CN108366518B

CN108366518B - Metal shielding box

Info

Publication number: CN108366518B
Application number: CN201810090045.0A
Authority: CN
Inventors: 金志虎; 汪澜; 龚谱升; 王宏
Original assignee: Shenzhen Gongjin Electronics Co Ltd
Current assignee: Shenzhen Gongjin Electronics Co Ltd
Priority date: 2018-01-30
Filing date: 2018-01-30
Publication date: 2020-10-27
Anticipated expiration: 2038-01-30
Also published as: CN108366518A

Abstract

The invention is suitable for the technical field of electronic product production test, and provides a metal shielding box which comprises a shielding box body provided with an accommodating cavity, wherein at least one corner reflector is arranged on the side wall of the accommodating cavity, and a triangular metal plate for destroying the cavity reflection of the corner reflector is arranged at the end point of the corner reflector. According to the invention, the triangular metal plate for destroying the cavity reflection of the corner reflector is arranged at the end point of the corner reflector, so that the metal shielding box can effectively isolate the wireless radiation source and can effectively cover the communication frequency band of the common radio frequency electronic equipment.

Description

Metal shielding box

Technical Field

The invention belongs to the technical field of electronic product production test, and particularly relates to a metal shielding box.

Background

In the prior art, many electronic products or toys have functions of wireless connection and the like. Since there is a lot of radio signal interference in the air and as the technology improves, both the wireless transmitting power and the receiving power are reduced, a shielding box is needed to shield the interference of radio frequency to the product in the test.

With the reduction of the received power of electronic products and the exponential increase of wireless radiation sources in the external environment, it has been difficult for the conventional metal shielding box to effectively isolate the wireless radiation sources or effectively shield the radiation in the shielding box.

Disclosure of Invention

The invention aims to provide a metal shielding box, and aims to solve the technical problem that a traditional metal shielding box is difficult to effectively isolate a wireless radiation source.

The invention is realized in such a way that the metal shielding box comprises a shielding box body provided with an accommodating cavity, wherein the side wall of the accommodating cavity is provided with at least one corner reflector, and the end point of the corner reflector is provided with a triangular metal plate for destroying the cavity reflection of the corner reflector.

Further, the cross section of the triangular metal plate is in an equilateral triangle shape.

Furthermore, the shielding box body comprises three quadrilateral metal plates, one end of each quadrilateral metal plate is respectively connected with one side of the triangular metal plate.

Further, the cross section of the quadrilateral metal plate is square or rectangular.

Furthermore, the side length of the triangular metal plate is greater than or equal to 12cm, and the thickness of the triangular metal plate is greater than or equal to 3 cm.

Furthermore, a powder pressing ferrite plate is laid on the side wall of the containing cavity, and the powder granularity of the ferrite plate is 10 mu m to 3 nm.

Further, edge intersection of 45 degrees or 135 degrees is adopted between adjacent ferrite plates.

Further, the thickness of the ferrite plate is 5mm to 15 mm.

Furthermore, an inclined hole with a normal inclination angle of more than or equal to 60 degrees is formed in the ferrite plate.

Furthermore, a wave absorbing layer with the thickness of 5mm to 9mm is laid on the ferrite plate.

The metal shielding box has the following beneficial effects: compared with the prior art, the triangular metal plate for destroying the cavity reflection of the corner reflector is arranged at the end point of the corner reflector, so that the metal shielding box can effectively isolate the wireless radiation source and can effectively cover the communication frequency band of the common radio frequency electronic equipment.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a metal shielding box according to an embodiment of the present invention.

Reference numerals referred to in the above figures are detailed below:

1-shielding box body; 11-triangular metal plate; 12-quadrilateral metal sheet.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly or indirectly secured to the other element. When an element is referred to as being "connected to" another element, it can be directly or indirectly connected to the other element.

The terms "upper", "lower", "left", "right", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description, but do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the patent. The terms "first", "second" and "first" are used merely for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features. The meaning of "plurality" is two or more unless specifically limited otherwise.

As shown in fig. 1, the metal shielding box provided by the embodiment of the present invention includes a shielding box body 1 having a receiving cavity, at least one corner reflector is disposed on a sidewall of the receiving cavity, and a triangular metal plate 11 for destroying a cavity reflection of the corner reflector is disposed on an end point of the corner reflector. In the embodiment of the invention, the triangular metal plate 11 is adopted for effective isolation of the common radio frequency shielding box, so that the low-cost shielding box reaches the isolation degree of a high-quality shielding box, but the transformation cost price is less than 3000 yuan, and the transformed metal shielding box can effectively cover the communication frequency band (15 MHz-6 GHz) of the common radio frequency electronic equipment.

Compared with the prior art, the triangular metal plate 11 for destroying the cavity reflection of the corner reflector is arranged at the end point of the corner reflector, so that the metal shielding box can effectively isolate the wireless radiation source or effectively shield the radiation in the shielding box.

Further, in one embodiment of the present invention, four corner reflectors are disposed on the side wall of the accommodating cavity, and the corner reflectors refer to three metal planes which are perpendicular to each other, and such planes can produce strong multipath phase difference transmission inside the shielding box, so that the receiving-end antenna suffers from phase difference interference. The multipath effect means that after electromagnetic waves are propagated through different paths, the time for each component field to reach a receiving end is different, and the component fields are mutually superposed according to respective phases to cause interference, so that the original signal is distorted or an error is generated. For example, electromagnetic waves propagate along two different paths, and the lengths of the two paths are different by exactly half a wavelength, so that the two paths of signals exactly cancel each other when reaching the end point (the peak and the trough coincide), resulting in measurement misalignment. In order to avoid this, in the present embodiment, a triangular metal plate 11 is provided at an end point of each corner reflector, wherein an example in which only the triangular metal plate 11 is provided at an end point of one of the corner reflectors is given in fig. 1.

Further, in one embodiment of the present invention, the triangular metal plate 11 has an equilateral triangle cross section so that the triangular metal plate 11 uniformly destroys the cavity reflection of the corner reflector. Preferably, in this embodiment, the side length of the triangular metal plate 11 is greater than or equal to 12cm, the thickness of the triangular metal plate 11 is greater than or equal to 3cm, and the triangular metal plate 11 is attached to and placed at the end point of each corner reflector.

Further, in one embodiment of the present invention, the shielded box body 1 includes three quadrangular metal plates 12 having one ends respectively connected to one side of the triangular metal plate 11. Specifically, one end of three quadrangular metal plates 12 is welded to three sides of the triangular metal plate 11, respectively, and the quadrangular metal plates 12 are used to break a right angle in the shielded box body 1, which breaks a corner reflector structure together with the triangular metal plate 11. Preferably, in the present embodiment, the cross section of the quadrilateral metal plate 12 is square or rectangular. Further preferably, the quadrangular metal plate 12 is an iron plate.

Further, in one embodiment of the present invention, a powder laminated ferrite plate having a powder particle size of 10 μm to 3nm is laid on the side wall of the receiving cavity, and the powder laminated ferrite plate can effectively transmit and absorb electromagnetic radiation. Preferably, in the present embodiment, 45 ° or 135 ° edge intersection is used between adjacent ferrite slabs. Further preferably, the thickness of the ferrite plate is 5mm to 15mm, so that the ferrite plate is not too thick to seriously occupy the effective use space in the box body.

Further, in an embodiment of the present invention, the ferrite plate is provided with an oblique opening with a normal inclination angle of 60 ° or more, and the opening is a smooth aperture, so as to avoid the occurrence of a right-angled edge or contour.

Further, in one embodiment of the invention, a wave absorbing layer with the thickness of 5mm to 9mm is laid on the ferrite plate, and the wave absorbing layer is used for converting the radiation electromagnetic wave energy of the communication signal into heat energy. Preferably, in this embodiment, the wave-absorbing layer is a low-density ferrite powder-colloid shielding layer, the overlap ratio at the joint is greater than 5cm, the joints of any two layers of materials are not overlapped as much as possible, and the contour of each ferrite plate is a non-right-angled sawtooth.

Further, in one embodiment of the present invention, a low-density ferrite powder-colloid shielding layer of 1mm to 5mm may be laid outside the shielding box.

In summary, the overall modification cost of the metal shielding box in the embodiment of the invention is not more than 2000 yuan, and the total cost of 2000 yuan of the original existing box body is not more than 5000 yuan, but the use effect can be comparable to 20000 yuan of high-end shielding box products in the market. Specifically, the metal shielding box provided by the embodiment of the invention can effectively improve the internal isolation of the shielding box by 20db, and can realize high isolation larger than 70db by matching with the isolation of 60db in the original metal shielding box, and can effectively reduce the electromagnetic reflection in the shielding box.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A metal shielding box is characterized by comprising a shielding box body provided with an accommodating cavity, wherein at least one corner reflector is formed on the side wall of the accommodating cavity, and a triangular metal plate for destroying the cavity reflection of the corner reflector is arranged at the end point of the corner reflector, so that the metal shielding box can effectively isolate a wireless radiation source in the external environment or effectively shield the radiation in the shielding box, and the cross section of the triangular metal plate is in an equilateral triangle shape; wherein the end points of the corner reflectors are located at the intersection of three planes perpendicular to each other.

2. The metallic shielding cage according to claim 1, wherein said cage body comprises three quadrangular metallic plates having one ends respectively connected to one of sides of said triangular metallic plates.

3. The metallic shielding cage according to claim 2, wherein said quadrilateral metallic plate has a square or rectangular cross-section.

4. The metallic shielding box according to claim 1, wherein the side length of said triangular metallic plate is 12cm or more, and the thickness of said triangular metallic plate is 3cm or more.

5. The metallic shielding box of any one of claims 1 to 4, wherein a powder pressed ferrite plate is laid on the side wall of the accommodating cavity, and the powder particle size of the ferrite plate is 10 μm to 3 nm.

6. The metallic shielding cage as set forth in claim 5, wherein adjacent ones of said ferrite plates meet at 45 ° or 135 ° edges.

7. The metallic shielding cage as set forth in claim 5, wherein said ferrite plate has a thickness of 5mm to 15 mm.

8. The metal shielding case of claim 5, wherein said ferrite plate has an inclined opening with a normal inclination of 60 ° or more.

9. The metal shielding box of claim 5, wherein the ferrite plate is coated with a wave-absorbing layer with a thickness of 5mm to 9 mm.