JP2002134977A - Electromagnetic wave shield box and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic wave shield box which has enough tolerance and functions to eliminate the influence of an electromagnetic wave on its stored electronic equipment and makes the generated electromagnetic wave not to flow out. SOLUTION: This is a plastic box which contains or covers the electronic equipment such as a computer, and an electromagnetic wave shield material is made by insert molding as an intermediate layer with a box wall. An earth part which is connected to the electromagnetic shield material and an adapter which connects the internal electronic equipment are provided on the external surface of the box. Consequently, the electromagnetic wave shield box which has enough tolerance and functions to eliminate the influence of the external electromagnetic wave on the stored electronic equipment and makes the generated electromagnetic wave not to flow out, and its manufacturing method are successfully provided, the box can freely be molded adaptively to various electronic equipment and their shapes and structures, and the manufacturing is easy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic wave shielding box for housing a computer to protect the computer from electromagnetic waves and prevent malfunction, and a method of manufacturing the same.

[0002]

2. Description of the Related Art With the development of various computer-related technologies, these devices have been recently affected by mutual interference due to the close arrangement of the devices, which causes malfunction. For electronic equipment used in such an electromagnetic environment, measures must be taken to prevent interference even if electromagnetic interference waves arrive, and to prevent the generation of electromagnetic interference waves that may affect other electronic equipment. Two environmental conditions (called electromagnetic compatibility) are important.

[0003] In addition, there are obstacles due to communication radio waves (especially recently due to the use of mobile phones), electromagnetic waves from automobile engines and engine peripherals, fundamental waves of power lines, and the like. Electromagnetic waves associated with natural phenomena such as fluctuations and lightning strikes cannot be overlooked.

As a countermeasure against electromagnetic wave interference, electromagnetic wave shielding materials or components have conventionally been used, and there are many types of such materials, which protect electronic components or electronic circuits or prevent generated noise from leaking out. In order to do so, it is widely applied to attach a noise filter, a noise prevention capacitor, a shield cover, and the like.

[0005] The term "electromagnetic wave shielding material" refers to a material that does not allow electromagnetic interference waves to pass therethrough. For example, a metal that does not allow electromagnetic interference waves to pass through is a typical example of an electromagnetic wave shielding material. Also,
Conductive film (resistance film), conductive composite material (conductive rubber,
(Conductive plastic), a conductive surface-treated product, a conductive adhesive, and the like.

[0006]

However, it is difficult to use these electromagnetic wave shielding materials in accordance with the shapes and structures of various electronic devices, and the electromagnetic wave shielding effect has not been sufficiently improved. In addition, to rubber and plastic,
A conductive composite material mixed with metal or carbon particles and flakes and fibers has an advantage that molding is easy, but a shielding effect cannot be obtained unless a sufficient amount of conductive material is mixed, and If the mixing ratio is less than the above value, the shielding effect sharply decreases. Therefore, in order to obtain a desired shielding effect, it is necessary to sacrifice the strength of the molded body.

The present invention has been made in view of the above-described circumstances,
It is an object of the present invention to provide an electromagnetic wave shielding box and a method of manufacturing the same that have sufficient strength and function so that the housed electronic device is not affected by external electromagnetic waves and does not allow the generated electromagnetic waves to flow outside. .

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an electromagnetic wave shielding box according to the present invention. As the electromagnetic wave shielding material, a net-like material is preferable (claim 2). Further, a method for manufacturing an electromagnetic wave shielding box is configured as in claim 3.

[0009]

In the above construction, the electromagnetic wave shielding material covering the internal electronic device is compounded as an intermediate layer of the box wall, but the inside of the wall and the outside of the wall sandwiching the electromagnetic wave shielding material are integrated through a mesh. Therefore, breakage and corrosion are prevented, and the strength of the electromagnetic wave shielding material is maintained.

That is, if there is no mesh hole in the shield material, the resin is divided into an inner wall portion and an outer wall portion by the shield material when insert-molding the shield material in resin (plastic). In the insert molding according to the above, since the resin penetrates through the mesh holes of the shield material and the inner wall portion and the outer wall portion are integrated, the above-described division is prevented, and the durability and reliability of the product are improved. This can significantly improve the performance.

Further, since the electromagnetic wave absorbed by the electromagnetic wave shielding material is radiated from the ground portion to the outside, the electromagnetic wave does not accumulate inside, and the proof strength and function are maintained in this respect, too. Thus, the internal electronic device is safely protected, and adverse effects on the external electronic device are also prevented.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, an electromagnetic wave shielding material 3 refers to a material that does not allow electromagnetic interference to pass therethrough.
Metals such as aluminum, iron and metal alloys are typical, but non-metallic materials such as conductive rubber and conductive plastics may also be used. Further, the term “net-like” refers to a porous type or a mesh type such as a wire net, a honeycomb (honeycomb), a punched metal, an expanded metal, and the like. Further, depending on the case, a plate (plate) -shaped electromagnetic wave shielding material may be used instead of a net-like shape. In this case,
It is preferable that the plate be provided with several through-holes so that the resin flows into the holes and integrates the plate and the resin.

Further, the composite of the electromagnetic wave shielding material 3 is not limited to a single layer, but may be a multilayer. Regarding this point, copper and aluminum have a small resistivity and therefore have a large shielding effect, but they have no magnetic field shielding effect. Therefore, they may be used in combination with a magnetic shielding material such as iron or ferrite. Even in this case, the box can be freely and easily formed by insert molding.

Further, input and output of electric and electronic signals to and from a control device and a computer in the box are performed through a connector. Therefore, if necessary, the connector part is attached as a separate body or is attached as an integral part of insert molding. For grounding and required equipment,
The box is provided with a grounding part to enable connection with the outside.

An arbitrary shape is adopted as the shape of the box. Then, there are methods such as storing a plurality of devices in this box, or storing automobile ignition system devices (for example, ignition coils) one by one individually.
It is possible to arbitrarily set a shape that is easy to make and saves the most cost according to the product shape to be stored.

[0016]

As described above, according to the present invention, the stored electronic device is not affected by external electromagnetic waves, and has a sufficient strength and function to prevent the generated electromagnetic waves from flowing out. It has succeeded in providing such an electromagnetic wave shielding box and a method for manufacturing the same, and is excellent in that the box can be freely formed in accordance with various electronic devices and their shapes and structures, and the manufacturing is easy. effective.

[0017]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show an embodiment, in which an electromagnetic wave shielding box B comprises a plastic body 1 and a lid 2, and the body 1 and the lid 2 are provided with an electromagnetic wave shielding material 3 respectively. The grounding portions 5 and 6 of the electromagnetic wave shielding material 3 are exposed on the upper and lower ends of the body 1 and the upper and lower surfaces of the lid 2 and are integrated into the wall layer by mold insert molding. Several connectors 9 having a plurality of terminals are attached for electrical connection with the connector.

A wire mesh is used for the electromagnetic wave shielding material 3,
The body 1 is put into each side wall and the bottom wall by assembling the wire mesh into a box shape, and the ground portion 5 is formed by bent pieces at the upper and lower ends. Further, the electromagnetic wave shielding material 3 is put into the lid 2 by a single net, and an earth part 6 connected to the earth part 5 of the body 1 is formed on the lower surface, and a discharge earth part 5 is formed by a bent piece on the upper surface. ing. Then, the plastic material flows into the mesh 7 by insert molding, and the inside 8a of the wall and the outside 8b of the wall sandwiching the wire mesh are integrated via the mesh 7.

As for the use of the electromagnetic wave shielding box B, for example, a high-performance computer is housed and connected to an external device via the connector 9 to control the computer from the outside and obtain its output.

FIG. 3 shows another embodiment, in which the above-described embodiment has a round shape instead of a square shape, but has substantially the same configuration. In this case, as the electromagnetic wave shielding material 3, for example, a metal mesh plate called a punching metal in which a number of holes are formed in a thin iron plate is used, and the electromagnetic wave shielding material 3 of the body 1 and the electromagnetic wave shielding material 3 of the lid 2 are different from each other. It is connected by a difference pin for stopping the lid 2, and the head of the difference pin also serves as the ground part 5.

FIGS. 4 and 5 show other embodiments, respectively. FIG. 4 shows an automobile engine cover as shown in FIG.
In the figure, an electromagnetic wave shielding box B is configured as an automobile ignition coil exterior, and a net-shaped electromagnetic wave shielding material 3 is compounded by insert molding.

[Brief description of the drawings]

FIG. 1 is a cutaway perspective view showing an electromagnetic wave shield box according to the present invention.

FIG. 2 is an enlarged sectional view taken along line XX of FIG.

FIG. 3 is a cutaway perspective view showing an electromagnetic wave shielding box according to another embodiment.

FIG. 4 is a cutaway perspective view showing an electromagnetic wave shielding box according to another embodiment.

FIG. 5 is a cutaway perspective view showing an electromagnetic wave shielding box according to another embodiment.

[Explanation of symbols]

 B Electromagnetic wave shielding box 3 Electromagnetic wave shielding material 5, 6 Ground part 7 Mesh 8a Inside wall 8b Outside wall 9 Connector

Claims (3)

[Claims] 1. A plastic box for housing or covering an electronic device such as a computer, wherein an electromagnetic wave shielding material is integrated and integrated as an intermediate layer on a box wall by insert molding, and an electromagnetic wave shielding material is formed on an outer surface of the box. An electromagnetic wave shield box, comprising: a ground portion connected to the electronic device; and an adapter connecting the internal electronic device. 2. The electromagnetic wave shielding box according to claim 1, wherein the electromagnetic wave shielding material is in a net shape. 3. In the manufacture of a plastic box for housing or covering an electronic device such as a computer,
A method of manufacturing an electromagnetic wave shielding box, comprising: combining a net-like electromagnetic wave shielding material as an intermediate layer on a box wall by insert molding; and integrating the inside of the wall and the outside of the wall through a mesh.