External electromagnetic protection device

Abstract

The utility model provides an external electromagnetic protection device. The external electromagnetic protection device comprises a shell and a magnetic core assembly. Wherein an installation cavity is formed in the shell and used for installing the magnetic core assembly. The magnetic core assembly comprises a first magnetic core and a second magnetic core which can be attached and separated, wire clamping grooves are formed in the opposite faces of the first magnetic core and the second magnetic core correspondingly, and when the first magnetic core is attached to the second magnetic core, the wire clamping grooves can be clamped to the peripheral side of the wire harness, so that the first magnetic core and the second magnetic core can wrap the peripheral side of the wire harness, and the wire harness can be wound around the wire harness. Therefore, interference of external electromagnetic waves on the wire harness is suppressed. A protruding limiting protrusion and a concave limiting groove are arranged between the opposite faces of the first magnetic core and the second magnetic core, the limiting protrusion can stretch into and be clamped in the limiting groove so as to limit movement between the first magnetic core and the second magnetic core, and the first magnetic core and the second magnetic core are prevented from sliding relatively when the first magnetic core is attached to the second magnetic core. And thus, the first magnetic core and the second magnetic core can be conveniently and quickly mounted on the peripheral side of the wire harness.

Description

TECHNICAL FIELD

[0001] The utility model relates to harness protection technical field, especially relates to a external electromagnetic protection device. BACKGROUND

[0002] With the degree of automobile electrification, intelligentization is unceasingly improves, electronic equipment is increasingly complex, electromagnetic interference environment is unceasingly complexification, thereby leading to harness to be susceptible to electromagnetic interference.

[0003] At present, in order to avoid the interference of the harness by the electromagnetic, the electromagnetic protection material is generally wrapped on the outer periphery of the harness to avoid the interference of the electromagnetic on the harness.

[0004] However, the electromagnetic protection harness generally installs the electromagnetic protection material on the harness when the wire is produced, which leads to the difficulty in maintenance of the harness during the maintenance process or the decline of the protection ability of the harness maintenance. UTILITY MODEL CONTENTS

[0005] The utility model discloses a external electromagnetic protection device, which can be quickly installed on the harness and provide electromagnetic protection for the harness.

[0006] To solve the above technical problems, the utility model adopts the following technical scheme:

[0007] According to one aspect of the utility model, the utility model provides a external electromagnetic protection device, which is sleeved on the outer periphery of the harness, and comprises: a shell provided with a mounting cavity; a magnetic core assembly accommodated in the mounting cavity; the magnetic core assembly is used for wrapping on the outer periphery of the harness to suppress the interference of external electromagnetic waves on the harness; wherein the magnetic core assembly comprises a first magnetic core and a second magnetic core; the first magnetic core and the second magnetic core can be relatively attached and separated, the opposite surfaces of the first magnetic core and the second magnetic core are all provided with wire clamping grooves, the wire clamping groove on the first magnetic core and the wire clamping groove on the second magnetic core are oppositely arranged to be clamped on the outer periphery of the harness, so that the first magnetic core and the second magnetic core can be sleeved on the outer periphery of the harness; the wire clamping groove penetrates the magnetic assembly along the axial direction of the harness; the opposite surfaces of the first magnetic core and the second magnetic core are provided with a protruding limiting protrusion and a recessed limiting groove, the limiting protrusion can be inserted into and clamped in the limiting groove, and the movement between the first magnetic core and the second magnetic core is limited.

[0008] In one embodiment of the present application, the housing comprises a first shell and a second shell capable of being attached and detached relative to each other; opposite surfaces of the first shell and the second shell are respectively recessed to form a recessed cavity, so that when the first shell is attached to the second shell, the two recessed cavities form the mounting cavity; the first magnetic core and the second magnetic core are limited in the mounting cavity; the recessed cavities gradually decrease in caliber from the middle to the two ends along the direction of the wire harness axis; the outer side surfaces of the first magnetic core and the second magnetic core are attached to the inner walls of the recessed cavities.

[0009] In one embodiment of the present application, the first shell and the second shell are provided with protruding fixing parts at the two ends along the axial direction of the wire harness; the fixing parts extend relative to each other along the axial direction of the wire harness; the fixing parts at the same end of the first shell and the second shell can be attached to each other and can be connected to a fixing member, so that the fixing member can fix the first shell and the second shell.

[0010] In one embodiment of the present application, the fixing parts are provided with external threads on the outer circumferential side; the fixing member is provided with internal threads, so that the fixing member can be connected to the fixing parts through the threads.

[0011] In one embodiment of the present application, the fixing parts are provided with through wire holes; the wire holes extend along the axial direction of the wire harness, so as to pass through the wire harness.

[0012] In one embodiment of the present application, the external electromagnetic shielding device further comprises a gasket; the coil is installed in the wire hole and is sleeved on the outer circumferential side of the wire harness.

[0013] In one embodiment of the present application, the free end of the fixing part is provided with a wire groove; the wire groove penetrates the fixing part along the radial direction of the wire harness, so that the fixing part has elasticity and can be deformed when the fixing member is connected to the fixing part, so as to fasten the wire harness.

[0014] In one embodiment of the present application, the fixing part is provided with a plurality of wire grooves; the plurality of wire grooves are arranged at intervals in the circumferential direction.

[0015] In one embodiment of the present application, the edge of the recessed cavity on the first shell is formed with a first step part; the edge of the recessed cavity on the second shell is formed with a second step part; the first step part can be overlapped on the second step part, so that the first shell and the second shell can be attached together.

[0016] In an embodiment of the present application, the limiting protrusions and the limiting grooves are provided in plurality; the plurality of limiting protrusions and the plurality of limiting grooves are arranged in an axial direction and are arranged correspondingly.

[0017] From the above technical solution, the utility model has at least the following advantages and positive effects:

[0018] In the utility model, the external electromagnetic protection device includes a shell and a magnetic core assembly. The shell is provided with an installation cavity for installing the magnetic core assembly. The magnetic core assembly includes a first magnetic core and a second magnetic core which can be attached and separated. The opposite surfaces of the first magnetic core and the second magnetic core are provided with wire clamping grooves. When the first magnetic core is attached to the second magnetic core, the wire clamping grooves can be clamped on the outer circumferential side of the wire bundle, so that the first magnetic core and the second magnetic core can be wrapped on the outer circumferential side of the wire bundle to suppress the interference of external electromagnetic waves on the wire bundle.

[0019] Meanwhile, the opposite surfaces of the first magnetic core and the second magnetic core are provided with protruding limiting protrusions and recessed limiting grooves. The limiting protrusions can be inserted into and clamped in the limiting grooves to limit the movement between the first magnetic core and the second magnetic core, so as to avoid the relative sliding of the first magnetic core and the second magnetic core when the first magnetic core is attached to the second magnetic core. Thus, the first magnetic core and the second magnetic core can be quickly installed on the outer circumferential side of the wire bundle. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a schematic view of the external electromagnetic protection device of the utility model embodiment.

[0021] Figure 2 is Figure 1 is a sectional view of the external electromagnetic protection device and the wire bundle of the utility model embodiment.

[0022] Figure 3 is Figure 1 is a schematic view of the external electromagnetic protection device of the utility model embodiment.

[0023] Figure 4 is Figure 1 is an exploded view of the external electromagnetic protection device of the utility model embodiment.

[0024] Figure 5 is Figure 4 is another schematic view of the exploded view of the external electromagnetic protection device of the utility model embodiment.

[0025] Figure 6 is Figure 1 is a radial cross-sectional view of the external electromagnetic protection device of the utility model embodiment.

[0026] The reference signs are explained as follows:

[0027] 1 - wire harness; 10 - shell; 11 - mounting cavity; 12 - first housing; 13 - second housing; 14 - concave cavity; 15 - fixed part; 16 - fixing piece; 17 - gasket; 20 - magnetic core assembly; 21 - first magnetic core; 22 - second magnetic core; 23 - wire clamping groove; 121 - first step portion; 131 - second step portion; 151 - external thread; 152 - wire hole; 153 - wire groove; 161 - internal thread; 211 - limiting protrusion; 221 - limiting groove. DETAILED DESCRIPTION

[0028] The typical embodiments embodying the features and advantages of the present application will be described in detail in the following description. It should be understood that the present application can have various changes on different embodiments, which are all not deviated from the scope of the present application, and the description and drawings in essence are used for illustration, not for limiting the present application.

[0029] In the description of the present application, it should be understood that in the embodiments shown in the drawings, the indication of direction or position relationship (such as up, down, left, right, front and back, etc.) is only for the convenience of describing the present application and simplifying the description, and is not intended to indicate or imply that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation. When these elements are in the position shown in the drawings, these descriptions are appropriate. If the position of these elements changes, the indication of direction also changes accordingly.

[0030] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0031] At present, in order to avoid the wire harness from being disturbed by electromagnetic, the electromagnetic protection material is generally wrapped on the outer periphery of the wire harness to avoid the electromagnetic disturbance to the wire harness. However, such electromagnetic protection wire harness generally installs the electromagnetic protection material on the wire harness when the wire is produced, resulting in that the wire harness is difficult to maintain during the maintenance process, or the protection ability of the wire harness at the maintenance position is reduced, etc. Therefore, the present application provides an external electromagnetic protection device to solve the above problems.

[0032] The scheme is further illustrated by the following embodiments:

[0033] Figure 1 is a schematic view of the external electromagnetic protection device and the wire harness of the present application. Figure 2 is Figure 1 is a sectional view of the external electromagnetic protection device and the wire harness ofFigure 3 is Figure 1 a schematic diagram of the external electromagnetic shielding device of the present embodiment.

[0034] Referring to Figure 1 and Figure 2 , the external electromagnetic shielding device of the present embodiment can be sleeved on the outer circumferential side of the wire harness 1 to inhibit the interference of external electromagnetic waves on the wire harness 1. The wire harness 1 can be arranged as a wire for transmitting electric energy, or as a wire for transmitting signals.

[0035] Specifically, the external electromagnetic shielding device can include a shell 10 and a magnetic core assembly 20.

[0036] The shell 10 can be provided with a mounting cavity 11 for accommodating the magnetic core assembly 20 and can play a role in protecting the magnetic core assembly 20.

[0037] The magnetic core assembly 20 can be used to wrap on the outer circumferential side of the wire harness 1 to inhibit the interference of external electromagnetic waves on the wire harness 1.

[0038] In the present embodiment, the magnetic core assembly 20 can be made of a ferromagnetic material, or can be made of an alloy magnetic material. Specifically, the magnetic core assembly 20 can be arranged as a nickel-zinc ferrite core or a manganese-zinc ferrite core, so that the magnetic core assembly 20 can be selected according to actual needs.

[0039] Figure 4 is Figure 1 an exploded schematic diagram of the external electromagnetic shielding device of the present embodiment. Figure 5 is Figure 4 another schematic diagram of the exploded view of the external electromagnetic shielding device of the present embodiment.

[0040] Referring to Figure 4 and Figure 5 , the magnetic core assembly 20 can include a first magnetic core 21 and a second magnetic core 22.

[0041] The first magnetic core 21 and the second magnetic core 22 can be relatively attached and separated, so that the first magnetic core 21 and the second magnetic core 22 can move relative to each other along the radial direction of the wire harness 1, so that the first magnetic core 21 and the second magnetic core 22 can be attached to each other and wrapped on the outer circumferential side of the wire harness 1, or separated from the outer circumferential side of the wire harness 1, thereby facilitating the installation or removal of the first magnetic core 21 and the second magnetic core 22.

[0042] In the present embodiment, the first magnetic core 21 and the second magnetic core 22 are provided with wire clamping grooves 23 on the opposite surfaces, and the wire clamping grooves 23 penetrate the magnetic core assembly along the axial direction of the wire harness 1. The wire clamping grooves 23 penetrate the first magnetic core 21 and the second magnetic core 22 along the axial direction of the wire harness 1, and the wire clamping grooves 23 on the first magnetic core 21 and the second magnetic core 22 can be clamped in the axial direction of the wire harness 1.

[0043] Figure 6 is Figure 1 a radial sectional view of the external electromagnetic shielding device.

[0044] Referring to Figure 4 , Figure 5 and Figure 6 , the clamping wire slots 23 on the first magnetic core 21 and the clamping wire slots 23 on the second magnetic core 22 are oppositely arranged, so that the two clamping wire slots 23 can be clamped on the outer periphery of the wire harness 1, and the first magnetic core 21 and the second magnetic core 22 can be sleeved on the outer periphery of the wire harness 1.

[0045] Specifically, the projection of the clamping wire slot 23 on the radial section is semicircular, so that the two clamping wire slots 23 form a through hole with a circular projection on the radial section after splicing, for threading the wire harness 1.

[0046] In this embodiment, the shape of the clamping wire slot 23 can be adapted to the outer periphery side of the wire harness 1, so that the inner wall of the clamping wire slot 23 can be attached to the outer periphery of the wire harness 1, avoiding magnetic leakage.

[0047] In other embodiments, the projection of the clamping wire slot 23 on the radial section can be set to a rectangular or triangular shape, etc., for threading the wire harness 1.

[0048] Referring to Figure 4 and Figure 5 , a limiting protrusion 211 and a limiting recess 221 can be arranged between the opposite faces of the first magnetic core 21 and the second magnetic core 22. Among them, the limiting protrusion 211 protrudes from the opposite face of the first magnetic core 21, and the limiting recess 221 is recessed in the opposite face of the second magnetic core 22.

[0049] Specifically, the limiting protrusion 211 can extend into and clamp in the limiting recess 221, to limit the movement between the first magnetic core 21 and the second magnetic core 22, so that the first magnetic core 21 is attached to the second magnetic core 22, and when the first magnetic core 21 and the second magnetic core 22 are sleeved on the outer periphery of the wire harness 1, the first magnetic core 21 can avoid sliding relative to the second magnetic core 22, so that the first magnetic core 21 and the second magnetic core 22 can be relatively stably sleeved on the wire harness 1, thereby facilitating the connection and fixation of the first magnetic core 21 and the second magnetic core 22.

[0050] In this embodiment, the limiting protrusion 211 and the limiting recess 221 can be provided with multiple.

[0051] Among them, multiple limiting protrusions 211 and multiple limiting recesses 221 are arranged along the axial direction and distributed on both sides of the clamping wire slot 23, and the limiting protrusion 211 and the limiting recess 221 are correspondingly arranged to facilitate the attachment of the first magnetic core 21 and the clamping wire slot 23.

[0052] Referring toFigure 4 and Figure 5 The shell 10 comprises a first shell 12 and a second shell 13. The first shell 12 and the second shell 13 can be attached and detached relative to each other, so as to facilitate the attachment and detachment of the first shell 12 and the second shell 13 to and from the outer periphery of the magnetic core assembly 20.

[0053] In the present embodiment, the opposite surfaces of the first shell 12 and the second shell 13 are respectively recessed to form a recessed cavity 14. When the first shell 12 is attached to the second shell 13, the two recessed cavities 14 can be spliced to form the mounting cavity 11.

[0054] The first magnetic core 21 and the second magnetic core 22 can be respectively accommodated in the recessed cavities 14 of the first shell 12 and the second shell 13.

[0055] Referring to Figure 2 and Figure 6 The first magnetic core 21 and the second magnetic core 22 are limited in the mounting cavity 11, i.e. the outer peripheral wall of the first magnetic core 21 and the second magnetic core 22 can abut against the inner wall of the recessed cavity 14, so that the first shell 12 and the second shell 13 can limit the first magnetic core 21 and the second magnetic core 22, preventing the first magnetic core 21 and the second magnetic core 22 from moving relative to the wire harness 1 in the radial direction and the axial direction.

[0056] Referring to Figure 2 , Figure 4 and Figure 5 The recessed cavities 14 gradually decrease in diameter from the middle to the two ends along the axis of the wire harness 1, and the first magnetic core 21 and the second magnetic core 22 also gradually decrease in diameter from the middle to the two ends along the axis of the wire harness 1, so that the outer side surface of the first magnetic core 21 and the second magnetic core 22 abuts against the inner wall of the recessed cavity 14, and the first shell 12 and the second shell 13 can limit the first magnetic core 21 and the second magnetic core 22.

[0057] Referring to Figure 4 , Figure 5 and Figure 6 The edge of the recessed cavity 14 on the first shell 12 is formed with a first step portion 121, and the edge of the recessed cavity 14 on the second shell 13 is formed with a second step portion 131. The first step portion 121 can be lapped on the second step portion 131, so that the first shell 12 and the second shell 13 can be attached together. Specifically, when the first shell 12 is lapped on the second shell 13, the first step portion 121 and the second step portion 131 can limit the displacement of the first shell 12 relative to the second shell 13 in the radial direction of the wire harness 1, so as to facilitate the attachment of the first shell 12 and the second shell 13.

[0058] In the embodiment, the first shell 12 and the second shell 13 can be plastic shells or metal shells to position and protect the magnetic core assembly 20.

[0059] Referring to Figure 2 , Figure 3 and Figure 4 , the first shell 12 and the second shell 13 can be provided with protruding fixing portions 15 at both ends along the axial direction of the wire harness 1. The fixing portions 15 extend in the axial direction of the wire harness 1, i.e., the fixing portions 15 at both ends of the first shell 12 extend in the axial direction away from the first shell 12, and the fixing portions 15 at both ends of the second shell 13 extend in the axial direction away from the second shell 13.

[0060] In other embodiments, the fixing portions 15 can also be provided on the circumferential side of the first shell 12 and the second shell 13, so that the first shell 12 and the second shell 13 can be fastened together by the fixing portions 15.

[0061] In the embodiment, the fixing portions 15 at the same end of the first shell 12 and the second shell 13 can be relatively attached and can be connected to the fixing members 16, so that the fixing members 16 can fix the first shell 12 and the second shell 13. The fixing members 16 can be nuts.

[0062] Specifically, the outer circumferential side of the fixing portion 15 can be provided with an external thread 151, and the fixing member 16 can be provided with an internal thread 161, so that the fixing member 16 can be connected to the fixing portion 15 by threading, i.e., the fixing member 16 is connected to the two fixing portions 15 at the same end of the first shell 12 and the second shell 13 by threading. Therefore, the first shell 12 and the second shell 13 are fastened together by the two fixing members 16.

[0063] In other embodiments, the fixing member 16 can be a buckle structure or a cable tie, etc., and is connected to the fixing portion 15 to fasten the first shell 12 and the second shell 13 together.

[0064] Referring to Figure 2 , Figure 4 and Figure 5 , the fixing portion 15 is provided with a through wire hole 152, which extends in the axial direction of the wire harness 1 for threading the wire harness 1.

[0065] Meanwhile, the external electromagnetic protection device can further comprise a gasket 17, the coil is mounted in the wire hole 152 and sleeved on the outer circumferential side of the wire harness 1, that is, the gasket 17 is connected between the wire harness 1 and the fixing part 15, so that the fixing part 15 can be fastened and connected to the wire harness 1 through the gasket 17, and the shell 10 and the magnetic core assembly 20 are prevented from being displaced relative to the wire harness 1, and the electromagnetic protection of the protection device is avoided. The protection device is invalid due to disengagement from the protection position and causes electromagnetic protection of the wire harness 1.

[0066] In the embodiment, the gasket 17 can be made of silica gel material, so that the gasket 17 can have insulation, flexibility and sealing performance.

[0067] Referring to Figure 4 and Figure 5 , the free end of the fixing part 15 can be provided with a wire slot 153. Wherein, the wire slot 153 can penetrate the fixing part 15 along the radial direction of the wire harness 1, so that the fixing part 15 has elasticity, and when the fixing member 16 is connected to the fixing part 15, the fixing part 15 can be deformed, so that the fixing part 15 can be bent towards the central axis of the wire harness 1, and the fixing part 15 can be fitted on the outer circumferential side of the wire harness 1 or the gasket 17, and the shell 10 can be fastened on the wire harness 1.

[0068] In the embodiment, a plurality of wire slots 153 can be provided on the fixing part 15, and the plurality of wire slots 153 are arranged at intervals in the circumferential direction, so that the fixing part 15 can be fastened on the circumferential side of the wire harness 1 or the gasket 17 under the locking of the fixing member 16, and the shell 10 is fastened and connected to the wire harness 1.

[0069] As can be seen from the above, the first magnetic core 21 and the second magnetic core 22 can be relatively fitted and sleeved on the wire harness 1, so that the first magnetic core 21 and the second magnetic core 22 can suppress the interference of external electromagnetic waves on the wire harness 1. The first shell 12 and the second shell 13 can be overlapped with each other to wrap the outer circumferential side of the first magnetic core 21 and the second magnetic core 22, and the first shell 12 and the second shell 13 are fastened together by the fixing member 16 and the gasket 17, and the wire harness 1 is limited, so that the first magnetic core 21 and the second magnetic core 22 are also limited on the wire harness 1. Since the shell 10 and the magnetic core assembly 20 can be sleeved on the wire harness 1, the external electromagnetic protection device can be quickly installed on the wire harness 1.

[0070] While the present application has been described with reference to several exemplary embodiments, it is understood that the words that have been used are words of description and illustration, rather than words of limitation. As mentioned above, the present application is capable of taking many forms of implementation and being practiced in various ways, and the above description is not intended to limit the application in any way, except as required by the appended claims and their equivalents.

Claims

1. An external electromagnetic protection device, sleeved on the outer peripheral side of the wiring harness, characterized in that: The external electromagnetic protection device includes: a housing provided with a mounting cavity; a magnetic core assembly housed in the mounting cavity; the magnetic core assembly being used to wrap around the outer circumference of the wiring harness to suppress interference of external electromagnetic waves on the wiring harness; The magnetic core assembly includes a first magnetic core and a second magnetic core; the first magnetic core and the second magnetic core can be relatively attached to and separated from each other, and a wire clamping groove is provided on the opposite surfaces of the first magnetic core and the second magnetic core. The wire clamping groove on the first magnetic core and the wire clamping groove on the second magnetic core are arranged relative to each other so as to be able to clamp on the outer periphery of the wiring harness, so that the first magnetic core and the second magnetic core can be sleeved on the outer periphery of the wiring harness; the wire clamping groove passes through the magnetic core assembly along the axial direction of the wiring harness; A protruding limiting protrusion and a concave limiting groove are provided between the opposing surfaces of the first magnetic core and the second magnetic core. The limiting protrusion can extend into and engage in the limiting groove to limit the movement between the first magnetic core and the second magnetic core.

2. The external electromagnetic protection device according to claim 1, characterized in that: The shell includes a first shell and a second shell that can be relatively fitted and separated; the opposite surfaces of the first shell and the second shell are respectively recessed to form concave cavities, so that when the first shell is fitted on the second shell, the two concave cavities can form the installation cavity; the first magnetic core and the second magnetic core are confined in the installation cavity; the diameter of the cavity gradually decreases from the middle to the two ends along the axis of the wiring harness; the outer side surfaces of the first magnetic core and the second magnetic core are fitted on the inner wall of the cavity.

3. The external electromagnetic protection device according to claim 2, characterized in that: The first shell and the second shell are provided with protruding fixing parts at both ends along the axial direction of the wiring harness; the fixing parts extend relatively along the axial direction of the wiring harness; the fixing parts at the same end of the first shell and the second shell can be relatively fitted and can be connected to the fixing parts so that the fixing parts can fix the first shell and the second shell.

4. The external electromagnetic protection device according to claim 3, characterized in that: An external thread is provided on the outer peripheral side of the fixing portion; and an internal thread is provided on the fixing piece, so that the fixing piece can be connected to the fixing portion through threads.

5. The external electromagnetic protection device according to claim 3, characterized in that: A penetrating wire hole is formed on the fixing portion; the wire hole extends along the axial direction of the wire harness so as to be used for passing the wire harness.

6. The external electromagnetic protection device according to claim 5, characterized in that: The utility model further comprises a washer, which is installed in the wire hole and sleeved on the outer peripheral side of the wire harness.

7. The external electromagnetic protection device according to claim 3, characterized in that: A wire groove is formed at the free end of the fixing portion, and the wire groove passes through the fixing portion in the radial direction of the wiring harness, so that the fixing portion has elasticity and can be deformed when the fixing piece is connected to the fixing portion to fasten the wiring harness.

8. The external electromagnetic protection device according to claim 7, characterized in that: The fixing portion is provided with a plurality of wire grooves; the plurality of wire grooves are arranged at intervals along the circumferential direction.

9. The external electromagnetic protection device according to claim 2, characterized in that: A first step portion is formed on the edge of the concave cavity on the first shell; a second step portion is formed on the edge of the concave cavity on the second shell; the first step portion can overlap the second step portion so that the first shell and the second shell can fit together.

10. The external electromagnetic protection device according to claim 1, characterized in that: A plurality of the limiting protrusions and the limiting grooves are provided; the plurality of limiting protrusions and the plurality of limiting grooves are arranged at intervals along the axial direction, and the limiting protrusions and the limiting grooves are arranged correspondingly.

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