Magnetic device capable of preventing magnetic core from cracking

Abstract

The invention discloses a magnetic device capable of preventing magnetic cores from cracking, which relates to the technical field of magnetic devices and comprises an insulating framework, a coil and two opposite magnetic cores. Each magnetic core comprises a U-shaped main body and a middle column, the U-shaped main body comprises a bottom edge and two side columns, one end of the bottom edge is fixedly connected with one end of one side column, the other end of the bottom edge is fixedly connected with one end of the other side column, one end of the middle column is fixedly connected with the middle part of the middle column, and the middle column and the two side columns are positioned on the same side of the bottom edge; the thickness of the bottom edge is larger than or equal to 1.3 times that of the side column, the thickness direction of the middle column is parallel to the width direction of the side column, and the thickness of the middle column is smaller than or equal to the width of the side column. A through hole is formed in the insulating framework, the middle column of one magnetic core is inserted into the through hole from one end of the through hole, the middle column of the other magnetic core is inserted into the through hole from the other end of the through hole, and the two magnetic cores are bonded. And the possibility that the transformer is thoroughly damaged due to the cracking of the magnetic core is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of magnetic devices, and in particular to a magnetic device capable of preventing a magnetic core from cracking. Background Art

[0002] For magnetic devices such as transformers and inductors, certain overall mechanical strength, insulation strength and moisture resistance are required. The industry uses the impregnation process to cover the product with insulating paint after immersion and vacuuming, and then heat and cure to achieve the purpose of improving mechanical strength, insulation and moisture resistance. The magnetic core plays an indispensable role in magnetic devices. It is a sintered magnetic metal oxide composed of an iron oxide mixture. It plays a vital role in power conversion, signal transmission and electromagnetic compatibility of magnetic devices.

[0003] During the impregnation process of traditional magnetic devices, adhesion will occur between the insulating varnish, magnetic core, skeleton and coil. When the impregnated product undergoes thermal expansion and contraction due to the influence of the ambient temperature, the thermal expansion coefficient of the insulating varnish is very different from that of the magnetic core, skeleton and coil, which will generate strong stress concentration on the body of the magnetic core, especially at the bottom of the magnetic core. When the stress exceeds the range that the magnetic core can withstand, it will cause the magnetic core to crack.

[0004] Core cracking reduces the mechanical strength of the core and the load-bearing capacity of the transformer. Once additional mechanical shock or vibration occurs, the transformer may be completely damaged. Core cracking will change the magnetic circuit of the transformer, thereby affecting the distribution of magnetic flux density and reducing the electrical performance of the transformer, such as increasing leakage, power imbalance, and harmonic content. The presence of core cracks will also make the appearance of the transformer uneven, causing appearance defects, affecting the reliability of the transformer's appearance, and seriously affecting the service life of the transformer. Summary of the invention

[0005] The object of the present invention is to provide a magnetic device that prevents the magnetic core from cracking, so as to solve the problems existing in the above-mentioned prior art and prevent the magnetic core of the magnetic device from cracking, so as to ensure the mechanical strength of the magnetic core.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a magnetic device for preventing a magnetic core from cracking, comprising an insulating skeleton, a coil and two magnetic cores arranged opposite to each other; each of the magnetic cores comprises a U-shaped body and a middle column, the U-shaped body comprises a bottom edge and two side columns, one end of the bottom edge is fixedly connected to one end of one of the side columns, the other end of the bottom edge is fixedly connected to one end of another of the side columns, one end of the middle column is fixedly connected to the middle of the middle column, and the middle column and the two side columns are located on the same side of the bottom edge; the thickness of the bottom edge is greater than or equal to 1.3 times the thickness of the side columns, the thickness direction of the middle column is parallel to the width direction of the side columns, and the thickness of the middle column is less than or equal to the width of the side columns;

[0008] A through hole is provided on the insulating skeleton, a middle column of one of the magnetic cores is inserted into the through hole from one end of the through hole, a middle column of another of the magnetic cores is inserted into the through hole from the other end of the through hole, and the middle columns of the two magnetic cores are bonded, a side column of one of the magnetic cores is bonded to a side column of the other magnetic core, and another side column of one of the magnetic cores is bonded to another side column of the other magnetic core.

[0009] Preferably, each of the magnetic cores is integrally formed.

[0010] Preferably, the middle columns of the two magnetic cores are bonded by adhesive, one side column of one magnetic core is bonded to one side column of the other magnetic core by adhesive, and another side column of one magnetic core is bonded to another side column of the other magnetic core by adhesive.

[0011] Preferably, the shape of the bottom edge is a regular cuboid.

[0012] Preferably, the entire magnetic device needs to be impregnated.

[0013] Preferably, the insulating varnish used in the impregnation treatment is a self-drying insulating varnish or a baking insulating varnish.

[0014] Preferably, the material of the magnetic core is Mn-Zn ferrite or Ni-Zn ferrite.

[0015] Preferably, the cross-sectional shape of the middle column and the side column of the magnetic core is rectangular or circular.

[0016] Preferably, the insulating frame is made of plastic.

[0017] Preferably, multiple layers of coils are wound around the portion of the insulating frame where the through holes are located, and insulating tapes are wound between two adjacent layers of coils and around all the coils as a whole.

[0018] Compared with the prior art, the present invention has achieved the following technical effects:

[0019] In the magnetic device for preventing the core from cracking of the present invention, each core includes a U-shaped body and a middle column of a specific structure, and the thickness of the bottom edge is greater than or equal to 1.3 times the thickness of the side column. This design enables the core to have better stability and strength distribution in the overall structure. When faced with stress caused by thermal expansion and contraction after impregnation, the stress can be dispersed more effectively to avoid stress concentration in the weak parts of the core, especially the bottom edge, thereby greatly reducing the risk of core cracking, ensuring the mechanical strength of the core, and then maintaining the carrying capacity of magnetic devices such as transformers, making them more reliable during long-term use, and reducing the possibility of complete damage to the transformer due to core cracking.

[0020] Furthermore, the thickness direction of the middle column is parallel to the width direction of the side column, and the thickness of the middle column is less than or equal to the width of the side column. Such a structural layout optimizes the stress distribution inside the magnetic core, further enhances the ability of the magnetic core to resist external stress, and enables the magnetic core to better maintain its own integrity in a complex working environment and impregnation process, thereby improving the stability and reliability of the magnetic device, ensuring its normal working performance, reducing the change in magnetic flux density distribution caused by deformation or cracking of the magnetic core structure, and reducing the adverse effects on the electrical performance of the transformer, such as reducing leakage, maintaining power balance, and reducing harmonic content.

[0021] Furthermore, each magnetic core is integrally formed, reducing the connection gaps and structural weaknesses inside the magnetic core. During the impregnation process and subsequent use, the integrally formed magnetic core can better resist the stress caused by the difference in thermal expansion coefficients between the insulating paint, magnetic core, skeleton and coil, avoiding the problem of overall cracking of the magnetic core caused by loose or cracked connection parts, improving the overall strength and stability of the magnetic core, ensuring the long-term stable operation of the magnetic device, and at the same time helping to maintain the neatness of the transformer appearance, reducing appearance defects, improving the appearance reliability of the transformer, and extending the service life of the transformer.

[0022] Furthermore, the middle columns of the two magnetic cores are bonded by adhesive, and the side columns are also bonded to each other by adhesive. This bonding method forms a tight overall structure between the two magnetic cores. After the impregnation treatment, when the product expands and contracts due to changes in ambient temperature, the adhesive can buffer the stress generated by the different thermal expansion coefficients between the magnetic cores and between the magnetic cores and other components to a certain extent, preventing excessive stress concentration on the magnetic core body, thereby effectively reducing the possibility of cracking of the magnetic core, ensuring the integrity and mechanical properties of the magnetic core, and then ensuring the normal operation of the magnetic device, improving its electrical performance and reliability, and reducing various performance degradation problems caused by cracking of the magnetic core, such as abnormal magnetic flux density distribution, increased leakage, etc., and also helping to maintain the appearance quality of the transformer and extend its service life.

[0023] Furthermore, the shape of the bottom edge is a regular rectangular parallelepiped, and this shape design enables the magnetic core to disperse stress more evenly when subjected to force, avoiding stress concentration in weak parts such as corners. During the impregnation process, when subjected to stress caused by thermal expansion and contraction of the insulating paint, the regular rectangular bottom edge can better withstand and transmit stress, reducing the cracking of the bottom edge of the magnetic core caused by stress concentration, thereby ensuring the mechanical strength of the magnetic core, maintaining the normal working state of the magnetic device, improving its stability and reliability, reducing the adverse effects of core cracking on the electrical performance and appearance quality of the transformer, and extending the service life of the transformer.

[0024] Furthermore, the magnetic device is impregnated as a whole, and a self-drying insulating varnish or a drying insulating varnish is used, which can improve the mechanical strength, insulating performance and moisture resistance of the magnetic device. Although the impregnation process may generate stress due to the difference in thermal expansion coefficients between the insulating varnish and the magnetic core and other components, this problem is effectively overcome through measures such as the magnetic core structure design and bonding method of the present invention, so that the magnetic device can obtain the advantages brought by the impregnation treatment while avoiding the risk of cracking of the magnetic core, ensuring the stability and reliability of the magnetic device in various working environments, improving its electrical performance and service life, so that it can better meet the strict requirements of magnetic devices such as transformers and inductors in power conversion, signal transmission and electromagnetic compatibility.

[0025] Furthermore, the material of the magnetic core is Mn-Zn ferrite or Ni-Zn ferrite, both of which have good magnetic properties and can meet the performance requirements of magnetic devices in terms of electromagnetic conversion, etc. At the same time, combined with the structural design of the present invention to avoid cracking of the magnetic core, the magnetic core can better resist stress caused by various factors on the basis of ensuring good magnetic properties, reduce the possibility of cracking of the magnetic core, improve the overall performance and reliability of the magnetic device, ensure that it can work stably during long-term use, maintain its electrical and mechanical properties, extend the service life of the magnetic device, and provide a strong guarantee for the efficient operation of equipment such as transformers.

[0026] Furthermore, the cross-sectional shape of the center column and the side column of the magnetic core is rectangular or circular. This cross-sectional shape design optimizes the structural strength of the magnetic core while ensuring the magnetic properties of the magnetic core. The rectangular cross-section can better adapt to the layout and stress conditions of the magnetic core in the magnetic device, and the circular cross-section has better stress distribution uniformity. Both cross-sectional shapes help the magnetic core resist the stress caused by factors such as thermal expansion and contraction, mechanical vibration, etc. during the impregnation process and daily work, reduce the risk of core cracking, and ensure the mechanical strength and integrity of the magnetic core, thereby maintaining the normal working performance of the magnetic device, improving its reliability and stability, extending the service life of the magnetic device, and reducing the maintenance and replacement costs caused by core cracking.

[0027] Furthermore, the material of the insulating skeleton is plastic, which has good insulation performance and certain flexibility. During the operation of the magnetic device, it can effectively isolate the coil and the magnetic core and other components to prevent the occurrence of electrical faults such as short circuits. At the same time, the flexibility of the plastic can buffer the stress caused by thermal expansion and contraction or mechanical vibration to a certain extent, reduce the adverse effects on the magnetic core, and cooperate with the magnetic core structure design and other measures of the present invention to further reduce the possibility of cracking of the magnetic core, improve the overall safety and reliability of the magnetic device, ensure its long-term stable operation, improve its electrical performance and service life, and provide strong support for the reliable application of magnetic devices in various complex environments.

[0028] Furthermore, multiple layers of coils are wound around the locations of the through holes on the insulating skeleton, and insulating tapes are wound between two adjacent layers of coils and around all the coils as a whole. This coil winding method not only ensures the insulation performance of the coils, prevents short circuits and leakage between coils, but also protects the magnetic core to a certain extent. The insulating tape can buffer the stress of the coils caused by factors such as current changes and temperature changes, reduce the impact on the magnetic core, and, in conjunction with the magnetic core structure design of the present invention and other protective measures, reduce the risk of cracking of the magnetic core, ensure the mechanical strength and stability of the magnetic core, thereby maintaining the normal working performance of the magnetic device, improving its reliability and safety, extending the service life of the magnetic device, and improving its stability and durability in practical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 It is a structural schematic diagram of an existing magnetic core;

[0031] Figure 2 A schematic diagram of the structure of a magnetic device for preventing magnetic core cracking according to the present invention;

[0032] Figure 3 A schematic diagram of the structure of a magnetic core in a magnetic device for preventing the magnetic core from cracking according to the present invention;

[0033] In the figure: 1, magnetic core; 11, bottom edge; 12, side column; 13, middle column; 14, groove; 2, insulating frame; 3, coil. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The object of the present invention is to provide a magnetic device that prevents the magnetic core from cracking, so as to solve the problems existing in the above-mentioned prior art and prevent the magnetic core of the magnetic device from cracking, so as to ensure the mechanical strength of the magnetic core.

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] like Figure 2 and Figure 3 As shown, this embodiment provides a magnetic device for preventing a magnetic core from cracking, comprising an insulating skeleton 2, a coil 3 and two magnetic cores 1 arranged opposite to each other; each magnetic core 1 comprises a U-shaped body and a middle column 13, the U-shaped body comprises a bottom edge 11 and two side columns 12, one end of the bottom edge 11 is fixedly connected to one end of one side column 12, the other end of the bottom edge 11 is fixedly connected to one end of another side column 12, one end of the middle column 13 is fixedly connected to the middle of the middle column 13, and the middle column 13 and the two side columns 12 are located on the same side of the bottom edge 11; the thickness L2 of the bottom edge 11 is greater than or equal to 1.3 times the thickness L1 of the side column 12, the thickness direction of the middle column 13 is parallel to the width direction of the side column 12, and the thickness L3 of the middle column 13 is less than or equal to the width L4 of the side column 12;

[0038] A through hole is provided on the insulating skeleton 2, the middle column 13 of one magnetic core 1 is inserted into the through hole from one end of the through hole, the middle column 13 of the other magnetic core 1 is inserted into the through hole from the other end of the through hole, and the middle columns 13 of the two magnetic cores 1 are bonded, one side column 12 of one magnetic core 1 is bonded to one side column 12 of the other magnetic core 1, and the other side column 12 of one magnetic core 1 is bonded to the other side column 12 of the other magnetic core 1.

[0039] like Figure 1As shown, the magnetic core 1 in the existing magnetic component includes a bottom edge 11 of the magnetic core 1, a groove 14 is arranged on the bottom edge 11, two side pillars 12 of the magnetic core 1, and a middle pillar 13 of the magnetic core 1. The magnetic core 1 of the currently mass-produced magnetic device only adjusts the effective cross-sectional area of ​​the magnetic core 1 from the aspect of magnetic characteristics. Specifically, the area of ​​the middle pillar 13 of the magnetic core 1 of most magnetic devices is twice the cross-sectional area of ​​the side pillar 12, and the cross-sectional area of ​​the side pillar 12 is equal to the cross-sectional area of ​​the bottom edge 11. The thickness ratio between the side pillar 12 and the bottom edge 11 is ignored, resulting in the bottom edge 11 of the magnetic core 1 being cracked due to insufficient mechanical strength in the cold and hot shock test after impregnation. The cracking position is usually located at the groove 14 on the bottom edge 11 of the magnetic core 1.

[0040] Each magnetic core 1 of the present embodiment includes a U-shaped body and a middle column 13 of a specific structure, and the thickness L2 of the bottom edge 11 is greater than or equal to 1.3 times the thickness L1 of the side column 12. This design enables the magnetic core 1 to have better stability and strength distribution in the overall structure. When faced with stress caused by thermal expansion and contraction after impregnation, the stress can be dispersed more effectively to avoid stress concentration in the weak parts of the magnetic core 1, especially the bottom edge 11, thereby greatly reducing the risk of cracking of the magnetic core 1, ensuring the mechanical strength of the magnetic core 1, and then maintaining the carrying capacity of magnetic devices such as transformers, making it more reliable during long-term use, and reducing the possibility of complete damage to the transformer due to cracking of the magnetic core 1. The thickness direction of the middle column 13 is parallel to the width direction of the side column 12, and the thickness L3 of the middle column 13 is less than or equal to the width L4 of the side column 12. Such a structural layout optimizes the stress distribution inside the magnetic core 1, and further enhances the ability of the magnetic core 1 to resist external stress, so that the magnetic core 1 can better maintain its own integrity in a complex working environment and impregnation process, thereby improving the stability and reliability of the magnetic device, ensuring its normal working performance, reducing the change in magnetic flux density distribution caused by structural deformation or cracking of the magnetic core 1, and reducing the adverse effects on the electrical performance of the transformer, such as reducing leakage, maintaining power balance, and reducing harmonic content.

[0041] In this embodiment, each magnetic core 1 is integrally formed, which reduces the connection gaps and structural weaknesses inside the magnetic core 1. During the impregnation process and subsequent use, the integrally formed magnetic core 1 can better resist the stress caused by the difference in thermal expansion coefficients between the insulating paint, the magnetic core 1, the skeleton and the coil 3, avoiding the overall cracking of the magnetic core 1 caused by loose or cracked connection parts, improving the overall strength and stability of the magnetic core 1, ensuring the long-term stable operation of the magnetic device, and at the same time, it is also conducive to maintaining the neatness of the transformer appearance, reducing appearance defects, improving the appearance reliability of the transformer, and extending the service life of the transformer.

[0042] Specifically, the middle columns 13 of the two magnetic cores 1 are bonded by adhesive, one side column 12 of one magnetic core 1 is bonded to one side column 12 of the other magnetic core 1 by adhesive, and the other side column 12 of one magnetic core 1 is bonded to the other side column 12 of the other magnetic core 1 by adhesive. This bonding method forms a tight overall structure between the two magnetic cores 1. After the impregnation treatment, when the product expands and contracts due to changes in ambient temperature, the adhesive can buffer the stress generated by the different thermal expansion coefficients between the magnetic cores 1 and between the magnetic core 1 and other components to a certain extent, and prevent the stress from being excessively concentrated on the body of the magnetic core 1, thereby effectively reducing the possibility of cracking of the magnetic core 1, ensuring the integrity and mechanical properties of the magnetic core 1, and further ensuring the normal operation of the magnetic device, improving its electrical performance and reliability, and reducing various performance degradation problems caused by cracking of the magnetic core 1, such as abnormal magnetic flux density distribution, increased leakage, etc., and also helping to maintain the appearance quality of the transformer and extend its service life.

[0043] In this embodiment, the shape of the bottom edge 11 of the magnetic core 1 is a regular rectangular parallelepiped. This shape design enables the magnetic core 1 to disperse stress more evenly when subjected to force, avoiding stress concentration in weak parts such as corners. During the impregnation process, when subjected to stress caused by thermal expansion and contraction of the insulating paint, the regular rectangular bottom edge 11 can better withstand and transmit stress, reducing the cracking of the bottom edge 11 of the magnetic core 1 caused by stress concentration, thereby ensuring the mechanical strength of the magnetic core 1, maintaining the normal working state of the magnetic device, improving its stability and reliability, reducing the adverse effects of cracking of the magnetic core 1 on the electrical performance and appearance quality of the transformer, and extending the service life of the transformer.

[0044] In this embodiment, the entire magnetic device needs to be impregnated, and the insulating paint used for the impregnation treatment is a self-drying insulating paint or a drying insulating paint; the use of a self-drying insulating paint or a drying insulating paint can improve the mechanical strength, insulation performance and moisture resistance of the magnetic device. Although the impregnation process may generate stress due to the difference in thermal expansion coefficients between the insulating paint and the magnetic core 1 and other components, this problem is effectively overcome through the structural design of the magnetic core 1 and the bonding method of the present invention, so that the magnetic device can obtain the advantages brought by the impregnation treatment while avoiding the risk of cracking of the magnetic core 1, ensuring the stability and reliability of the magnetic device in various working environments, improving its electrical performance and service life, so that it can better meet the strict requirements of magnetic devices such as transformers and inductors in power conversion, signal transmission and electromagnetic compatibility.

[0045] Preferably, the material of the magnetic core 1 is Mn-Zn ferrite or Ni-Zn ferrite, both of which have good magnetic properties and can meet the performance requirements of magnetic devices in terms of electromagnetic conversion, etc. At the same time, combined with the structural design of the present invention to avoid cracking of the magnetic core 1, the magnetic core 1 can better resist stress caused by various factors on the basis of ensuring good magnetic properties, reduce the possibility of cracking of the magnetic core 1, improve the overall performance and reliability of the magnetic device, ensure that it can work stably during long-term use, maintain its electrical and mechanical properties, extend the service life of the magnetic device, and provide a strong guarantee for the efficient operation of equipment such as transformers.

[0046] In the optional scheme of this embodiment, it is more preferred that the cross-sectional shape of the middle column 13 and the side column 12 of the magnetic core 1 is rectangular or circular. This cross-sectional shape design optimizes the structural strength of the magnetic core 1 while ensuring the magnetic properties of the magnetic core 1. The rectangular cross-section can better adapt to the layout and stress conditions of the magnetic core 1 in the magnetic device, and the circular cross-section has better stress distribution uniformity. Both cross-sectional shapes help the magnetic core 1 resist the stress caused by factors such as thermal expansion and contraction, mechanical vibration, etc. during the impregnation process and daily work, reduce the risk of cracking of the magnetic core 1, and ensure the mechanical strength and integrity of the magnetic core 1, thereby maintaining the normal working performance of the magnetic device, improving its reliability and stability, extending the service life of the magnetic device, and reducing the maintenance and replacement costs caused by cracking of the magnetic core 1.

[0047] In the optional scheme of this embodiment, it is more preferred that the material of the insulating skeleton 2 is plastic, which has good insulation performance and certain flexibility. During the operation of the magnetic device, the coil 3 and the magnetic core 1 and other components can be effectively isolated to prevent the occurrence of electrical faults such as short circuits. At the same time, the flexibility of the plastic can buffer the stress caused by thermal expansion and contraction or mechanical vibration to a certain extent, reduce the adverse effects on the magnetic core 1, and cooperate with the structural design of the magnetic core 1 of the present invention and other measures to further reduce the possibility of cracking of the magnetic core 1, improve the overall safety and reliability of the magnetic device, ensure its long-term stable operation, improve its electrical performance and service life, and provide strong support for the reliable application of magnetic devices in various complex environments.

[0048] In this embodiment, a plurality of layers of coils 3 are wound around the through holes on the insulating skeleton 2, and insulating tapes are wound between two adjacent layers of coils 3 and around all coils 3 as a whole. This coil 3 winding method not only ensures the insulation performance of the coils 3, prevents short circuits and leakage between the coils 3, but also protects the magnetic core 1 to a certain extent. The insulating tape can buffer the stress of the coils 3 caused by factors such as current changes and temperature changes, reduce the impact on the magnetic core 1, and cooperate with the structural design of the magnetic core 1 of the present invention and other protective measures to reduce the risk of cracking of the magnetic core 1, ensure the mechanical strength and stability of the magnetic core 1, thereby maintaining the normal working performance of the magnetic device, improving its reliability and safety, extending the service life of the magnetic device, and improving its stability and durability in practical applications.

[0049] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A magnetic device for preventing magnetic core cracking, characterized in that: It comprises an insulating skeleton, a coil and two magnetic cores arranged opposite to each other; each of the magnetic cores comprises a U-shaped body and a middle column, the U-shaped body comprises a bottom edge and two side columns, one end of the bottom edge is fixedly connected to one end of one side column, the other end of the bottom edge is fixedly connected to one end of another side column, one end of the middle column is fixedly connected to the middle of the middle column, and the middle column and the two side columns are located on the same side of the bottom edge; the thickness of the bottom edge is greater than or equal to 1.3 times the thickness of the side column, the thickness direction of the middle column is parallel to the width direction of the side column, and the thickness of the middle column is less than or equal to the width of the side column; A through hole is provided on the insulating skeleton, a middle column of one of the magnetic cores is inserted into the through hole from one end of the through hole, a middle column of another of the magnetic cores is inserted into the through hole from the other end of the through hole, and the middle columns of the two magnetic cores are bonded, a side column of one of the magnetic cores is bonded to a side column of the other magnetic core, and another side column of one of the magnetic cores is bonded to another side column of the other magnetic core.

2. The magnetic device for preventing magnetic core cracking according to claim 1, characterized in that: Each of the magnetic cores is integrally formed.

3. The magnetic device for preventing magnetic core cracking according to claim 1, characterized in that: The middle columns of the two magnetic cores are bonded by adhesive, one side column of one magnetic core is bonded to one side column of the other magnetic core by adhesive, and another side column of one magnetic core is bonded to another side column of the other magnetic core by adhesive.

4. The magnetic device for preventing magnetic core cracking according to claim 1, characterized in that: The shape of the bottom edge is a regular cuboid.

5. The magnetic device for preventing magnetic core cracking according to claim 1, characterized in that: The entire magnetic device needs to be impregnated.

6. The magnetic device for preventing magnetic core cracking according to claim 5, characterized in that: The insulating varnish used in the impregnation treatment is a self-drying insulating varnish or a baking insulating varnish.

7. The magnetic device for preventing magnetic core cracking according to claim 1, characterized in that: The material of the magnetic core is Mn-Zn ferrite or Ni-Zn ferrite.

8. The magnetic device for preventing magnetic core cracking according to claim 1, characterized in that: The cross-sectional shape of the middle column and the side column of the magnetic core is rectangular or circular.

9. The magnetic device for preventing magnetic core cracking according to claim 1, characterized in that: The material of the insulating frame is plastic.

10. The magnetic device for preventing magnetic core cracking according to claim 1, characterized in that: Multiple layers of coils are wound around the locations of the through holes on the insulating frame, and insulating tapes are wound between two adjacent layers of coils and around all the coils as a whole.

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