EMI (Electro-Magnetic Interference) filter with high screen effect

Abstract

The invention, which belongs to the technical field of the filter, provides a high-shielding-effect EMI filter comprising a housing, an inlet wire plug, an outlet wire plug, a filter circuit, a plurality of core-through capacitors, a plurality of electric wires and a reverse elimination module. An outer plate of the shell is a multi-layer composite plate, the multi-layer composite plate comprises a metal layer, a magnetic conductive material layer and a metal layer which are arranged in sequence, two metal plates are arranged in the shell, and the two metal plates and the multi-layer composite plate divide the interior of the shell into a wire inlet shielding bin, a filter circuit shielding bin and a wire outlet shielding bin; the wire inlet plug, the wire outlet plug and the filter circuit are all installed on the shell, the plurality of core-through capacitors are respectively installed on the metal plate, the reverse elimination module is installed on the outer wall of the shell and extends outwards, and the reverse elimination module is used for counteracting interference signals in an interference mode. According to the EMI filter with the high shielding effect provided by the invention, the anti-interference capability of the whole EMI filter is effectively improved, so that the filter has a high shielding characteristic.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of filters, and more particularly relates to an EMI filter with high shielding effectiveness. BACKGROUND

[0002] With the increasing complexity of electromagnetic environment, the electromagnetic protection requirements for electronic equipment are also higher and higher. As a key electronic device for suppressing electromagnetic interference, an EMI filter can effectively suppress the conduction of electromagnetic interference along the device cable and is widely used in electromagnetic shielding bodies such as microwave darkrooms and shielding cabinets. With the increasing shielding effectiveness index of electromagnetic shielding bodies, the shielding effectiveness requirements of the filter itself and the corresponding installation interface are also higher and higher. In some special application scenarios, the structure of the traditional EMI filter cannot meet the use requirements. SUMMARY

[0003] The application aims to provide an EMI filter with high shielding effectiveness to solve the technical problem that the structure of the traditional EMI filter cannot meet the high shielding characteristic requirement in the prior art.

[0004] To achieve the above-mentioned purpose, the technical scheme adopted by the application is as follows: an EMI filter with high shielding effectiveness is provided, which comprises an outer shell, an incoming line plug, an outgoing line plug, a filter circuit, a plurality of core-penetrating capacitors, a plurality of electric wires and a reverse elimination module; the outer plates of the outer shell are all multilayer composite plates, the multilayer composite plates comprise metal layers, magnetic conductive material layers and metal layers arranged in sequence, two metal plates arranged horizontally are fixed in the outer shell, and the inside of the outer shell is divided into an incoming line shielding bin, a filter circuit shielding bin and an outgoing line shielding bin by the two metal plates and the corresponding multilayer composite plates; the incoming line plug and the outgoing line plug are both mounted on the outer shell, the incoming line plug and the outgoing line plug are in communication with the incoming line shielding bin and the outgoing line shielding bin respectively; the filter circuit is mounted in the filter circuit shielding bin, the core-penetrating capacitors are mounted on the metal plates respectively, and the incoming line plug, the core-penetrating capacitors, the filter circuit, the core-penetrating capacitors and the outgoing line plug are connected in sequence through the electric wires; the reverse elimination module is mounted on the outer wall of the outer shell and extends outward, and the reverse elimination module is used for monitoring external interference signals and generating counteracting signals of reverse phase to interfere with and counteract the interference signals.

[0005] In a possible implementation manner, the outer shell is provided with two U-shaped bearing frames arranged in an up-down interval, and mounting grooves arranged in a transverse direction and metal mesh pads mounted in the mounting grooves are formed on the inner walls of the U-shaped bearing frames; the ends of the two metal plates are respectively mounted into three mounting grooves of the two U-shaped bearing frames, and the metal mesh pads are in sealed connection with the metal plates.

[0006] In a possible implementation, one side of the shell is provided with an opening and three cover plates hinged to the shell, the opening corresponds to the incoming line shielding bin, the filter circuit shielding bin and the outgoing line shielding bin; the three cover plates are used to close or open the incoming line shielding bin, the filter circuit shielding bin and the outgoing line shielding bin; the shell is provided with an annular groove arranged around the corresponding opening, the inner wall of the annular groove is provided with a metal mesh pad, and the cover plate is a multi-layer composite board piece; one side of the two metal plates is provided with the metal mesh pad connected with the cover plate.

[0007] In a possible implementation, the shell is provided with two mounting holes respectively communicating with the incoming line shielding bin and the outgoing line shielding bin, the incoming line plug and the outgoing line plug are respectively mounted in the two mounting holes, the mounting hole is provided with a metal mesh cylinder, and the upper and lower ends of the metal mesh cylinder are respectively provided with annular flanges arranged on the inner and outer walls of the shell; the metal plate is provided with a connecting hole arranged through the metal plate, and the core-penetrating capacitor is mounted in the connecting hole; the connecting hole is provided with a metal mesh cylinder, and the upper and lower ends of the metal mesh cylinder are respectively provided with annular flanges arranged on the upper and lower end faces of the metal plate.

[0008] In a possible implementation, the shell is further provided with a base located in the filter circuit shielding bin, and the filter circuit is fixedly arranged on the base; the base is provided with two rotatably connected cover bodies on two sides, and the two cover bodies are abutted to form an independent shielding cavity for closing the filter circuit.

[0009] In a possible implementation, the metal plate and the inner wall of the shell are provided with wire clamps, the base is provided with a wire passing hole communicating with the independent shielding cavity; the electric wire extends along the arrangement of the plurality of wire clamps and passes through the wire passing hole to be connected with the filter circuit; the cover body is provided with an avoiding slot for avoiding the core-penetrating capacitor.

[0010] In a possible implementation, the shell is further provided with two rotating holes, the rotating shafts of the two cover bodies are rotatably connected in the corresponding rotating holes, and the end portions of the rotating shafts are provided with transmission grooves located in the rotating holes; the abutting faces of the two cover bodies are respectively provided with a ball plunger and a positioning hole for connection, and the opposite face of the cover body is provided with a metal mesh pad; the rotating shaft of the cover body is provided with a torsion spring.

[0011] In a possible implementation, the shell is further provided with a plurality of heat dissipation plate pieces corresponding to the base, and the plurality of heat dissipation plate pieces are uniformly arranged at intervals.

[0012] In a possible implementation, the reverse elimination module comprises an electromagnetic sensor, a digital signal processor and an antenna, the electromagnetic sensor monitors the interference signal in real time, the digital signal processor generates a counter-phase cancellation signal, and the antenna emits the cancellation signal to interfere and cancel the interference signal.

[0013] In a possible implementation, the outer side of the shell has a sprayed metal conductive layer.

[0014] The high-screening-effect EMI filter provided by the application has the following advantages: compared with the prior art, the high-screening-effect EMI filter has the shielding characteristics of the filter, which adopts the mode of "subarea filtering-step-by-step isolation-active cancellation" during operation. When the electromagnetic interference signal enters the incoming line shield bin through the incoming line plug, it is first filtered by the core-penetrating capacitor installed on the metal plate. The unique structure of the core-penetrating capacitor has very low impedance to high-frequency interference signals, and can effectively filter the common-mode and differential-mode interference on the cable. The signal filtered by the core-penetrating capacitor is input into the filter circuit shield bin through the wire, and the built-in filter circuit processes the interference of a specific frequency band. The interference signal is further attenuated by various elements on the filter circuit. The processed signal is filtered again by the core-penetrating capacitor on the other side of the metal plate to ensure that the residual interference is fully suppressed, and finally output to the backend device through the outgoing line plug. In this process, the reverse elimination module installed on the outer wall of the shell and extending outward continuously monitors the external electromagnetic environment, and generates a counter-phase cancellation signal after processing the frequency, phase and other characteristic parameters of the interference signal. When the two signals meet in space, they interfere and cancel each other, just like the principle of active noise reduction headphones, achieving dynamic compensation of external interference. Through the EMI filter with this structure, the shortcomings of the traditional filter in shielding effectiveness and environmental adaptability are solved, and the anti-interference ability of the entire EMI filter is effectively improved, so that the filter has high shielding characteristics, thereby meeting the demand for high shielding characteristics of the EMI filter. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0016] Figure 1 The structure of the high-screening-effect EMI filter provided by the embodiment of the application is shown in the following figure. Figure 1

[0017] Figure 2 The structure of the high-screening-effect EMI filter provided by the embodiment of the application is shown in the following figure.​Figure 2 ;

[0018] Figure 3 For Figure 1 enlarged view of A in the middle;

[0019] Figure 4 Connection diagram of the incoming plug and the shell provided by the embodiment of the present application;

[0020] Figure 5 Structure diagram of the EMI filter with high shielding efficiency and the cover provided by the embodiment of the present application;

[0021] Figure 6 Connection diagram of the shell and the rotating shaft provided by the embodiment of the present application;

[0022] Figure 7 Structure diagram of the abutting position of the two covers provided by the embodiment of the present application;

[0023] Figure 8 Installation diagram of the reverse elimination module provided by the embodiment of the present application.

[0024] In the drawings, various reference signs represent:

[0025] 10, shell; 11, incoming plug; 12, outgoing plug; 13, filter circuit; 14, core- through capacitor; 15, metal layer; 16, magnetic material layer; 17, metal plate; 18, incoming shielding bin; 19, filter circuit shielding bin; 20, outgoing shielding bin; 21, electric wire; 22, reverse elimination module; 23, U-shaped bearing frame; 24, installation groove; 25, metal mesh pad; 26, opening; 27, cover plate; 28, mounting hole; 29, metal mesh cylinder; 30, connecting hole; 31, base; 32, cover; 33, independent shielding cavity; 34, wire clamp; 35, wire-through hole; 36, avoiding groove; 37, rotating hole; 38, rotating shaft; 39, transmission groove; 40, ball head plunger; 41, positioning hole; 42, electromagnetic sensor; 43, digital signal processor; 44, antenna. DETAILED DESCRIPTION

[0026] In order to make the technical problems to be solved by the present application, the technical solutions and the beneficial effects clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application.

[0027] It should be noted that when an element is referred to as being “fixed to” or “disposed on” another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it can be directly connected to the other element or indirectly connected to the other element.

[0028] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate directions or positions based on the directions or positions shown in the drawings and are used for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the application.

[0029] In addition, the terms "first", "second", "third", etc. are used only for descriptive purposes and should not be construed as indicating or implying relative importance or an indicated number of technical features. Therefore, features defined with "first", "second", etc. can include one or more of the features explicitly or implicitly. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0030] Please refer to Figures 1 to 8 A high shielding efficiency EMI filter is provided. The high shielding efficiency EMI filter comprises a shell 10, an incoming line plug 11, an outgoing line plug 12, a filter circuit 13, a plurality of core-penetrating capacitors 14, a plurality of electric wires 21 and a reverse elimination module 22. The outer plates of the shell 10 are all multi-layer composite plates, which comprise metal layers 15, magnetic conductive material layers 16 and metal layers 15 arranged in sequence. Two metal plates 17 are fixedly arranged in the shell 10 in a horizontal manner. The interior of the shell 10 is divided into an incoming line shielding compartment 18, a filter circuit shielding compartment 19 and an outgoing line shielding compartment 20 by the two metal plates 17 and the corresponding multi-layer composite plates. The incoming line plug 11 and the outgoing line plug 12 are both mounted on the shell 10 and are in communication with the incoming line shielding compartment 18 and the outgoing line shielding compartment 20, respectively. The filter circuit 13 is mounted in the filter circuit shielding compartment 19. The plurality of core-penetrating capacitors 14 are mounted on the metal plates 17. The incoming line plug 11, the core-penetrating capacitors 14, the filter circuit 13, the core-penetrating capacitors 14 and the outgoing line plug 12 are connected in sequence by the plurality of electric wires 21. The reverse elimination module 22 is mounted on the outer wall of the shell 10 and extends outward. The reverse elimination module 22 is used for monitoring external interference signals and generating counteracting signals of reverse phase to interfere with and counteract the interference signals.

[0031] Compared with the prior art, the EMI filter with high shielding efficiency provided by the application adopts a multilayer composite plate structure formed by sequentially stacking a metal layer 15, a magnetic conductive material layer 16 and the metal layer 15. The structure is constructed by using the electromagnetic reflection characteristics of the metal layer 15 and the magnetic shielding characteristics of the magnetic conductive material layer 16 to form a double shielding layer, which can effectively prevent external electromagnetic interference from penetrating into the filter and suppress the leakage of internal electromagnetic energy. The inside of the shell 10 is divided into three independent areas, namely, an incoming line shielding bin 18, a filter circuit shielding bin 19 and an outgoing line shielding bin 20, by two horizontally arranged metal plates 17. The partition design forms a physically isolated signal transmission channel, avoiding electromagnetic coupling interference between different functional modules. The incoming plug 11 and the outgoing plug 12 are respectively connected to the corresponding shielding bins to form a standard signal input and output interface, ensuring that the interference signals conducted by the cable can only be transmitted in the designated shielding area. During operation, the shielding characteristics of the filter adopt the mode of “partition filtering - step-by-step isolation - active cancellation”. When the electromagnetic interference signal enters the incoming line shielding bin 18 through the incoming plug 11, it is first filtered by the core-penetrating capacitor 14 installed on the metal plate 17. The unique structure of the core-penetrating capacitor 14 has extremely low impedance to high-frequency interference signals, which can effectively filter the common-mode and differential-mode interference on the cable. The preliminarily filtered signal enters the filter circuit shielding bin 19 through the wire 21, and the built-in filter circuit 13 processes the interference of a specific frequency band. The processed signal is further attenuated by various elements on the filter circuit 13. The processed signal is then filtered again by the core-penetrating capacitor 14 on the other metal plate 17 to ensure that the residual interference is fully suppressed, and finally output to the backend device through the outgoing plug 12. In this process, the reverse cancellation module 22 installed on the outer wall of the shell 10 and extending outward continuously monitors the external electromagnetic environment. By real-time acquisition of the frequency, phase and other characteristic parameters of the interference signal, the reverse cancellation module 22 generates a cancellation signal with opposite phase after processing. When the two signals meet in space, they interfere with each other and cancel each other out, just like the principle of active noise reduction headphones, achieving dynamic compensation for external interference. Through the EMI filter with this structure, the shortcomings of traditional filters in shielding efficiency and environmental adaptability are solved, and the anti-interference ability of the entire EMI filter is effectively improved, so that the filter has high shielding characteristics, thereby meeting the demand for high shielding characteristics of the EMI filter.

[0032] The EMI filter constructs a three-dimensional shielding system by means of the multi-layer composite plate and the design of the partitioned shielding bin, and compared with the single metal shell 10 of the traditional filter, the electromagnetic shielding effectiveness is greatly improved, especially in the microwave darkroom and other scenes with strict requirements on shielding effectiveness; and the cascading design of the double-core-penetration capacitor 14 and the filter circuit 13 forms a multi-stage filter network, which can achieve a large amount of attenuation for the conducted interference of different types of cables such as power lines and signal lines, which is much higher than the traditional single-stage filter structure. The introduction of the reverse elimination module 22 realizes the combination of passive shielding and active cancellation, which can not only cope with fixed frequency band interference, but also dynamically adapt to complex electromagnetic environment.

[0033] Please refer to Figures 1 to 5 As a specific embodiment of the high-shielding EMI filter provided by the application, the shell 10 is provided with two U-shaped bearing frames 23 arranged in an upper and lower interval, and the inner wall of the U-shaped bearing frame 23 is provided with a transversely arranged mounting groove 24 and a metal mesh pad 25 mounted in the mounting groove 24; the ends of the two metal plates 17 are respectively mounted into the three mounting grooves 24 of the two U-shaped bearing frames 23, and form a sealed connection with the metal mesh pad 25. The shell 10 is provided with two U-shaped bearing frames 23 arranged in an upper and lower interval, and the inner wall of the U-shaped bearing frame 23 is provided with a transversely arranged mounting groove 24 and a metal mesh pad 25 mounted in the mounting groove 24; the ends of the two metal plates 17 are respectively mounted into the three mounting grooves 24 of the two U-shaped bearing frames 23, and form a sealed connection with the metal mesh pad 25. This design provides stable support for the metal plate 17 through the U-shaped bearing frame 23, and uses the elastic conductive properties of the metal mesh pad 25 to build a continuous conductive path between the metal plate 17 and the shell 10, eliminate the electromagnetic leakage gap at the joint, and ensure the complete electromagnetic isolation of the incoming line shielding bin 18, the filter circuit shielding bin 19 and the outgoing line shielding bin 20. The flexible contact of the metal mesh pad 25 can not only adapt to slight deformation and ensure the sealing reliability in long-term vibration environment, but also simplify the installation process of the metal plate 17 and realize the modular structure of the metal plate 17. Through this structure, the electromagnetic sealing performance between the shielding bins is significantly improved, the electromagnetic leakage at the joint is reduced by more than 70%, the structural stability is enhanced, and the long-term reliable operation under complex working conditions is adapted, which provides key structural protection for high shielding effectiveness index.

[0034] Please refer to Figure 1 and Figure 2As a specific embodiment of the high-screening-effect EMI filter provided by the application, one side of the shell 10 is provided with an opening 26 and three cover plates 27 hinged to the shell 10, the opening 26 corresponds to the incoming line shielding chamber 18, the filter circuit shielding chamber 19 and the outgoing line shielding chamber 20; the three cover plates 27 are used to close or open the incoming line shielding chamber 18, the filter circuit shielding chamber 19 and the outgoing line shielding chamber 20; the shell 10 is provided with an annular groove arranged around the corresponding opening 26, the inner wall of the annular groove is provided with a metal mesh pad 25, and the cover plate 27 is a multi-layer composite board; one side of the two metal plates 17 is provided with a metal mesh pad 25 connected with the cover plate 27. The shell 10 is provided with an opening 26 corresponding to the three shielding chambers on one side, and three hinged cover plates 27 are arranged to independently open and close the incoming line shielding chamber 18, the filter circuit shielding chamber 19 and the outgoing line shielding chamber 20, the annular groove at the opening 26 is embedded with a metal mesh pad 25, and the side edge of the metal plate 17 is also connected with the cover plate 27 through the metal mesh pad 25. This design continues the metal-magnetic conductive material-metal shielding structure of the shell 10 through the multi-layer composite cover plate 27, the metal mesh pad 25 in the annular groove and the cover plate 27 form an elastic conductive seal, the conductive deformation characteristics of the metal mesh pad 25 are used to fill the fine gap between the cover plate 27 and the shell 10, and the electromagnetic leakage channel at the opening 26 is eliminated; at the same time, the metal plate 17 is closely attached to the cover plate 27 through the side metal mesh pad 25, so that the incoming line shielding chamber 18, the filter circuit shielding chamber 19 and the outgoing line shielding chamber 20 form a complete electromagnetic isolation cavity when the cover plate 27 is closed. In this way, the detachable maintenance of each shielding chamber is realized, and the electromagnetic leakage amount at the joint of the cover plate 27 is reduced through the conductive sealing design of the metal mesh pad 25.

[0035] Please refer to Figures 1 to 4As a specific embodiment of the high-screening-effect EMI filter provided by the application, two mounting holes 28 are arranged on the shell 10 and connected with the incoming line shielding chamber 18 and the outgoing line shielding chamber 20 respectively, the incoming line plug 11 and the outgoing line plug 12 are mounted in the two mounting holes 28 respectively, the metal mesh cylinder 29 is arranged in the mounting hole 28, and the upper and lower ends of the metal mesh cylinder 29 are both provided with annular flanges, and the two annular flanges are arranged on the inner and outer walls of the shell 10 respectively; the metal plate 17 is provided with a connecting hole 30 arranged in a penetrating manner, and the through-hole capacitor 14 is mounted in the connecting hole 30; the metal mesh cylinder 29 is arranged in the connecting hole 30, and the upper and lower ends of the metal mesh cylinder 29 are both provided with annular flanges, and the two annular flanges are arranged on the upper and lower end faces of the metal plate 17 respectively. The mounting hole 28 is arranged at the corresponding position of the incoming line shielding chamber 18 and the outgoing line shielding chamber 20 of the shell 10, the metal mesh cylinder 29 is embedded in the mounting hole 28, and the annular flanges at the upper and lower ends thereof are fixed on the inner and outer walls of the shell 10 respectively; the metal mesh cylinder 29 with the annular flanges is also mounted in the connecting hole 30 of the metal plate 17, and the through-hole capacitor 14 is embedded therein. The metal mesh cylinder 29 is used to build a conductive shielding channel: the metal mesh cylinder 29 at the mounting hole 28 and the annular flanges form a continuous conductive structure between the plug and the shell 10, so that the electromagnetic leakage of the mounting gap of the incoming line plug 11 and the outgoing line plug 12 is eliminated; the metal mesh cylinder 29 at the connecting hole 30 of the metal plate 17 ensures the close electrical connection between the through-hole capacitor 14 and the metal plate 17, so that the interference coupling between the filter circuit 13 and the shielding chamber is avoided. The mesh structure of the metal mesh cylinder 29 has both elastic deformation and conductive properties, which can not only adapt to the slight displacement during the installation of the incoming line plug 11, the outgoing line plug 12 and the through-hole capacitor 14, but also form a sealed shielding interface through the crimping of the annular flanges. Through the combined design of the metal mesh cylinder 29 and the annular flanges, a full-path shielding system from the shell 10 to the metal plate 17 is built.

[0036] Please refer to Figure 5As a specific embodiment of the high-screening EMI filter provided by the application, the housing 10 is further provided with a base 31 located in the filter circuit shielding bin 19, and the filter circuit 13 is fixed on the base 31; the two sides of the base 31 are respectively provided with rotatably connected cover bodies 32, and the two cover bodies 32 are butted to form an independent shielding cavity 33 for closing the filter circuit 13. The filter circuit 13 is supported by the base 31, and the two side cover bodies 32 are rotatably connected to realize quick opening and closing, and when butted, a complete shielding cavity is formed by the metal mesh pad 25 or the conductive sealing structure, prolonging the electromagnetic shielding performance of the multi-layer composite plate of the housing 10. When the independent shielding cavity 33 is not needed, the two cover bodies 32 are rotated to eliminate the further closing of the filter circuit 13, so that the heat dissipation performance of the filter circuit 13 is improved. The independent shielding cavity 33 physically isolates the filter circuit 13 from the incoming line shielding bin 18 and the outgoing line shielding bin 20, which can prevent external interference signals from being directly coupled to the filter circuit 13 and can also suppress the electromagnetic energy leakage of the filter circuit 13 when working, forming a double shielding structure of “bin in bin”. The electromagnetic leakage of the filter circuit 13 region is greatly reduced by the independent shielding cavity 33, and the sealing design of the base 31 and the cover body 32 makes the shielding effectiveness of the filter significantly improved.

[0037] Please refer to Figure 5 As a specific embodiment of the high-screening EMI filter provided by the application, the metal plate 17 and the inner wall of the housing 10 are provided with wire clamps 34, and the base 31 is provided with a wire passing hole 35 connected with the independent shielding cavity 33; the electric wires 21 extend along the arrangement of the plurality of wire clamps 34 and pass through the wire passing hole 35 to be connected with the filter circuit 13; and the cover body 32 is provided with an avoiding groove 36 for avoiding the through-core capacitor 14. The wire clamps 34 are used to arrange the electric wires 21 in order and close to the metal plate 17 and the inner wall of the housing 10, so as to avoid interference with the cover body 32; and the interference coupling between the electric wires 21 is also effectively avoided; then the electric wires 21 are connected with the filter circuit 13 after entering the inside of the independent shielding cavity 33 through the wire passing hole 35, so as to ensure that the electric wires 21 are connected in order without damaging the sealing structure. The avoiding groove 36 is arranged so that when the cover body 32 is in the open state, the cover body 32 will not touch the through-core capacitor 14.

[0038] Please refer to Figures 5 to 7As a specific embodiment of the high-screening EMI filter provided by the application, the shell 10 is further provided with two rotating holes 37, and the rotating shafts 38 of the two cover bodies 32 are respectively rotatably connected to the corresponding rotating holes 37, and the end portions of the rotating shafts 38 are provided with transmission grooves 39 located in the rotating holes 37. The abutting surfaces of the two cover bodies 32 are respectively provided with ball head plungers 40 and positioning holes 41 for connection, and the opposite surface of the cover body 32 is provided with a metal mesh pad 25. The rotating shaft 38 of the cover body 32 is provided with a torsion spring. The shell 10 is provided with the rotating hole 37 for mounting the rotating shaft 38 of the cover body 32, and the end portion of the rotating shaft 38 is provided with the transmission groove 39 for facilitating adjustment with a tool. The rotating shaft 38 is provided with the torsion spring to keep the two cover bodies 32 in a stable open state, and the abutting surface of the cover body 32 is quickly locked through the ball head plunger 40 and the positioning hole 41, and the contact surface is embedded with the metal mesh pad 25 to form a conductive seal, so as to ensure that the two cover bodies 32 keep a stable closed state. In this way, the two cover bodies 32 are in a stable closed state under the cooperation of the ball head plunger 40 and the positioning hole 41, so as to form a stable independent shielding cavity 33, eliminate the electromagnetic leakage path of the abutting gap of the cover body 32, realize tool-free quick disassembly through the cooperation of the ball head plunger 40 and the positioning hole 41, and the transmission groove 39 provides an operation interface for shaft adjustment. Specifically, the end portion of the rotating shaft 38 is located in the rotating hole 37, and the transmission groove 39 is an internal hexagonal groove, which is convenient for operation with a tool. In this way, the magnetic leakage amount of the abutting portion of the cover body 32 is effectively reduced, and the shielding efficiency is improved.

[0039] As a specific embodiment of the high-screening EMI filter provided by the application, a plurality of uniformly spaced heat dissipation plates are arranged on the shell 10 corresponding to the position of the base 31, and the heat dissipation plates are directly attached to the base 31 and the filter circuit 13 area. The heat generated during the operation of the filter circuit 13 is quickly conducted out through the heat conduction characteristics of the metal material. The interval arrangement design not only increases the heat dissipation area and improves the heat dissipation efficiency, but also does not damage the electromagnetic shielding structure of the multi-layer composite plate of the shell 10.

[0040] Please refer to Figure 1 , Figure 2 and Figure 8As a specific embodiment of the high-screening-effect EMI filter provided by the application, the reverse elimination module 22 comprises an electromagnetic sensor 42, a digital signal processor 43 and an antenna 44, the electromagnetic sensor 42 monitors the interference signal in real time, the digital signal processor 43 generates a reverse-phase cancellation signal, and the antenna 44 emits the cancellation signal to interfere and cancel the interference signal. The reverse elimination module 22 is composed of the electromagnetic sensor 42, the digital signal processor 43 and the antenna 44. The electromagnetic sensor 42 collects the frequency, phase and other parameters of the external interference signal in real time, the digital signal processor 43 generates a reverse-phase cancellation signal based on the real-time data, and the cancellation signal is emitted through the antenna 44 to interfere and cancel the interference signal, thereby forming an active anti-interference mechanism. This design combines passive shielding and active cancellation, and can dynamically respond to changes in complex electromagnetic environments.

[0041] As a specific embodiment of the high-screening-effect EMI filter provided by the application, a metal conductive layer is sprayed on the outer side of the shell 10 to form a continuous electromagnetic shielding surface. The metal conductive layer uniformly covers the surface of the shell 10 through a spraying process, cooperates with the internal multi-layer composite board structure to form a synergistic shielding effect, fills the electromagnetic leakage channels caused by the joints and surface defects of the shell 10, and enhances the reflection and attenuation ability of the high-frequency interference signal.

[0042] The above is only a preferred embodiment of the application, and is not intended to limit the application. Any modification, equivalent replacement and improvement made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A high screening effectiveness EMI filter, characterized in that, The utility model provides a filter circuit, a plurality of core -piercing capacitors, a plurality of wires and reverse elimination module are included in the shell, the incoming line plug, the outgoing line plug, the filter circuit, a plurality of core -piercing capacitors, a plurality of wires and reverse elimination module;The outer plate of shell is all multilayer composite board, and the multilayer composite board includes the metal layer, the magnetic conductive material layer, the metal layer arranged gradually, two metal plates are fixed in the shell and are arranged horizontally, two metal plates and corresponding multilayer composite board divide the shell inside into incoming line shield storehouse, filter circuit shield storehouse and outgoing line shield storehouse;The incoming line plug and the outgoing line plug are all installed on the shell, and the incoming line plug, the outgoing line plug are linked with the incoming line shield storehouse, the outgoing line shield storehouse respectively;The filter circuit is installed in the filter circuit shield storehouse, and a plurality of core -piercing capacitors are installed on the metal plate respectively, and the incoming line plug, the core -piercing capacitor, the filter circuit, the core -piercing capacitor and the outgoing line plug are connected in proper order through a plurality of wires;The reverse elimination module is installed on the outer wall of shell, and extends outward, and the reverse elimination module is used for monitoring external interference signal, and generates the offset signal of reverse phase and interferes with the interference signal and cancels out.

2. The high-screening EMI filter of claim 1, wherein, Two U-shaped bearing frames are arranged in the shell, and the inner wall of the U-shaped bearing frame is provided with a transversely arranged mounting groove and a metal mesh pad mounted in the mounting groove.

3. The high-screening-efficiency EMI filter of claim 2, wherein, One side of the shell is provided with an opening and three cover plates hinged to the shell, and the opening corresponds to the incoming line shield storehouse, the filter circuit shield storehouse and the outgoing line shield storehouse. The three cover plates are used to close or open the incoming line shield storehouse, the filter circuit shield storehouse and the outgoing line shield storehouse.

4. The high-screening-efficiency EMI filter of claim 1, wherein, The shell is provided with an annular groove arranged around the corresponding opening, and the inner wall of the annular groove is provided with a metal mesh pad.

5. The high-screening-efficiency EMI filter of claim 1, wherein, The shell is provided with two mounting holes respectively communicating with the incoming line shield storehouse and the outgoing line shield storehouse, and the incoming line plug and the outgoing line plug are respectively installed in the two mounting holes. The shell is further provided with a base in the filter circuit shield storehouse, and the filter circuit is fixedly arranged on the base. The two sides of the base are respectively provided with a cover body connected in rotation, and the two cover bodies are abutted to form an independent shielding cavity for closing the filter circuit.

6. The high-screening-efficiency EMI filter of claim 5, wherein, The metal plate and the inner wall of the shell are provided with wire clamps, the base is provided with wire holes communicating with the independent shielding cavities; the electric wires extend along the arrangement of the wire clamps and are connected with the filter circuit through the wire holes; the cover is provided with avoiding grooves for avoiding the through-core capacitors.

7. The high-screening-efficiency EMI filter of claim 6, wherein, The shell is further provided with two rotating holes, the rotating shafts of the two covers are respectively rotatably connected in the corresponding rotating holes, and the end portions of the rotating shafts are provided with transmission grooves in the rotating holes; the abutting surfaces of the two covers are respectively provided with ball head plungers and positioning holes for connection, and the opposite surfaces of the covers are provided with metal mesh pads; the rotating shafts of the covers are provided with torsional springs.

8. The high-screening-efficiency EMI filter of claim 5, wherein, The shell is further provided with a plurality of heat dissipation plate pieces corresponding to the base, and the plurality of heat dissipation plate pieces are uniformly arranged at intervals.

9. The high-screening-efficiency EMI filter of claim 1, wherein, The reverse elimination module comprises an electromagnetic sensor, a digital signal processor and an antenna, the electromagnetic sensor monitors interference signals in real time, the digital signal processor generates a reverse phase cancellation signal, and the antenna emits the cancellation signal to interfere and cancel the interference signal.

10. The high-screening-efficiency EMI filter of claim 1, wherein, The outer side surface of the shell has a sprayed metal conductive layer.

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