Electromagnetic shielding ventilation device

Abstract

The invention discloses an electromagnetic shielding ventilation device. The electromagnetic shielding ventilation device comprises an upper bottom plate which is used for totally reflecting electromagnetic waves; the lower bottom plate is used for ventilation; the unequal-distance spiral structure is located between the upper bottom plate and the lower bottom plate, and the unequal-distance spiral structure is used for reflecting and consuming electromagnetic waves of different frequencies. Through the unique spiral shape design, electromagnetic waves can be effectively reflected and dissipated, high-frequency broadband electromagnetic shielding is achieved, meanwhile, a large ventilation caliber can be achieved through the spiral structure, and the good ventilation effect is achieved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of electromagnetic shielding, and in particular to an electromagnetic shielding ventilation device. Background Art

[0002] With the rapid development of modern electronic technology, the widespread application of high-frequency electronic equipment and wireless communication systems, the electromagnetic environment is becoming increasingly complex, and the problems of electromagnetic interference (EMI) and electromagnetic radiation (EMR) are becoming increasingly prominent. This not only interferes with the normal operation of the equipment, but may also cause information leakage and cause huge losses. For electromagnetic environments that require ventilation, electromagnetic shielding windows can provide efficient electromagnetic shielding, effectively suppress the transmission and radiation of electromagnetic waves, ensure the normal operation of electronic equipment and electromagnetic information security, while maintaining good ventilation effects to meet the needs of equipment heat dissipation and air circulation.

[0003] For some low-frequency or low-shielding places, the simplest metal wire mesh or perforated metal plane is used for electromagnetic shielding. However, due to the simple structure of the metal wire mesh and the low electromagnetic shielding performance, the scope of use is very limited. Due to the shortcomings of the metal wire mesh, most of the ventilation waveguide windows on the market are used for ventilation electromagnetic shielding. The main structure of the ventilation waveguide window is an aluminum alloy profile assembled and welded honeycomb cutoff waveguide ventilation plate, which is mainly used in the ventilation openings of electromagnetic shielding facilities and has good shielding and ventilation dual functions. The cross-sectional form of the ventilation cutoff waveguide window is usually round, square and hexagonal.

[0004] However, with the increase of electromagnetic wave frequency, the performance of conventional cutoff waveguide tubes is not enough to meet the requirements of some places with high electromagnetic shielding effectiveness. Usually, an absorbing coating is added to the waveguide window structure or a structural absorbing material is used to improve the performance of the waveguide window. The most common is a honeycomb waveguide structure with a coating. In order to study the influence of the coating or the added structure on the cutoff waveguide, domestic and foreign scholars have done a lot of research. The electromagnetic waveguide window and the waveguide window structure with added coating adopt a simple metal straight tube structure. The electromagnetic wave is reflected and consumed by the tube wall, propagates forward in a zigzag manner, and finally a small part of the electromagnetic wave leaks to the outside world. With the increase of electromagnetic wave frequency, the wavelength of the electromagnetic wave becomes shorter, but the aperture of the metal waveguide tube cannot be infinitely reduced, which will cause the leakage of electromagnetic waves, making it difficult to achieve a higher electromagnetic shielding effect. At the same time, due to the reduction of the aperture of the cutoff waveguide window, the ventilation efficiency is greatly reduced, and a good ventilation effect cannot be achieved. In summary, the existing electromagnetic shielding ventilation device has the problem of being difficult to achieve a higher electromagnetic shielding and being unable to achieve a good ventilation effect. Summary of the invention

[0005] The present invention provides an electromagnetic shielding ventilation device, which can effectively reflect and dissipate electromagnetic waves through a unique spiral shape design to achieve high-frequency broadband electromagnetic shielding. At the same time, the spiral structure can achieve a large ventilation aperture and achieve a good ventilation effect.

[0006] According to one aspect of the present invention, an electromagnetic shielding ventilation device is provided, the electromagnetic shielding ventilation device comprising:

[0007] An upper base plate, the upper base plate is used for total reflection of electromagnetic waves;

[0008] A lower bottom plate, the lower bottom plate is used for ventilation;

[0009] An unequal-pitch spiral structure, wherein the unequal-pitch spiral structure is located between the upper base plate and the lower base plate, and is used for reflecting and consuming electromagnetic waves of different frequencies.

[0010] Optionally, the unequal-pitch spiral structure comprises an unequal-pitch metal involute spiral structure.

[0011] Optionally, the upper base plate, the lower base plate and the unequally spaced spiral structure are all made of iron.

[0012] Optionally, the lower base plate and the unequally spaced spiral structure are integrally formed.

[0013] Optionally, the size of the upper base plate includes 110 mm×110 mm, and the thickness of the upper base plate includes 5 mm.

[0014] Optionally, a spiral groove is provided on the back side of the upper base plate;

[0015] The upper base plate and the unequally spaced spiral structure are embedded through the spiral groove.

[0016] Optionally, the width of the spiral groove is 5 mm, and the depth of the spiral groove is 2.5 mm.

[0017] Optionally, a first countersunk screw hole is arranged on the spiral groove, and a second countersunk screw hole is arranged on the unequally spaced spiral structure, and the positions of the first countersunk screw hole and the second countersunk screw hole correspond to each other.

[0018] Optionally, the diameter of the first countersunk screw hole comprises 3.8 mm, and the depth of the first countersunk screw hole comprises 3 mm;

[0019] A diameter of the second countersunk screw hole comprises 3.8 mm, and a depth of the second countersunk screw hole comprises 3 mm.

[0020] Optionally, a vent is provided on the lower base plate, and a diameter of the vent is 20 mm.

[0021] The technical solution of the embodiment of the present invention provides an electromagnetic shielding ventilation device with an unequally spaced involute spiral as the structural basis in order to achieve high-frequency electromagnetic shielding with good ventilation performance. The unequally spaced spiral structure can effectively reflect and dissipate electromagnetic waves through the unique spiral shape design to achieve high-frequency broadband electromagnetic shielding. At the same time, the spiral structure can achieve a large ventilation aperture, which improves the poor ventilation performance and poor electromagnetic wave shielding effect of traditional electromagnetic shielding windows. While achieving good ventilation effect, it is convenient to carry out pipeline wiring in the spiral structure. The electromagnetic shielding ventilation device has a wider absorption bandwidth and a high-frequency and efficient electromagnetic wave shielding effect, and is widely used. In summary, the present invention solves the problem that the existing electromagnetic shielding ventilation devices are difficult to achieve high electromagnetic shielding and cannot achieve good ventilation effect.

[0022] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 is a model diagram of an electromagnetic shielding ventilation device provided according to an embodiment of the present invention;

[0025] Figure 2 is a schematic diagram of the front structure of an upper base plate provided according to an embodiment of the present invention;

[0026] Figure 3 is a schematic diagram of the reverse structure of an upper base plate provided according to an embodiment of the present invention;

[0027] Figure 4 is an S parameter curve diagram of an electromagnetic shielding ventilation device provided according to an embodiment of the present invention;

[0028] Figure 5 is an electric field distribution diagram of an electromagnetic shielding ventilation device provided according to an embodiment of the present invention;

[0029] Figure 6 is a diagram showing the effect of the diameter of a ventilation opening on shielding effectiveness provided according to an embodiment of the present invention;

[0030] Figure 7is a diagram showing the effect of the height of a spiral model on shielding effectiveness provided according to an embodiment of the present invention;

[0031] Figure 8 The figure is a diagram showing the influence of the thickness of a spiral model on shielding effectiveness provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0033] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0034] Figure 1 is a model diagram of an electromagnetic shielding ventilation device provided according to an embodiment of the present invention, with reference to Figure 1 An embodiment of the present invention provides an electromagnetic shielding ventilation device, which includes: an upper base plate 10, which is used for total reflection of electromagnetic waves; a lower base plate 20, which is used for ventilation; and an unequally spaced spiral structure 30, which is located between the upper base plate 10 and the lower base plate 20, and is used for reflecting and consuming electromagnetic waves of different frequencies.

[0035] Specifically, the electromagnetic shielding ventilation device comprises three parts, namely, an upper base plate 10, a lower base plate 20 and an unequally spaced spiral structure 30 in the middle, all of which are made of iron. The main body is the unequally spaced spiral structure 30 in the middle layer, which is used to reflect and consume electromagnetic waves of different frequencies.

[0036] The unequally spaced spiral structure 30 can be a spiral electromagnetic shielding structure. The spiral electromagnetic shielding structure can effectively reflect and dissipate electromagnetic waves through its unique spiral shape design, realize high-frequency broadband electromagnetic shielding, and can obtain a larger ventilation aperture while achieving the same frequency shielding performance as similar products. While achieving good ventilation effects, it can facilitate pipeline wiring in the spiral structure.

[0037] The technical solution of the embodiment of the present invention provides an electromagnetic shielding ventilation device with an unequally spaced involute spiral as the structural basis in order to achieve high-frequency electromagnetic shielding with good ventilation performance. The unequally spaced spiral structure can effectively reflect and dissipate electromagnetic waves through the unique spiral shape design to achieve high-frequency broadband electromagnetic shielding. At the same time, the spiral structure can achieve a large ventilation aperture, which improves the poor ventilation performance and poor electromagnetic wave shielding effect of traditional electromagnetic shielding windows. While achieving good ventilation effect, it is convenient to carry out pipeline wiring in the spiral structure. The electromagnetic shielding ventilation device has a wider absorption bandwidth and a high-frequency and efficient electromagnetic wave shielding effect, and is widely used. In summary, the present invention solves the problem that the existing electromagnetic shielding ventilation devices are difficult to achieve high electromagnetic shielding and cannot achieve good ventilation effect.

[0038] Optionally, the unequal-pitch helical structure comprises an unequal-pitch metal involute helical structure.

[0039] Specifically, the main body of the electromagnetic shielding ventilation device adopts an unequally spaced metal involute spiral structure. The metal spiral cavity has a unique geometric shape and electromagnetic properties, which have an important influence on the propagation and reflection of electromagnetic waves. The spiral shape can guide the electromagnetic waves to propagate along a specific path in the cavity, while increasing the number of interactions between the electromagnetic waves and the metal wall, thereby enhancing the reflection and interference effects. When two beams of reflected waves meet in the spiral cavity, if their phase difference is 180° (i.e., half a wavelength), the two beams will cancel each other out, forming a reflection cancellation. At the same time, in the metal spiral cavity, as the number of reflections increases, electromagnetic waves of certain frequencies will gradually be consumed. The design of the unequally spaced involute spiral is to better adapt to electromagnetic waves of different frequencies, which have different wavelengths, propagation speeds and energy distributions, and therefore, they exhibit different behavioral characteristics when interacting with the spiral structure. The design of the unequally spaced involute spiral allows each part of the spiral to have different spacing or pitches, and this non-uniformity enables the spiral structure to produce stronger interactions with electromagnetic waves within a specific frequency range. By adjusting the spacing distribution of the spirals, the selectivity and reflection of electromagnetic waves of different frequencies can be achieved, thereby improving the frequency response characteristics of the device or system. Non-uniformity can also broaden its working bandwidth to a certain extent.

[0040] The unequal-pitch metal involute spiral structure has unique advantages in the design of electromagnetic shielding ventilation devices. It can change the phase of the reflected wave by adjusting the spiral pitch, thereby achieving a more accurate reflection destructive effect. This process requires an in-depth analysis of the propagation characteristics of electromagnetic waves, the geometric parameters of the spiral structure, and the interaction between them. It is necessary to focus on the radius of the unequal-pitch involute spiral, the adjustment of the spiral pitch, and the selection of the number of spiral turns. The radius of the unequal-pitch involute spiral should gradually change with the extension of the spiral to change the path length of the reflected wave and then adjust the phase of the reflected wave. Through mathematical models or simulation software, the influence of different radius change rates on the phase of the reflected wave can be calculated. The spacing between spirals is one of the key factors in controlling the phase of the reflected wave. By adjusting the spacing, the phase difference between the reflected wave and the incident wave can be accurately controlled to achieve the purpose of destructiveness. The adjustment of the spacing should be accurately calculated based on the wavelength and frequency of the electromagnetic wave. The number of spiral turns will also affect the reflection and transmission characteristics of the electromagnetic wave. Properly increasing the number of turns can enhance the reflection effect, but it will also increase the ventilation resistance. Therefore, it is necessary to reasonably determine the number of spiral turns while ensuring the electromagnetic shielding effect. According to the simulation and experimental results, the geometric parameters of the unequal-pitch metal involute spiral structure are further optimized and improved. For example, the radius change rate, spacing, number of turns and other parameters of the spiral are adjusted to improve the balance between electromagnetic shielding effect and ventilation efficiency. The unequal-pitch metal involute spiral can be drawn in two dimensions using the equation of the Archimedean spiral. The parameter equation of the Archimedean spiral is as follows:

[0041]

[0042] Among them, parameter a controls the radius of the spiral, parameter b controls the growth rate of the radius as the spiral increases with time t, and parameter c controls the degree of unequal spacing of the spiral. By adjusting the three parameters, an ideal spiral model can be achieved.

[0043] Optionally, the upper base plate, the lower base plate and the unequally spaced spiral structure are all made of iron.

[0044] Optionally, the lower base plate and the unequally spaced spiral structure are integrally formed.

[0045] Figure 2 is a schematic diagram of the front structure of an upper base plate provided according to an embodiment of the present invention, Figure 3 is a schematic diagram of the reverse structure of an upper base plate provided according to an embodiment of the present invention, with reference to Figure 2 and Figure 3 Optionally, the size of the upper base plate 10 includes 110 mm×110 mm, and the thickness of the upper base plate 10 includes 5 mm.

[0046] Continue to refer Figure 1 and Figure 3Optionally, a spiral groove 11 is provided on the back of the upper base plate 10 ; the upper base plate 10 and the unequally spaced spiral structure 30 are embedded through the spiral groove 11 .

[0047] Specifically, the size of the upper base plate 10 can be 110mm×110mm, and the thickness can be 5mm. The electromagnetic shielding ventilation device is a spiral structure of an open combined installation structure. The lower base plate 20 and the unequally spaced spiral structure 30 are integrally processed and formed, with an openable upper base plate 10, and the upper base plate 10 and the unequally spaced spiral structure 30 below are embedded through a spiral groove 11. A conductive film is laid in the spiral groove 11, and through the combination of screws, wiring can be conveniently performed in the unequally spaced spiral structure 30, which meets the requirements of shielding the routing of communication harnesses between the inside and the outside during construction, and avoids a series of difficulties caused by the small aperture when threading wires in the ventilation duct.

[0048] Continue to refer Figure 3 Optionally, the width of the spiral groove 11 is 5 mm, and the depth of the spiral groove 11 is 2.5 mm.

[0049] Specifically, the upper base plate 10 is composed of a countersunk screw hole and a spiral groove 11 on the back, the width of the spiral groove 11 may be 5 mm, and the depth of the spiral groove 11 may be 2.5 mm. The upper base plate 10 is used for total reflection of electromagnetic waves.

[0050] Continue to refer Figure 1 and Figure 3 Optionally, a first countersunk screw hole 12 is provided on the spiral groove 11, and a second countersunk screw hole 31 is provided on the unequally spaced spiral structure 30, and the positions of the first countersunk screw hole 12 and the second countersunk screw hole 31 correspond to each other.

[0051] Continue to refer Figure 1 and Figure 3 Optionally, the diameter of the first countersunk screw hole 12 includes 3.8 mm, and the depth of the first countersunk screw hole 12 includes 3 mm; the diameter of the second countersunk screw hole 31 includes 3.8 mm, and the depth of the second countersunk screw hole 31 includes 3 mm.

[0052] Specifically, for ease of installation and use, countersunk screw holes are respectively provided on the spiral groove 11 on the back of the upper base plate 10 and the unequally spaced spiral structure 30. The diameter of the countersunk screw hole may be 3.8 mm, and the depth of the countersunk screw hole may be 3 mm.

[0053] Continue to refer Figure 1 Optionally, a vent 21 is provided on the lower base plate 20, and the diameter of the vent 21 is 20 mm.

[0054] Specifically, the lower base plate 20 is provided with a large-diameter vent, the diameter of which may be 20 mm, thereby achieving a good ventilation effect.

[0055] Electronic equipment requires good ventilation and heat dissipation during operation, but traditional electromagnetic shielding structures often limit the size of the vents in order to achieve shielding of high-frequency electromagnetic screens, affecting the heat dissipation effect. The present invention adopts an upper base plate based on an unequally spaced involute spiral structure design, so that the ventilation aperture can be increased while maintaining the electromagnetic shielding effectiveness. Through precise calculation and optimized design, it is ensured that the increase in the ventilation aperture will not significantly reduce the electromagnetic shielding effect.

[0056] With the widespread application of high-frequency electromagnetic waves, traditional electromagnetic shielding structures are difficult to meet the electromagnetic wave shielding of high-frequency broadband, resulting in leakage of electromagnetic waves. In order to solve this problem, the present invention innovatively designs a high-efficiency electromagnetic shielding ventilation device with an unequally spaced involute spiral structure as the core, which can achieve 0-20GHz broadband high-frequency electromagnetic wave shielding. By adopting a spiral structure, the spiral structure precisely controls the interaction between the spiral path and the electromagnetic wave, and utilizes the phase difference of the reflected wave to cancel the incident wave. At the same time, the design of the unequally spaced involute spiral allows each part of the spiral to have a different spacing or pitch, and this non-uniformity enables the spiral structure to produce a stronger interaction with electromagnetic waves within a specific frequency range. By adjusting the spacing distribution of the spiral, selectivity and reflection of electromagnetic waves of different frequencies can be achieved, thereby improving the frequency response characteristics of the device or system. Non-uniformity also broadens its working bandwidth to a certain extent.

[0057] In summary, the electromagnetic shielding ventilation device in the present invention not only has high-frequency broadband electromagnetic shielding effectiveness, but also improves the problem of poor ventilation effect of existing waveguide windows. When achieving the same shielding frequency band range, it can have a larger ventilation aperture, which greatly improves the ventilation efficiency. The overall structure of the open combined installation structure, the lower base plate and the spiral structure are integrally processed and formed, and it has an openable upper base plate, which is conducive to the routing of communication cables in the subsequent construction process and has a wider application. The electromagnetic shielding ventilation device can achieve a vent diameter of 20mm when achieving a shielding effectiveness of 20GHz, which is much higher than the existing honeycomb waveguide structure, which has a vent diameter of only 3mm when achieving a shielding effectiveness of 20GHz.

[0058] In order to verify the electromagnetic shielding effectiveness of the electromagnetic shielding ventilation device, the proposed spiral model was modeled and data analyzed. The spiral model was placed in a spatial plane, the point with the maximum electromagnetic wave radiation was selected as the electromagnetic wave incident direction, and the vent was selected as the electromagnetic wave receiving position to simulate the worst shielding performance. Figure 4 is an S parameter curve diagram of an electromagnetic shielding ventilation device provided according to an embodiment of the present invention, with reference to Figure 4 , S21 curve ( Figure 4) characterizes the leakage of electromagnetic waves. In the range of 0-18GHz, the S21 curve values ​​are all below -40dB, which means that the electromagnetic shielding effectiveness can reach 99%. In the range of 0-20GHz, the entire curve is below -20dB, which means 90% electromagnetic shielding effectiveness.

[0059] Figure 5 is an electric field distribution diagram of an electromagnetic shielding ventilation device provided according to an embodiment of the present invention, Figure 5 (a) is the electric field distribution at 5 GHz, (b) is the electric field distribution at 10 GHz, (c) is the electric field distribution at 15 GHz, and (d) is the electric field distribution at 20 GHz. Figure 5 ), the propagation path of the electromagnetic wave can be clearly seen. In the absence of a shielding structure, the electromagnetic wave will propagate along a straight line or refract according to the characteristics of the medium. However, in the presence of a shielding structure, the propagation path of the electromagnetic wave will zigzag along the spiral structure, changing its original propagation direction and not reaching the vent at the end of the spiral. The results show that the ventilated shielding structure can achieve high-frequency broadband electromagnetic shielding of 0-20GHz.

[0060] In order to achieve good ventilation performance, vents of different sizes are simulated to evaluate their impact on the indoor airflow pattern, so as to select the optimal vent size to achieve better ventilation effect and indoor air quality. The original vent with a diameter of 20mm is adjusted to 30mm and 40mm, and their electromagnetic shielding effectiveness is compared. Figure 6 is a diagram showing the effect of the vent diameter on shielding effectiveness according to an embodiment of the present invention, referring to Figure 6 ,from Figure 6 It can be seen that in the range of 0-12GHz, the size of the vent has a greater impact on the shielding effectiveness. Specifically, as the size of the vent increases, the electromagnetic shielding effectiveness decreases. In the range of 12-20GHz, the size of the vent has a smaller impact on the electromagnetic shielding effect. The shielding effect of a 20mm vent is the best.

[0061] Figure 7 is a diagram showing the effect of the height of a spiral model on shielding effectiveness provided according to an embodiment of the present invention. Figure 8 is a diagram showing the effect of spiral model thickness on shielding effectiveness according to an embodiment of the present invention, with reference to Figure 7 and Figure 8 In order to adapt to the different requirements of the process and different application scenarios for the spiral structure, the simulation analysis of the performance of spiral structures of different heights and thicknesses under different conditions can provide designers with more options and improve design flexibility. The simulation results are as follows Figure 7 , Figure 8As shown, it can be clearly seen that the thickness and height of the spiral model have no significant effect on the electromagnetic shielding effectiveness.

[0062] In summary, the present invention adopts an unequally spaced spiral structure, and this design exhibits excellent electromagnetic wave shielding capabilities in a wide frequency range (such as 0-20GHz). The design of the unequally spaced spiral allows each part of the spiral to have different spacing or pitches, and this non-uniformity enables the spiral structure to produce stronger interactions with electromagnetic waves within a specific frequency range. By adjusting the spacing distribution of the spiral, selectivity and reflection of electromagnetic waves of different frequencies can be achieved, thereby improving the frequency response characteristics of the device or system. Non-uniformity also broadens its operating bandwidth to a certain extent. Thereby reducing electromagnetic leakage and ensuring efficient electromagnetic shielding effect. The design of the ventilation structure not only takes into account electromagnetic shielding, but also takes into account the needs of ventilation and heat dissipation. Through reasonable spiral arrangement and ventilation duct design, good air circulation is achieved, which helps to reduce the internal temperature of the equipment and ensure electromagnetic information security.

[0063] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An electromagnetic shielding ventilation device, characterized in that: include: An upper base plate, the upper base plate is used for total reflection of electromagnetic waves; A lower bottom plate, the lower bottom plate is used for ventilation; An unequal-pitch spiral structure, wherein the unequal-pitch spiral structure is located between the upper base plate and the lower base plate, and is used for reflecting and consuming electromagnetic waves of different frequencies.

2. The electromagnetic shielding ventilation device according to claim 1, characterized in that: The unequal-pitch helical structure comprises an unequal-pitch metal involute helical structure.

3. The electromagnetic shielding ventilation device according to claim 1, characterized in that: The upper base plate, the lower base plate and the unequally spaced spiral structure are all made of iron.

4. The electromagnetic shielding ventilation device according to claim 1, characterized in that: The lower base plate and the unequal-distance spiral structure are integrally formed.

5. The electromagnetic shielding ventilation device according to claim 1, characterized in that: The size of the upper base plate includes 110 mm×110 mm, and the thickness of the upper base plate includes 5 mm.

6. The electromagnetic shielding ventilation device according to claim 1, characterized in that: A spiral groove is provided on the back side of the upper base plate; The upper base plate and the unequally spaced spiral structure are embedded through the spiral groove.

7. The electromagnetic shielding ventilation device according to claim 6, characterized in that: The width of the spiral groove is 5 mm, and the depth of the spiral groove is 2.5 mm.

8. The electromagnetic shielding ventilation device according to claim 6, characterized in that: A first countersunk screw hole is arranged on the spiral groove, and a second countersunk screw hole is arranged on the unequally spaced spiral structure, and the positions of the first countersunk screw hole and the second countersunk screw hole correspond to each other.

9. The electromagnetic shielding ventilation device according to claim 8, characterized in that: The diameter of the first countersunk screw hole comprises 3.8 mm, and the depth of the first countersunk screw hole comprises 3 mm; A diameter of the second countersunk screw hole comprises 3.8 mm, and a depth of the second countersunk screw hole comprises 3 mm.

10. The electromagnetic shielding ventilation device according to claim 1, characterized in that: A vent is provided on the lower base plate, and the diameter of the vent is 20 mm.

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