility Model Content
[0004] The purpose of this application is to provide a common-mode inductor and electronic device to solve the problem of severe leakage of magnetic lines of force near the air gap in the prior art, which leads to a large amount of heat generation in the coil.
[0005] To achieve the above objectives, in a first aspect, this application provides a common-mode inductor, including a base plate, a magnetic core disposed on the base plate, a coil wound on the magnetic core, and an air gap assembly disposed on the magnetic core; the number of coils is two and they are arranged at intervals along a first direction, the first direction being perpendicular to the axis of the coils; the air gap assembly is located between the two coils, and the air gap assembly has a plurality of air gap structures arranged at intervals along a second direction, the second direction being parallel to the axis of the coils.
[0006] In some embodiments of the first aspect, the air gap assembly includes at least one magnetic sheet and at least two non-magnetic sheets, wherein at least one magnetic sheet and at least two non-magnetic sheets are staggered and stacked along the second direction.
[0007] In some embodiments of the first aspect, the magnetic core includes two magnets and two magnetic pillars, the two magnets are spaced apart along the second direction, the two magnetic pillars are spaced apart between the two magnets along the first direction, and the two ends of the magnetic pillars are respectively connected to the corresponding magnets; two coils are respectively wound around the two magnetic pillars, the air gap assembly is located between the two magnetic pillars, and the two ends of the air gap assembly are respectively connected to the two magnets.
[0008] In some embodiments of the first aspect, the magnet has a protrusion on its end face facing the air gap assembly, and one end of the air gap assembly abuts against the end face of the protrusion facing away from the magnet.
[0009] In some embodiments of the first aspect, the magnetic column includes two columns, each of which is connected to one of the two magnets, and the opposite end faces of the two columns abut against each other.
[0010] In some embodiments of the first aspect, a pad is provided on the base plate, and the magnet is connected to the pad.
[0011] In some embodiments of the first aspect, the thickness of the non-magnetic sheet is greater than or equal to 0.6 mm.
[0012] In some embodiments of the first aspect, the non-magnetic sheet is a ceramic sheet or an epoxy resin sheet.
[0013] In some embodiments of the first aspect, both the input and output ends of the coil are provided with terminals.
[0014] In a second aspect, this application provides an electronic device including a common-mode inductor as described in the first aspect and any alternative embodiments thereof.
[0015] The beneficial effects of the common-mode inductor and electronic device provided in this application are as follows: two coils spaced apart on the magnetic core constitute a common-mode inductor; an air gap assembly disposed on the magnetic core forms multiple spaced air gap structures between the two coils; the leakage inductance generated by the common-mode inductor at the air gap structure forms a differential-mode inductor; under the action of multiple air gap structures, sufficient differential-mode inductance can be generated; at the same time, the size of each air gap structure is reduced to reduce the leakage of magnetic field lines at the air gap structure, reduce the generation of eddy currents on the coil, reduce the heat generated by the coil during operation, and improve the performance of the common-mode inductor. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of this application, 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a schematic diagram of the structure of a common mode inductor according to an exemplary embodiment of this application;
[0018] Figure 2 This is an exploded view of a common-mode inductor, an exemplary embodiment of this application.
[0019] Figure 3This is a partial cross-sectional view of a common mode inductor in an exemplary embodiment of this application;
[0020] Figure 4 This is an exploded view of the air gap assembly in an exemplary embodiment of this application.
[0021] The following are the labeling elements in the figure:
[0022] 10-Base plate; 11-Through hole;
[0023] 20 - Magnetic core; 21 - Magnet; 211 - Protrusion; 22 - Magnetic column; 22a - Column;
[0024] 30 - Coil; 31 - Terminal block; 311 - Connection hole;
[0025] 40 - Air gap assembly; 41 - Magnetic sheet; 42 - Non-magnetic sheet;
[0026] 50-Place block. Detailed Implementation
[0027] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.
[0028] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.
[0029] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application 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, they should not be construed as limitations on this application.
[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0031] This application provides a common-mode inductor, such as... Figures 1-4 As shown, the common-mode inductor includes a base plate 10, a magnetic core 20 disposed on the base plate 10, a coil 30 wound around the magnetic core 20, and an air gap assembly 40 disposed on the magnetic core 20. There are two coils 30 arranged at intervals along a first direction, which is perpendicular to the axis of the coils 30. The air gap assembly 40 is located between the two coils 30 and has multiple air gap structures arranged at intervals along a second direction, which is parallel to the axis of the coils 30.
[0032] Specifically, the base plate 10 is a flat plate structure with a certain area, whose function is to support the magnetic core 20 and ensure the stability of the entire common-mode inductor. For example... Figure 1 As shown, when used in a common-mode inductor, the base plate 10 can be horizontal, with the magnetic core 20, coil 30, and air gap assembly 40 all positioned on the upper side of the base plate 10. The base plate 10 can be rectangular or other geometric shapes, and it can be made of insulating material to prevent current leakage and short circuits. Optionally, the base plate 10 is an epoxy resin board.
[0033] The magnetic core 20 is a magnetically conductive structure made of manganese-zinc ferrite or other magnetically conductive materials. It provides a winding position for the two coils 30 and a mounting position for the air gap assembly 40, ensuring that the air gap assembly 40 is stably positioned between the two coils 30. The coils 30 are formed by winding conductive materials such as copper around the corresponding positions of the magnetic core 20. When the base plate 10 is in a horizontal position, the axis of the coils 30 can be parallel to the width direction of the base plate 10. The first direction can be the length direction of the base plate 10, meaning that the two coils 30 are not located on opposite sides of the length direction of the base plate 10.
[0034] Two coils 30 constitute a common-mode inductor, achieving common-mode rejection. The shape of the conductors constituting the coils 30, the number of turns, the wire diameter, and the winding method can all be designed according to the specific application requirements of the common-mode inductor. Optionally, the coils 30 can use rectangular flat conductors wound on the magnetic core 20 using a vertical winding process, so that there is sufficient gap between the turns of the coils 30, increasing the heat dissipation area of the coils 30 and improving heat dissipation performance.
[0035] The air gap assembly 40 can also be arranged along the width direction of the base plate 10. The air gap assembly 40 is mounted on the magnetic core 20 and located between the two magnetic cores 20. The multiple air gap structures on the air gap assembly 40 can be air gaps formed by hollow structures or gaps made of non-magnetic materials. The common-mode inductance formed by the two coils 30 will generate leakage inductance at the air gap structure. The leakage inductance is used as the differential-mode inductance to suppress differential-mode interference.
[0036] With the help of multiple air gap structures, sufficient differential mode inductance can be generated to meet product requirements while reducing the thickness of each air gap structure and reducing the leakage of magnetic field lines at the air gap structure. This reduces the generation of eddy currents on coil 30, resulting in less heat generation of coil 30 during operation and improving the performance of common mode inductor.
[0037] like Figure 2 and Figure 3 As shown, in some embodiments, the air gap assembly 40 includes at least one magnetic sheet 41 and at least two non-magnetic sheets 42, wherein the at least one magnetic sheet 41 and the at least two non-magnetic sheets 42 are staggered and stacked along a second direction.
[0038] The magnetic sheet 41 is a flat plate structure made of magnetically conductive material, and its shape can be rectangular or other geometric shapes. The non-magnetic sheet 42 is made of non-magnetically conductive material, and its shape can be the same as or different from that of the magnetic sheet 41. The magnetic sheets 41 and non-magnetic sheets 42 are stacked alternately, and adjacent magnetic sheets 41 and non-magnetic sheets 42 can be fixed together with adhesive. Optionally, the material of the magnetic sheet 41 is the same as that of the magnetic core 20 to ensure the continuity of the magnetic circuit and the effective transmission of magnetic flux. Optionally, the non-magnetic sheet 42 is a ceramic sheet or an epoxy resin sheet.
[0039] The number of non-magnetic sheets 42 should exceed the number of magnetic sheets 41, so that each magnetic sheet 41 has non-magnetic sheets 42 stacked on both sides. For example, Figure 2 and Figure 3 As shown, the air gap assembly 40 includes three magnetic sheets 41 and four non-magnetic sheets 42, which are stacked sequentially. The sheets at both ends of the air gap assembly 40 are non-magnetic sheets 42. When connecting the air gap assembly 40 to the magnetic core 20, adhesive can be used to bond and fix the non-magnetic sheets 42 to their corresponding positions on the magnetic core 20. Multiple non-magnetic sheets 42 separate multiple magnetic sheets 41 and the magnetic core 20. Since the permeability μ of the non-magnetic sheets 42 is approximately equal to the permeability μ0 of air, each non-magnetic sheet 42 can serve as an air gap structure.
[0040] In some embodiments, the thickness of the non-magnetic sheet 42 is greater than or equal to 0.6 mm. Specifically, the thickness of each non-magnetic sheet 42 can be determined based on the total length of the air gap structure required in the air gap assembly 40 and the number of non-magnetic sheets 42. The thickness of each non-magnetic sheet 42 can be the same or different. The non-magnetic sheets 42 form a small air gap structure to effectively close magnetic lines of force, confining most of the magnetic lines of force within the smaller air gap structure, reducing leakage and eddy current losses. The thickness of the non-magnetic sheet 42 is kept to a minimum of 0.6 mm to avoid adjacent magnetic sheets 41 being too close together, ensuring the effectiveness of the air gap structure.
[0041] In some embodiments, the magnetic core 20 includes two magnets 21 and two magnetic pillars 22. The two magnets 21 are arranged at intervals along a second direction, and the two magnetic pillars 22 are arranged at intervals between the two magnets 21 along a first direction. The two ends of the magnetic pillars 22 are respectively connected to the corresponding magnets 21. Two coils 30 are respectively wound around the two magnetic pillars 22. An air gap assembly 40 is located between the two magnetic pillars 22, and the two ends of the air gap assembly 40 are respectively connected to the two magnets 21.
[0042] The magnet 21 is a plate-shaped magnet with a certain area. When the base plate 10 is in a horizontal position, the magnet 21 can be in a vertical position. The two magnets 21 are parallel to each other and arranged at intervals, so that there is space between the two magnets 21 to install the magnetic column 22, the coil 30 and the air gap assembly 40.
[0043] The magnetic post 22 is arranged between the two magnets 21 along the width direction of the base plate 10. The cross-sectional shape of the magnetic post 22 can be circular or other geometric shapes, and it is used to provide a winding position for the coil 30. After the coil 30 is wound on the magnetic post 22, the two magnets 21 are located on both sides of the axial direction of the coil 30, which can limit the axial position of the coil 30, prevent the coil 30 from detaching from the magnetic post 22 during use, and ensure the stability of the structure.
[0044] In some embodiments, the end face of the magnet 21 facing the air gap assembly 40 is provided with a protrusion 211, the protrusion 211 is located between two magnetic pillars 22, and the end of the air gap assembly 40 abuts against the end face of the protrusion 211 facing away from the magnet 21.
[0045] The shape of the protrusion 211 can be the same as the end face shape of the air gap assembly 40. For example, the protrusion 211 can be the same as the shape of the non-magnetic sheet 42. The protrusions 211 on the two magnets 21 are positioned corresponding to each other, forming a mounting cavity between the two protrusions 211 with a length matching the length of the air gap assembly 40. When installing the air gap assembly 40, glue can be used to bond the non-magnetic sheet 42 located on the end side of the air gap assembly 40 to the end face of the corresponding protrusion 211, clamping the entire air gap assembly 40 between the two protrusions 211, so that the air gap assembly 40 is positioned between the two coils 30, ensuring the stable position of the air gap assembly 40 in the magnetic core 20.
[0046] In some embodiments, the magnetic column 22 includes two columns 22a, which are respectively connected to two magnets 21, and the opposite end faces of the two columns 22a abut against each other.
[0047] like Figure 2 and Figure 4As shown, each magnetic pillar 22 is composed of two coaxially arranged pillars 22a. The pillars 22a can be integrally formed with the corresponding magnets 21 on one side, so that the entire magnetic core 20 is composed of two mirror-symmetrical parts. This facilitates the mounting of the coil 30 on the magnetic pillar 22 and also facilitates the connection between the air gap assembly 40 and the protrusion 211, reducing the assembly difficulty of the common-mode inductor. After assembly, the stability of the entire magnetic core 20 structure can be maintained by connecting the air gap structure to the magnets 21 on both sides or by connecting the magnets 21 to the base plate 10, ensuring that the end faces of the corresponding two pillars 22a fit tightly together.
[0048] In some embodiments, a pad 50 is provided on the base plate 10, and the magnetic core 20 is connected to the pad 50.
[0049] Specifically, the pad 50 is a support structure with a certain volume. The pad 50 can be a rectangular block structure or other block structures, used to support the magnetic core 20 on the base plate 10. The pad 50 can be made of insulating material to prevent current leakage and short circuits. Optionally, the pad 50 is an epoxy resin block.
[0050] The number of spacers 50 can be the same as the number of magnets 21 in the magnetic core 20. Two magnets 21 correspond one-to-one with two spacers 50. The bottom of the magnet 21 is fixed to the corresponding spacer 50, so that the magnetic core 20 is supported above the base plate 10 by the spacers 50, so that there is a gap between each coil 30 and the base plate 10, increasing the heat dissipation space. The magnets 21 and the spacers 50 can be connected and fixed by adhesive or other means.
[0051] In some embodiments, both the input and output ends of the coil 30 are provided with terminals 31.
[0052] Specifically, the input and output wires of the coil 30 can be extended outward to form terminals 31. The base plate 10 can be provided with through holes 11 corresponding to each terminal 31. The terminals 31 extend through the corresponding through holes 11 to the bottom of the base plate 10. Each terminal 31 can be provided with a connection hole 311 to facilitate the connection between the coil 30 and the external circuit.
[0053] In summary, the common-mode inductor provided in this application embodiment can form a differential-mode inductor between two coils 30 through multiple spaced air gap structures on the air gap assembly 40. The multiple air gap structures can ensure sufficient differential-mode inductance and reduce the size of each air gap structure, which has a good effect of closing magnetic lines of force, reducing the leakage of magnetic lines of force at the air gap structure, thereby reducing the generation of eddy currents on the coil 30, making the heat generated by the coil 30 during operation less, and improving the performance of the common-mode inductor.
[0054] Secondly, embodiments of this application also provide an electronic device, including a common-mode inductor as described in the first aspect embodiment.
[0055] The electronic devices can be computers, mobile communication devices, multimedia players, video game consoles, home theater systems, and various industrial automation equipment. Common-mode inductors can be connected to the circuit board of the electronic device via the coil's terminals to connect the common-mode inductor to the EMC (Electromagnetic Compatibility) circuit. This reduces electromagnetic interference, improves the anti-interference capability of the electronic device, and ensures its stable operation.
[0056] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A common mode inductor, characterized by The common mode inductor comprises a bottom plate, a magnetic core arranged on the bottom plate, a coil wound on the magnetic core, and an air gap assembly arranged on the magnetic core; the number of the coils is two and the coils are arranged in a first direction perpendicular to the axis of the coils; the air gap assembly is located between the two coils, and the air gap assembly has a plurality of air gap structures arranged in a second direction parallel to the axis of the coils.
2. The common mode inductor of claim 1, wherein, The air gap assembly comprises at least one magnetic conducting sheet and at least two non-magnetic conducting sheets, and the at least one magnetic conducting sheet and the at least two non-magnetic conducting sheets are arranged in a staggered manner in the second direction.
3. The common mode inductor of claim 1, wherein, The magnetic core comprises two magnets and two magnetic columns, the two magnets are arranged in the second direction, the two magnetic columns are arranged in the first direction between the two magnets, and the two ends of the magnetic columns are connected to the corresponding magnets, respectively; the two coils are wound on the two magnetic columns, respectively, the air gap assembly is located between the two magnetic columns, and the two ends of the air gap assembly are connected to the two magnets, respectively.
4. The common mode inductor of claim 3, wherein, The end surface of the magnet facing the air gap assembly is provided with a protruding portion, the protruding portion is located between the two magnetic columns, and the end of the air gap assembly abuts against the end surface of the protruding portion away from the magnet.
5. The common mode inductor of claim 3, wherein, The magnetic column comprises two column bodies, the two column bodies are connected to the two magnets, respectively, and the opposite end surfaces of the two column bodies abut against each other.
6. The common mode inductor of claim 1, wherein, The bottom plate is provided with a pad, and the magnetic core is connected to the pad.
7. The common mode inductor of claim 2, wherein, The thickness of the non-magnetic conducting sheet is greater than or equal to 0.6 mm.
8. The common mode inductor of claim 2, wherein, The non-magnetic conducting sheet is a ceramic sheet or an epoxy resin sheet.
9. The common mode inductor of any of claims 1-8, wherein, The input end and the output end of the coil are provided with a terminal.
10. An electronic device, comprising: The common mode inductor comprises a bottom plate, a magnetic core arranged on the bottom plate, a coil wound on the magnetic core, and an air gap assembly arranged on the magnetic core; the number of the coils is two and the coils are arranged in a first direction perpendicular to the axis of the coils; the air gap assembly is located between the two coils, and the air gap assembly has a plurality of air gap structures arranged in a second direction parallel to the axis of the coils.