EMC filtering electromagnetic shielding structure and vehicle-mounted charger

Abstract

The invention discloses an EMC filtering electromagnetic shielding structure which comprises a machine shell, a shielding wall, a top cover arranged on the machine shell, a filtering assembly and a main power assembly, the filtering assembly and the main power assembly are arranged in the machine shell, and a filtering cavity and a main power cavity which are separated by the shielding wall are arranged in the machine shell. The filtering assembly is arranged in the filtering cavity, the main power assembly is arranged in the main power cavity, and the shielding wall and the top cover are in metal connection with an electromagnetic shielding effect. The EMC filtering electromagnetic shielding structure has the advantage of being good in electromagnetic shielding effect. The invention further provides a vehicle-mounted charger adopting the EMC filtering electromagnetic shielding structure.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic shielding, and in particular to an EMC filtering electromagnetic shielding structure and a vehicle-mounted charger using the EMC filtering electromagnetic shielding structure. Background Art

[0002] Electromagnetic compatibility (EMC) refers to the ability of electrical and electronic products to work normally in an electromagnetic environment without causing excessive electromagnetic interference to other products in the environment. The on-board charger (OBC) can be roughly divided into several parts, including high-voltage AC input, high-voltage DC output, low-voltage DC output, and low-voltage signal module. During the AC / DC conversion process, it contains high-frequency controlled power MOS, transformers, inductors, etc. These main power components will generate electric and magnetic field interference during the power conversion process. These interferences will radiate through space and line ends, so AC input and HV output ports are required for processing. The usual practice is to add filtering components to the AC input and HV output ports, and this filtering component needs to have a complete cavity for electromagnetic shielding to prevent electromagnetic interference.

[0003] like Figure 1 As shown, the main power component is usually arranged on the main power board 100, and the filter component is usually integrated on the filter board 200. The filter board 200 is separated from the main power board 100 and placed below the main power board 100. The filter board 200 and the main power board 100 are shielded by a metal shielding cover 300, but since the filter board 200 itself needs to be connected to the main power board 100, considering safety avoidance and connection avoidance, the shielding cover 300 has multiple avoidance openings 310, such as Figure 2 As shown, electromagnetic interference cannot be effectively shielded, and there is electromagnetic interference with the main power board, thus affecting the EMC performance of the entire machine. Summary of the invention

[0004] The purpose of the present invention is to provide an EMC filter electromagnetic shielding structure with good electromagnetic shielding effect and a vehicle-mounted charger using the EMC filter electromagnetic shielding structure in view of the defects of the above-mentioned prior art.

[0005] In an embodiment of the present invention, an EMC filtering electromagnetic shielding structure is provided, which includes: a casing, a shielding wall, a top cover arranged on the casing, and a filter component and a main power component arranged in the casing, wherein a filter cavity and a main power cavity separated by the shielding wall are arranged in the casing, the filter component is arranged in the filter cavity, the main power component is arranged in the main power cavity, and the shielding wall and the top cover maintain a metal connection with an electromagnetic shielding effect.

[0006] In an embodiment of the present invention, the filter component and the main power component are arranged in different areas of the same PCB board, and the board is provided with a groove corresponding to the shielding wall. The shielding wall passes through the groove to separate the filter component and the main power component in the filter cavity and the main power cavity.

[0007] In the embodiment of the present invention, the shielding wall and the casing are formed integrally.

[0008] In an embodiment of the present invention, the filter assembly and the main power assembly are arranged in different areas of the same PCB board, and the PCB board is provided with a groove corresponding to the shielding wall. The shielding wall passes through the groove to separate the filter assembly and the main power assembly in the filter cavity and the main power cavity.

[0009] In the embodiment of the present invention, a convex rib corresponding to the position of the shielding wall is arranged on the inner side of the top cover, the convex rib is metal-connected to the PCB board through a conductor, and the shielding wall is metal-connected to the PCB board through a conductor.

[0010] In the embodiment of the present invention, the top cover and the shielding wall are connected by metal via a conductor.

[0011] In the embodiment of the present invention, a groove corresponding to the shielding wall is provided on the inner side of the top cover, and the shielding wall is inserted into the groove.

[0012] In the embodiment of the present invention, a convex rib corresponding to the shielding wall is arranged on the inner side of the top cover, and the shielding wall and the convex rib are metal-connected via a conductor.

[0013] In the embodiment of the present invention, the top cover and the shielding wall are integrally formed.

[0014] In the embodiment of the present invention, the shielding wall and the housing are metal-connected via a conductor.

[0015] In the embodiment of the present invention, the shielding wall and the casing are connected by metal through welding.

[0016] In the embodiment of the present invention, the top cover is connected to the shielding wall by welding.

[0017] In an embodiment of the present invention, the filter assembly is arranged on an EMC filter circuit board, the main power assembly is arranged on a main power circuit board, the EMC filter circuit board and the main power circuit board are connected by a copper bus bar passing through the filter cavity and the main power cavity, and through holes for the copper bus bar to pass through are arranged on the side walls of the filter cavity and the main power cavity adjacent to the shielding wall, and the gap between the through hole and the copper bus bar is sealed with a conductive adhesive.

[0018] In an embodiment of the present invention, a vehicle-mounted charger is further provided, which includes a vehicle-mounted DCDC conversion module and the above-mentioned EMC filtering electromagnetic shielding structure.

[0019] Compared with the prior art, the EMC filtering electromagnetic shielding structure of the present invention is adopted, a shielding wall is arranged in the casing, the shielding wall separates the filter cavity from the main power cavity, the filter component is arranged in the filter cavity, and the main power component is arranged in the main power cavity, so that the filter component and the main power component are electromagnetically shielded; in addition, the top cover and the shielding wall maintain a metal connection with an electromagnetic shielding effect, which can better separate the filter cavity and the main power cavity, and effectively prevent the main power component from electromagnetic interference with the filter component; furthermore, the filter component and the main power component are arranged in different areas of the same PCB board, and the PCB board is provided with a groove corresponding to the shielding wall, and the shielding wall passes through the groove to separate the filter component and the main power component in the filter cavity and the main power cavity, while improving the EMC shielding performance, it can also reduce the assembly process and reduce the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a three-dimensional structural schematic diagram of an EMC filtering electromagnetic shielding structure in the prior art.

[0021] Figure 2 A schematic plan view of an EMC filtering electromagnetic shielding structure in the prior art.

[0022] Figure 3 It is a schematic diagram of the three-dimensional structure of the EMC filtering electromagnetic shielding structure of an embodiment of the present invention.

[0023] Figure 4 It is a schematic diagram of the three-dimensional structure of the casing according to an embodiment of the present invention.

[0024] Figure 5 It is a schematic diagram of the planar structure of the EMC filtering electromagnetic shielding structure of an embodiment of the present invention.

[0025] Figure 6 It is a structural schematic diagram of a connection method between a shielding wall and a top cover according to an embodiment of the present invention.

[0026] Figure 7 It is a structural schematic diagram of a connection method between a shielding wall and a top cover according to an embodiment of the present invention.

[0027] Figure 8 It is a structural schematic diagram of a connection method between a shielding wall and a top cover according to an embodiment of the present invention.

[0028] Fig. 9It is a structural schematic diagram of a connection method between a shielding wall and a top cover according to an embodiment of the present invention.

[0029] Fig.10 It is a structural schematic diagram of a connection method between a shielding wall and a top cover according to an embodiment of the present invention.

[0030] Fig.11 It is a structural schematic diagram of a connection method between a shielding wall and a top cover according to an embodiment of the present invention.

[0031] Fig.12 It is an electromagnetic radiation waveform diagram of the prior art.

[0032] Fig.13 1 is an electromagnetic radiation waveform diagram of an embodiment of the present invention.

[0033] Fig.14 It is a schematic diagram of the planar structure of an EMC filtering electromagnetic shielding structure according to another embodiment of the present invention. DETAILED DESCRIPTION

[0034] The EMC filter electromagnetic shielding structure of the vehicle-mounted charger is taken as an example to illustrate the EMC filter electromagnetic shielding structure of the present invention.

[0035] like Figure 3-Figure 5 As shown, in an embodiment of the present invention, an EMC filtering electromagnetic shielding structure is provided, which includes: a housing 1, a top cover 2 arranged on the housing 1, and a shielding wall 11 arranged between the housing 1 and the top cover 2. The housing 1 includes a main power cavity 13 and a filter cavity 14 separated by the shielding wall 11. A main power component 15 is arranged in the main power cavity 13, and a filter component 16 is arranged in the filter cavity 14. The filter component includes an HV filter component and an AC filter component. The housing 1 and the top cover 2 are both made of metal, so as to have an electromagnetic shielding effect.

[0036] In this embodiment, two shielding walls 11 are provided in the housing 1, and there are two filter cavities, namely, an HV filter cavity and an AC filter cavity located on both sides of the main power cavity 13. The HV filter assembly is arranged in the HV filter cavity, and the AC filter assembly is arranged in the AC filter cavity. The top cover 2 maintains a metal connection with the shielding wall 11 having an electromagnetic shielding effect, thereby electromagnetically shielding the filter assembly 16 and the main power assembly 15, effectively preventing the main power assembly 15 from electromagnetic interference with the filter assembly 16.

[0037] In this embodiment, the filter assembly 16 and the main power assembly 15 are both arranged on the same PCB board 3, and are respectively arranged in different areas corresponding to the main power cavity 13 and the filter cavity 14. The PCB board 3 is provided with a slot 31 and a plurality of screw holes 32 corresponding to the shielding wall 11, and the housing 1 is also provided with a plurality of studs 17 corresponding to the screw holes 32. During assembly, the shielding wall 11 is passed through the slot 31, the PCB board 2 is covered on the main power cavity 13 and the filter cavity 14, and is fixed by the studs 17, so that the filter assembly 16 and the main power assembly 15 are separated in the filter cavity 14 and the main power cavity 13. The filter assembly 16 and the main power assembly 15 are both arranged on the same PCB board, which can improve the EMC shielding performance while reducing the assembly process and reducing the production cost.

[0038] In the embodiment of the present invention, the shielding wall 11 is made of metal and can be fixed in the housing 1 by welding. The shielding wall 11 can also be integrally formed with the housing 1 to achieve a better EMC shielding effect. In the embodiment of the present invention, the top cover 2 and the shielding wall 11 can be connected to each other by metal in a variety of ways.

[0039] like Figure 6 As shown, in a preferred implementation, the top cover 2 can also maintain a metal connection with the shielding wall 11 through a conductor 4, and the conductor 4 can be conductive foam, metal shrapnel, conductive powder or conductive glue.

[0040] like Figure 7 As shown, in another preferred implementation, a groove 20 corresponding to the shielding wall 11 is provided on the inner side of the top cover 2, and the shielding wall 11 is inserted into the groove 20, thereby forming a metal connection with the top cover 2 having an electromagnetic shielding effect.

[0041] like Figure 8 As shown, in another preferred implementation, a convex rib 21 corresponding to the shielding wall 11 is provided on the inner side of the top cover 2 , and the shielding wall 11 maintains a metal connection with the convex rib 22 through the conductor 4 .

[0042] like Fig. 9 As shown, in another preferred implementation, the top cover 2 and the shielding wall 11 are integrally formed, and the shielding wall 11 and the housing 1 are metal-connected through the conductor 4. The shielding wall 11 can also be metal-connected to the housing 1 by welding. Further, the top cover 2 and the shielding wall 11 can also be connected by welding.

[0043] like Fig.10As shown, in another preferred implementation, the PCB board 3 is not provided with a groove through which the shielding wall 11 passes, and a convex rib 21 corresponding to the position of the shielding wall 11 is provided on the inner side of the top cover 2, and the convex rib 21 and the PCB board 3 are maintained in metal connection through the conductor 4, and the shielding wall 11 and the PCB board 3 are maintained in metal connection through the conductor 4.

[0044] It should be noted that in the various ways in which the top cover 2 and the shielding wall 11 are connected via the conductor 4, the conductor 4 may be provided at all connecting portions between the shielding wall 11 and the top cover 2, or may be provided at connecting portions between the shielding wall 11 and the top cover 2 in sections, such as Fig.11 shown.

[0045] Fig.12 is the EMC radiation test value of the existing technology, Fig.13 It is the EMC radiation test value of the EMC filtering electromagnetic shielding structure according to the embodiment of the present invention. It can be seen that, compared with the prior art, the EMC filtering electromagnetic shielding structure according to the embodiment of the present invention has a lower EMC radiation test value of 10dBμV / m, which has a better electromagnetic shielding effect.

[0046] like Fig.14 As shown, in another embodiment of the present invention, the filter component is arranged on an EMC filter circuit board 31, and the main power component is arranged on a main power circuit board 32. The EMC filter circuit board 31 and the main power circuit board 32 are connected by a copper bus bar 18 passing through the filter cavity 16 and the main power cavity 15. The side walls of the filter cavity 16 and the main power cavity 15 adjacent to the shielding wall 11 are provided with through holes for the copper bus bar to pass through, and the gap between the through hole and the copper bus bar is sealed with conductive glue.

[0047] It should be noted that, in the above-mentioned embodiment, the filter assembly includes an HV filter assembly and an AC filter assembly, and two corresponding filter cavities are respectively arranged in the housing through the shielding wall. In other embodiments, the filter assembly may be one or more filter assemblies, and the filter cavity in the housing may also be divided into one or more corresponding filter cavities by the shielding wall. Those skilled in the art may set it according to the specific situation, and the present invention does not limit this.

[0048] Furthermore, in an embodiment of the present invention, there is also provided a vehicle-mounted charger, which includes a vehicle-mounted DCDC conversion module and the above-mentioned EMC filtering electromagnetic shielding structure.

[0049] In summary, the EMC filter electromagnetic shielding structure of the present invention is adopted, a shielding wall is arranged in the housing, the shielding wall separates the filter cavity from the main power cavity, the filter assembly is arranged in the filter cavity, and the main power assembly is arranged in the main power cavity, so that the filter assembly and the main power assembly are electromagnetically shielded; in addition, the top cover and the shielding wall maintain a metal connection with an electromagnetic shielding effect, which can better separate the filter cavity and the main power cavity, and effectively prevent the electromagnetic interference of the main power assembly to the filter assembly; furthermore, the filter assembly and the main power assembly are arranged in different areas of the same PCB board, and the PCB board is provided with a slot corresponding to the shielding wall, and the shielding wall passes through the slot to separate the filter assembly and the main power assembly in the filter cavity and the main power cavity, while improving the EMC shielding performance, it can also reduce the assembly process and reduce the production cost. The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Any modification, equivalent replacement and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An EMC filtering electromagnetic shielding structure, characterized in that: include: A casing, a shielding wall, a top cover arranged on the casing, and a filter component and a main power component arranged in the casing. The casing is provided with a filter cavity and a main power cavity separated by the shielding wall. The filter component is arranged in the filter cavity, the main power component is arranged in the main power cavity, and the shielding wall and the top cover maintain a metal connection with an electromagnetic shielding effect.

2. The EMC filtering electromagnetic shielding structure according to claim 1, characterized in that: The filter assembly and the main power assembly are arranged in different areas of the same PCB board. The PCB board is provided with a groove corresponding to the shielding wall. The shielding wall passes through the groove to separate the filter assembly and the main power assembly within the filter cavity and the main power cavity.

3. The EMC filtering electromagnetic shielding structure according to claim 1, characterized in that: The filter component and the main power component are arranged in different areas of the same PCB board, and a convex rib corresponding to the position of the shielding wall is arranged on the inner side of the top cover. The convex rib is metal-connected to the PCB board through a conductor, and the shielding wall is metal-connected to the PCB board through a conductor.

4. The EMC filtering electromagnetic shielding structure according to claim 1 or 2, characterized in that: The shielding wall and the casing are integrally formed.

5. The EMC filtering electromagnetic shielding structure according to claim 4, characterized in that: The top cover and the shielding wall are connected by metal via a conductor.

6. The EMC filtering electromagnetic shielding structure according to claim 4, characterized in that: A groove corresponding to the shielding wall is arranged on the inner side of the top cover, and the shielding wall is inserted into the groove.

7. The EMC filtering electromagnetic shielding structure according to claim 4, characterized in that: The inner side of the top cover is provided with convex ribs corresponding to the shielding wall, and the shielding wall and the convex ribs are metal-connected via a conductor.

8. The EMC filtering electromagnetic shielding structure according to claim 1 or 2, characterized in that: The top cover and the shielding wall are integrally formed.

9. The EMC filtering electromagnetic shielding structure according to claim 8, characterized in that: The shielding wall and the housing are connected to each other by metal via a conductor.

10. The EMC filtering electromagnetic shielding structure according to claim 8, characterized in that: The shielding wall and the casing are connected by metal through welding.

11. The EMC filtering electromagnetic shielding structure according to claim 1 or 2, characterized in that: The top cover is connected to the shielding wall by welding.

12. The EMC filtering electromagnetic shielding structure according to claim 1 or 2, characterized in that: The filter assembly is arranged on an EMC filter circuit board, the main power assembly is arranged on a main power circuit board, the EMC filter circuit board and the main power circuit board are connected by a copper bus bar passing through the filter cavity and the main power cavity, and through holes for the copper bus bar to pass through are arranged on the side walls of the filter cavity and the main power cavity adjacent to the shielding wall, and the gap between the through hole and the copper bus bar is sealed with conductive glue.

13. A vehicle-mounted charger, characterized in that: It comprises a vehicle-mounted DCDC conversion module and an EMC filtering electromagnetic shielding structure as described in any one of claims 1 to 12.

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