Plug-in and vehicle plug-in box for vehicle plug-in box

Abstract

The embodiment of the present invention discloses a plug-in for a vehicle-mounted plug-in box and a vehicle-mounted plug-in box. The plug-in for the vehicle-mounted plug-in box includes: a circuit board, the circuit board includes at least two radio frequency circuit areas, the radio frequency circuit area is provided with a radio frequency circuit, the radio frequency circuit is a low-frequency radio frequency circuit with a frequency less than 100 MHz; wherein, at least one of the radio frequency circuit areas is provided with an electromagnetic shielding circuit, the electromagnetic shielding circuit is used to weaken the electromagnetic interference of the radio frequency circuit; corresponding to at least one of the radio frequency circuit areas, a shielding circuit surrounding the radio frequency circuit area is provided; an electromagnetic shielding structure, the electromagnetic shielding structure is located on the side of the circuit board where the shielding circuit is provided; the electromagnetic shielding structure includes a cover body and an isolation portion provided on the cover body, the isolation portion is in direct contact with the shielding circuit. Compared with the prior art, the embodiment of the present invention improves the EMC protection effect of the vehicle-mounted plug-in box.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of railway train electronic equipment, and in particular to a plug-in unit for an on-board plug-in box and the on-board plug-in box. Background Art

[0002] The on-board plug-in box, also known as the on-board plug-in box, is an important type of on-board equipment in railway trains. Depending on the functional requirements, corresponding plug-ins can be configured in the on-board plug-in box. In the prior art, in order to meet the electromagnetic shielding (Electromagnetic Compatibility, EMC) protection requirements of on-board equipment, the plug-in and the on-board plug-in box are usually combined into a self-enclosed EMC protection system. In other words, the focus of EMC protection is on the overall protection of the plug-in box + plug-in to avoid electromagnetic interference (EMI) between the on-board plug-in box as a whole and the outside world.

[0003] However, inside the vehicle-mounted plug-in box, when a radio frequency circuit is provided on the plug-in, the radio frequency circuit will cause electromagnetic interference to other circuits inside the vehicle-mounted plug-in box. Also, since the radio frequency circuits configured in the vehicle-mounted plug-in box are mostly low-frequency radio frequency circuits, their frequency application range is relatively low, generally around 27MHz, therefore, no corresponding electromagnetic shielding design is performed for these radio frequency circuits. This causes the circuit performance of the plug-in itself and the circuit performance of other plug-ins inside the vehicle-mounted plug-in box to produce unpredictable electromagnetic interference effects. It can be seen that the existing vehicle-mounted plug-in box has the problem of poor EMC protection effect. Summary of the invention

[0004] The embodiment of the present invention provides a plug-in unit for a vehicle-mounted plug-in box and a vehicle-mounted plug-in box, so as to improve the EMC protection effect of the vehicle-mounted plug-in box.

[0005] In a first aspect, an embodiment of the present invention provides a plug-in unit for a vehicle-mounted plug-in box, comprising:

[0006] A circuit board, wherein the circuit board comprises at least two radio frequency circuit areas, wherein a radio frequency circuit is arranged in the radio frequency circuit area, and the radio frequency circuit is a low-frequency radio frequency circuit with a frequency less than 100 MHz; wherein at least one of the radio frequency circuit areas is provided with an electromagnetic shielding circuit, and the electromagnetic shielding circuit is used to weaken the electromagnetic interference of the radio frequency circuit; and a shielding line surrounding the radio frequency circuit area is arranged corresponding to at least one of the radio frequency circuit areas;

[0007] The electromagnetic shielding structure is located at a side of the circuit board where the shielding circuit is provided; the electromagnetic shielding structure comprises a cover body and an isolating portion provided on the cover body, and the isolating portion is in direct contact with the shielding circuit.

[0008] Optionally, the radio frequency circuit area includes a first radio frequency circuit area; the first radio frequency circuit area is provided with the electromagnetic shielding circuit, and a shielding line surrounding the first radio frequency circuit area is correspondingly provided;

[0009] The isolation portion of the electromagnetic shielding structure is in direct contact with the shielding line corresponding to the first radio frequency circuit area.

[0010] Optionally, the radio frequency circuit area includes a second radio frequency circuit area and a third radio frequency circuit area; the second radio frequency circuit area is provided with the electromagnetic shielding circuit;

[0011] A shielding circuit surrounding the third RF circuit area is provided corresponding to the third RF circuit area; the isolation portion of the electromagnetic shielding structure is in direct contact with the shielding circuit corresponding to the third RF circuit area.

[0012] Optionally, the number of the third RF circuit areas is at least two; the isolation portion divides the cover body into at least two shielding areas, the shielding areas correspond to the third RF circuit areas, and the isolation portion of the electromagnetic shielding structure is in direct contact with the shielding line corresponding to the third RF circuit area.

[0013] Optionally, the electromagnetic shielding circuit includes an LC series module and an LC parallel module;

[0014] The LC series module is connected in series between the output end of the radio frequency circuit and the radio frequency connector; and the LC parallel module is connected between the LC series module and the ground end.

[0015] Optionally, the number of the LC series modules is at least two, and the number of the LC parallel modules is at least two.

[0016] Optionally, the thickness of the isolation portion is smaller than the width of the shielding line.

[0017] Optionally, the material of the electromagnetic shielding structure includes at least one of aluminum and its alloys; the material of the shielding line includes at least one of copper and its alloys.

[0018] Optionally, a first screw hole is provided on the circuit board, and a second screw hole is provided on the cover body, and the second screw hole corresponds to the first screw hole; the cover body and the circuit board are fixed by screws.

[0019] In a second aspect, an embodiment of the present invention further provides a plug-in as described in any embodiment of the present invention.

[0020] The embodiment of the present invention sets up a mixed application of an electromagnetic shielding circuit and an electromagnetic shielding structure, thereby improving the electromagnetic shielding effect of the plug-in. Among them, the electromagnetic shielding circuit can reduce the electromagnetic interference generated by the radio frequency circuit from the source; the electromagnetic shielding structure has an independent shielding area, which is equivalent to separating different radio frequency circuits through a mechanical structure. And the embodiment of the present invention sets a shielding line around the radio frequency circuit area, and makes the electromagnetic shielding structure and the shielding line directly contact, so that the isolation part of the electromagnetic shielding structure and the isolation belt on the circuit board overlap, which is conducive to the electromagnetic shielding from the perspective of the circuit board in conjunction with the mechanical structure, so that the signals of each radio frequency circuit area are isolated from each other and do not interfere with each other, so as to achieve the effect of electromagnetic protection. In addition, since the frequency of the radio frequency circuit in the embodiment of the present invention is a low-frequency radio frequency circuit, therefore, directly through the electromagnetic shielding structure and the shielding line direct contact, a better electromagnetic shielding effect can be achieved, and there is no need to set a conductive glue sealing connection between the electromagnetic shielding structure and the shielding line. It can be seen that the embodiment of the present invention combines the method of electronic circuits with the method of mechanical structure to solve the electromagnetic shielding problem of each radio frequency circuit, and in practical applications, the electromagnetic shielding circuit and the electromagnetic shielding structure can be flexibly set as needed to improve the EMC protection effect of the vehicle-mounted plug-in box. Therefore, the embodiment of the present invention achieves the effect of good electromagnetic shielding effect and strong versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the structure of a plug-in unit for a vehicle-mounted plug-in box provided by an embodiment of the present invention;

[0022] Figure 2 for Figure 1 Schematic diagram of the internal structure of the electromagnetic shielding structure;

[0023] Figure 3 for Figure 1 Schematic diagram of the structure after removing the electromagnetic shielding structure;

[0024] Figure 4 for Figure 3 A schematic diagram of the enlarged structure of the middle area A1;

[0025] Figure 5 A schematic diagram of the structure of an assembly of a vehicle-mounted plug-in box circuit board and an electromagnetic shielding structure provided by an embodiment of the present invention;

[0026] Figure 6 A schematic diagram of the structure of an electromagnetic shielding circuit provided by an embodiment of the present invention;

[0027] Figure 7 It is a schematic diagram of an electromagnetic interference curve of an existing plug-in for a vehicle-mounted plug-in box;

[0028] Figure 8 A schematic diagram of electromagnetic interference curve of a plug-in unit of a vehicle-mounted plug-in box provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0030] An embodiment of the present invention provides a plug-in unit for a vehicle-mounted plug-in box. Figure 1 A schematic diagram of a plug-in unit for a vehicle-mounted plug-in box provided by an embodiment of the present invention. Figure 2 for Figure 1 Schematic diagram of the internal structure of the electromagnetic shielding structure in Figure 3 for Figure 1 Schematic diagram of the structure after removing the electromagnetic shielding structure. Figure 4 for Figure 3 Schematic diagram of the enlarged structure of area A1 in the middle. Figure 1-Figure 4 , the plug-in for the vehicle-mounted plug-in box includes: a circuit board 10 and an electromagnetic shielding structure 20. The circuit board 10 includes at least two radio frequency circuit areas 11, in which a radio frequency circuit is arranged, and the radio frequency circuit is a low-frequency radio frequency circuit with a frequency less than 100MHz; wherein, at least one radio frequency circuit area 11 is provided with an electromagnetic shielding circuit 14, and the electromagnetic shielding circuit 14 is used to weaken the electromagnetic interference of the radio frequency circuit; corresponding to at least one radio frequency circuit area 11, a shielding circuit surrounding the radio frequency circuit area 11 is arranged. The electromagnetic shielding structure 20 is located on the side of the circuit board 10 where the shielding circuit is arranged; the electromagnetic shielding structure 20 includes a cover body 21 and an isolation part 22 arranged on the cover body 21, and the isolation part 22 is in direct contact with the shielding circuit.

[0031] Among them, a plurality of electronic components 12 are arranged on the circuit board 10, and the electronic components 12 in the RF circuit area 11 and the wires connected to the electronic components 12 on the circuit board 10 constitute the RF circuit in the RF circuit area 11. The RF circuits in different RF circuit areas 11 are used to input or output different RF signals, so there is electromagnetic interference between the RF circuits and between the RF circuits and other circuits. Figure 1 The circuit board 10 is shown to include five RF circuit areas by way of example. In other embodiments, the circuit board may include two, three, four, six or more RF circuit areas, which may be set as needed in practical applications. A low-frequency RF circuit refers to a RF circuit with a frequency less than 100 MHz. Optionally, the frequency range is [20 MHz, 40 MHz]. Specifically, the frequency of the RF circuit on the vehicle-mounted plug-in box circuit board is about 27 MHz.

[0032] The electromagnetic shielding circuit 14 is a circuit that can reduce the unwanted harmonics in the radio frequency circuit and weaken the electromagnetic interference emitted by the radio frequency circuit. Optionally, the electromagnetic shielding circuit 14 is a filter circuit. The electromagnetic shielding circuit 14 can reduce the harmonics in the radio frequency circuit, thereby reducing the generation of electromagnetic interference and reducing the electromagnetic interference and impact of the radio frequency circuit on other circuits.

[0033] The shielding circuit refers to the wire surrounding the RF circuit area 11, which is equivalent to the isolation belt set around the RF circuit area 11, and is used to realize electromagnetic shielding between different RF circuit areas inside the circuit board 10. Exemplarily, the circuit board 10 has a window corresponding to the position of the shielding circuit to expose the surface of the shielding circuit, thereby facilitating direct contact between the isolation part 22 and the shielding circuit to achieve electrical conduction. Optionally, the material of the shielding circuit is the same as that of other circuits on the circuit board 10, and the shielding circuit can be, for example, a copper-plated circuit on the circuit board 10.

[0034] The electromagnetic shielding structure 20 is a mechanical structure that is covered on the circuit board 10 and is used to electromagnetically shield the radio frequency circuit on the circuit board 10. The isolation portion 22 and the cover 21 can enclose a groove to form a space for accommodating the electronic components 12 on the circuit board 10.

[0035] The embodiment of the present invention sets up the mixed application of the electromagnetic shielding circuit 14 and the electromagnetic shielding structure, so as to improve the electromagnetic shielding effect of the plug-in. Among them, the electromagnetic shielding circuit 14 can reduce the electromagnetic interference generated by the radio frequency circuit from the source; the electromagnetic shielding structure 20 has an independent shielding area, which is equivalent to separating different radio frequency circuits through a mechanical structure. And the embodiment of the present invention sets a shielding line around the radio frequency circuit area 11, and makes the electromagnetic shielding structure 20 and the shielding line directly contact, so that the isolation part 22 of the electromagnetic shielding structure 20 and the isolation belt on the circuit board 10 overlap, which is conducive to the electromagnetic shielding from the perspective of the circuit board 10 in conjunction with the mechanical structure, so that the signals of each radio frequency circuit area 11 are isolated from each other and do not interfere with each other, so as to achieve the effect of electromagnetic protection. In addition, since the frequency of the radio frequency circuit in the embodiment of the present invention is a low-frequency radio frequency circuit, a better electromagnetic shielding effect can be achieved by directly contacting the electromagnetic shielding structure 20 and the shielding line, without the need to set a conductive glue sealing connection between the electromagnetic shielding structure 20 and the shielding line.

[0036] It can be seen that the embodiment of the present invention solves the electromagnetic shielding problem of each radio frequency circuit by combining the electronic circuit method and the mechanical structure method. In practical applications, the electromagnetic shielding circuit 14 and the electromagnetic shielding structure can be flexibly set as needed to improve the EMC protection effect of the vehicle-mounted plug-in box. Therefore, the embodiment of the present invention achieves the effect of good electromagnetic shielding effect and strong versatility.

[0037] Based on the above embodiments, there are many specific ways to set the electromagnetic shielding circuit 14 and the electromagnetic shielding structure in the radio frequency circuit area 11. Several of them are described below, but they are not intended to limit the present invention.

[0038] Continue to see Figure 1-Figure 4 In one embodiment of the present invention, optionally, the RF circuit area 11 includes a first RF circuit area 111, the first RF circuit area 111 is provided with an electromagnetic shielding circuit 14, and a corresponding shielding line surrounding the first RF circuit area 111 is provided; the isolation portion 22 of the electromagnetic shielding structure 20 is in direct contact with the shielding line corresponding to the first RF circuit area 111. In the embodiment of the present invention, the electromagnetic shielding circuit 14 is provided in the first RF circuit area 111, and the electromagnetic shielding structure 20 is provided corresponding to the first RF circuit area, which is equivalent to double EMC protection of the RF circuit in the first RF circuit area 111, thereby facilitating further improving the EMC protection effect of the plug-in.

[0039] Continue to see Figure 1-Figure 4 In one embodiment of the present invention, optionally, the RF circuit area 11 includes a second RF circuit area (not shown in the figure) and a third RF circuit area 113; the second RF circuit area is provided with an electromagnetic shielding circuit 14; a shielding line surrounding the third RF circuit area 113 is provided corresponding to the third RF circuit area 113; the isolation portion 22 of the electromagnetic shielding structure 20 is in direct contact with the shielding line corresponding to the third RF circuit area 113. In the embodiment of the present invention, the electromagnetic shielding circuit is only provided in the second RF circuit area, which can reduce the space occupied by the electromagnetic shielding structure 20; the electromagnetic shielding structure 20 is only provided corresponding to the third RF circuit area 113, which is conducive to reducing the area of ​​the circuit board 10 occupied by the electromagnetic shielding circuit.

[0040] Continue to see Figure 1-Figure 4 , in one embodiment of the present invention, optionally, the total number of the first RF circuit area 111 and the third RF circuit area 113 is at least two; Figure 4 In the embodiment, illustratively, the two RF circuit areas 11 located at the bottom are the first RF circuit area 111, and the three RF circuit areas 11 located at the top are the third RF circuit area 113. The isolation portion 22 divides the cover body 21 into at least two shielding areas, and the shielding areas correspond to the first RF circuit area 111 and the third RF circuit area 113, respectively. The isolation portion 22 of the electromagnetic shielding structure 20 is in direct contact with the shielding lines corresponding to the first RF circuit area 111 and the third RF circuit area 113.

[0041] The isolating portion 22 divides the cover body 21 into at least two shielding areas, which means that the isolating portion 22 serves as a boundary line of the shielding areas, and the isolating portion 22 and the cover body 21 can enclose at least two grooves. Figure 2The electromagnetic shielding structure 20 is exemplarily shown to include five grooves, namely five shielding areas. The electromagnetic shielding structure 20 with independent shielding areas provided in the embodiment of the present invention is equivalent to separating different radio frequency circuits through a mechanical structure, thereby achieving low cost, good electromagnetic shielding effect and strong versatility.

[0042] On the basis of the above embodiments, optionally, the isolation part 22 is connected to a fixed potential through a shielding line. Preferably, the isolation part 22 is grounded through a shielding line. Among them, a variety of signal lines are arranged on the circuit board 10. In practical applications, each signal line will be connected to a different electrical signal. In the embodiment of the present invention, the shielding line is arranged to be connected to a fixed potential, so that the electromagnetic shielding structure 20 can be connected to a fixed potential as a whole, thereby maintaining the potential of the electromagnetic shielding structure 20 stable and further improving the electromagnetic shielding performance.

[0043] On the basis of the above embodiments, optionally, the thickness of the isolation portion 22 is smaller than the width of the shielding line. Such a setting is conducive to avoiding the problem that the electronic components 12 on the circuit board 10 affect the assembly of the electromagnetic shielding structure 10. Optionally, the width of the shielding line ranges from [1.5mm, 2.5mm]; the thickness of the isolation portion 22 ranges from [1mm, 2mm]. For example, due to space limitations on the circuit board 10, the width of the shielding line between each RF circuit area is relatively small, which is 2mm. Then, the thickness of the isolation portion 22 of the electromagnetic shielding structure 20 is set to 1.5mm accordingly.

[0044] On the basis of the above embodiments, optionally, the number of shielding lines surrounding each RF circuit area 11 is at least one circle; the isolation part 22 corresponding to the same RF circuit area 11 is in direct contact with at least one circle of shielding lines. For example, the number of shielding lines is two circles, and the isolation part 22 is in contact with the outer circle shielding line, or with the inner circle shielding line; for another example, the number of shielding lines is three circles, and the isolation part 22 is in contact with the middle circle shielding line.

[0045] Based on the above embodiments, optionally, the material of the electromagnetic shielding structure 20 includes at least one of aluminum and its alloys; the material of the shielding line includes at least one of copper and its alloys. Among them, the use of aluminum or aluminum alloy as the electromagnetic shielding structure is light in weight, which is conducive to improving the overall performance of the plug-in while meeting the weight requirements of the vehicle plug-in box circuit board.

[0046] Continue to see Figure 1-Figure 4 On the basis of the above embodiments, the plug-in may further include a radio frequency connector 40 and a connector 50. The circuit board 10 includes a first end and a second end that are arranged opposite to each other. The radio frequency connector 40 is arranged at the first end of the circuit board 10, and the radio frequency connector 10 is used to connect to an external circuit. The connector 50 is arranged at the second end of the circuit board, and the connector is used to be inserted into the vehicle-mounted plug box.

[0047] Figure 5 A schematic diagram of the structure of a vehicle-mounted plug-in box circuit board and an electromagnetic shielding structure provided by an embodiment of the present invention. Figure 2 and Figure 5 On the basis of the above embodiments, optionally, a first screw hole 13 is provided on the circuit board 10, and a second screw hole 23 is provided on the cover body 21, and the second screw hole 23 corresponds to the first screw hole 13; the cover body 21 and the circuit board 10 are fixed by screws. Exemplarily, the screw 30 passes through the first screw hole 13 and the second screw hole 23 in sequence from the back of the circuit board 10, so that the circuit board 10 and the electromagnetic shielding structure 20 are connected and fixed together by the screw 30. The embodiment of the present invention realizes the fixed connection between the circuit board 10 and the electromagnetic shielding structure 20 through a simple mechanical design, and realizes the effects of simple structure, convenient disassembly and assembly, and firm connection.

[0048] On the basis of the above embodiments, there are multiple optional ways to set up the electromagnetic shielding circuit. The following describes the way to set up the electromagnetic shielding circuit, but it is not intended to limit the present invention.

[0049] Figure 6 A schematic diagram of the structure of an electromagnetic shielding circuit provided by an embodiment of the present invention. Figure 6 In one embodiment of the present invention, optionally, the electromagnetic shielding circuit 14 includes an LC series module 141 and an LC parallel module 142; the LC series module 141 is connected in series between the output end of the RF circuit and the RF connector 40; the LC parallel module 142 is connected between the LC series module 141 and the ground end.

[0050] Among them, the LC series module 141 includes a first inductor L1 and a first capacitor C1 connected in series, and the LC parallel module 142 includes a second inductor L2 and a second capacitor C2 connected in parallel. The embodiment of the present invention is configured in this way, and the filtering function can be achieved through the LC series module 141 and the LC parallel module 142, thereby reducing harmonics in the radio frequency circuit, reducing the generation of electromagnetic interference, and reducing the electromagnetic interference and influence of the radio frequency circuit on other circuits. In addition, the LC series module 141 and the LC parallel module 142 have simple structures and are easy to implement.

[0051] Continue to see Figure 6 Optionally, the number of LC series modules 141 is at least two, and the number of LC parallel modules 142 is at least two, which is equivalent to multi-level electromagnetic shielding, which is conducive to improving the electromagnetic shielding effect. Optionally, the parameters of the first inductor L1, the first capacitor C1, the second inductor L2 and the second capacitor C2 can be set according to the number of harmonics filtered out.

[0052] On the basis of the above embodiments, the inventors conducted performance tests on the electromagnetic shielding effects of the embodiments of the present invention. Figure 7 The following is a schematic diagram of an electromagnetic interference curve of an existing plug-in for a vehicle-mounted plug-in box. Figure 8 This is a schematic diagram of an electromagnetic interference curve of a plug-in of a vehicle-mounted plug-in box provided by an embodiment of the present invention. For example, Figure 7 and Figure 8 The comparison diagram of the electromagnetic shielding structure and the electromagnetic shielding structure is shown. The frequency of the test point T1 is selected as 6MHz, the frequency of the test point T2 is selected as 11.05MHz, the frequency of the test point T3 is selected as 16.05MHz, and the frequency of the test point T4 is selected as 27.09MHz. Among them, at test point T1, when the electromagnetic shielding structure is not set, the electromagnetic interference is -31dB, and when the electromagnetic shielding structure is set, the electromagnetic interference is -35dB, and the electromagnetic interference is improved by 4dB; at test point T2, when the electromagnetic shielding structure is not set, the electromagnetic interference is -2.3dB, and when the electromagnetic shielding structure is set, the electromagnetic interference is -2.4dB, and the electromagnetic interference is improved by 0.1dB; at test point T3, when the electromagnetic shielding structure is not set, the electromagnetic interference is -2.7dB, and when the electromagnetic shielding structure is set, the electromagnetic interference is -2.6dB, and the electromagnetic interference is improved by 0.1dB; at test point T4, when the electromagnetic shielding structure is not set, the electromagnetic interference is -61dB, and when the electromagnetic shielding structure is set, the electromagnetic interference is -75dB, and the electromagnetic interference is improved by 14dB. Therefore, combined with the plug-in frequency of the vehicle-mounted plug-in box being about 27MHz, the embodiment of the present invention can improve the electromagnetic interference by 14dB, and the improvement effect is good.

[0053] An embodiment of the present invention further provides a vehicle-mounted plug-in box, which includes at least one plug-in provided by any embodiment of the present invention. The technical principles and effects produced are similar and will not be described in detail here.

[0054] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A plug-in unit for a vehicle-mounted plug-in box, characterized in that: include: A circuit board, wherein the circuit board comprises at least two radio frequency circuit areas, wherein a radio frequency circuit is arranged in the radio frequency circuit area, and the radio frequency circuit is a low-frequency radio frequency circuit with a frequency less than 100 MHz; wherein at least one of the radio frequency circuit areas is provided with an electromagnetic shielding circuit, and the electromagnetic shielding circuit is used to weaken the electromagnetic interference of the radio frequency circuit; and a shielding line surrounding the radio frequency circuit area is arranged corresponding to at least one of the radio frequency circuit areas; An electromagnetic shielding structure, the electromagnetic shielding structure is located on a side of the circuit board where the shielding circuit is provided; the electromagnetic shielding structure comprises a cover body and an isolating portion provided on the cover body, the isolating portion is in direct contact with the shielding circuit; The isolation portion is connected to a fixed potential through a shielding line.

2. The plug-in unit for a vehicle-mounted plug-in box according to claim 1, characterized in that: The radio frequency circuit area includes a first radio frequency circuit area; the first radio frequency circuit area is provided with the electromagnetic shielding circuit, and a shielding line surrounding the first radio frequency circuit area is correspondingly provided; The isolation portion of the electromagnetic shielding structure is in direct contact with the shielding line corresponding to the first radio frequency circuit area.

3. The plug-in unit for a vehicle-mounted plug-in box according to claim 1, characterized in that: The radio frequency circuit area includes a second radio frequency circuit area and a third radio frequency circuit area; the second radio frequency circuit area is provided with the electromagnetic shielding circuit; A shielding circuit surrounding the third RF circuit area is provided corresponding to the third RF circuit area; the isolation portion of the electromagnetic shielding structure is in direct contact with the shielding circuit corresponding to the third RF circuit area.

4. The plug-in unit for a vehicle-mounted plug-in box according to claim 3, characterized in that: The number of the third RF circuit areas is at least two; the isolation portion divides the cover body into at least two shielding areas, the shielding areas correspond to the third RF circuit areas, and the isolation portion of the electromagnetic shielding structure is in direct contact with the shielding line corresponding to the third RF circuit area.

5. The plug-in unit for a vehicle-mounted plug-in box according to claim 1, characterized in that: The electromagnetic shielding circuit includes an LC series module and an LC parallel module; The LC series module is connected in series between the output end of the radio frequency circuit and the radio frequency connector; and the LC parallel module is connected between the LC series module and the ground end.

6. The plug-in unit for a vehicle-mounted plug-in box according to claim 5, characterized in that: The number of the LC series modules is at least two, and the number of the LC parallel modules is at least two.

7. The plug-in unit for a vehicle-mounted plug-in box according to claim 1, characterized in that: The thickness of the isolation portion is smaller than the width of the shielding line.

8. The plug-in unit for a vehicle-mounted plug-in box according to any one of claims 1 to 7, characterized in that: The material of the electromagnetic shielding structure includes at least one of aluminum and its alloys; the material of the shielding line includes at least one of copper and its alloys.

9. The plug-in unit for a vehicle-mounted plug-in box according to any one of claims 1 to 7, characterized in that: The circuit board is provided with a first screw hole, the cover body is provided with a second screw hole, and the second screw hole corresponds to the first screw hole; the cover body and the circuit board are fixed by screws.

10. A vehicle-mounted plug-in box, characterized in that: Comprising at least one insert as claimed in claims 1-9.

Images