JPH04133497U - Electromagnetic shielding materials - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an electromagnetic shielding member that can eliminate gaps even in the case of a weak pressing force in a housing for storing electronic components, thereby providing sufficient electromagnetic shielding. thing. [Configuration] Attached to the opening/closing part of the housing 3, etc.
An electromagnetic shielding gasket 1 that shields electromagnetic waves from a gap includes a cylindrical member 20 made of conductive silicone or the like, and a fixing recess 2 inserted inside the cylindrical member 20.
2b, and a stopper 22a provided at the inner end of the fixing recess 22b to prevent the cylindrical member 20 from being compressed beyond a certain level.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is an electromagnetic wave shielding gasket that shields electronic components from electromagnetic waves. The present invention relates to a magnetic wave shielding member.

0002

[Prior art]

In recent years, various devices using electronic components such as microcomputers, such as electronic Office machines such as lighters and printers, household electrical equipment such as washing machines and vacuum cleaners, or combustion 2. Description of the Related Art Automobiles that electronically control fuel injection, etc. are rapidly becoming popular. and used The number of microcomputers is also increasing, and with it, the clock frequency is increasing. is being developed.

0003 However, due to this higher frequency, electromagnetic noise generated by electronic components, etc. Surrounding signals are emitted from gaps in opening/closing parts, joints, etc. of the housing that houses each electronic component. It may get on wires or act directly on electronic components, causing malfunctions such as failures and malfunctions of electronic components. This may occur. Furthermore, magnetic recording elements in electronic components emit small magnetic energy. Because it is made by magnetizing a magnetic material with high density, it will not be affected by external magnetic fields caused by electromagnets, etc. This can lead to negative effects such as loss of recorded information.

0004 In order to prevent interference caused by such electromagnetic waves, conventional methods have been used, such as using highly conductive metal particles. Or electromagnetic shielding gas made of elastomer containing carbon black particles A gasket (hereinafter referred to as an elastomer gasket) is loaded into the gap in the housing.

[0005]

[Problem that the idea aims to solve]

However, if an elastomer gasket like the one described above is used in a housing, etc. In some cases, the electromagnetic wave shielding properties of the housing are not necessarily sufficient, and the following issues remain. There is.

[0006] Elastomer gaskets contain highly conductive metal particles or carbon black particles. The high conductivity imparted by particles (hereinafter referred to as conductive particles) and the elastomer base material Equipped with Toma's own elasticity. However, with increasing content of conductive particles, On the other hand, if the content of conductive particles exceeds a certain value, errors may occur. The elasticity of the stoma itself is impaired. Therefore, the content of conductive particles remains constant. Although it is limited to the upper limit, a decrease in elasticity is still unavoidable.

[0007] Therefore, for example, if the pressure applied to the opening/closing part of the casing is small, the lid will be covered with elastomer gas. The gasket could not be compressed sufficiently, and the gap between the elastomer gasket and the lid There were times when a gap was created. As a result, sufficient electromagnetic shielding may not be possible. There was a problem.

[0008] This invention was made to solve the above problems, and its purpose is to store electronic components. It is possible to eliminate gaps even in the case of a weak pressing force, thereby An object of the present invention is to provide an electromagnetic shielding member that can provide sufficient electromagnetic shielding. That is.

[0009]

[Means to solve the problem]

The present invention was developed to achieve this purpose. Used where multiple members come into contact to shield electromagnetic waves passing between the members. In electromagnetic shielding members, an elastic cylindrical member having at least a conductive surface; a solder fixing recess, and a solder fixing recess provided at the inner end of the fixing recess, which An electromagnetic shielding member characterized by having a stopper that prevents compression. This is the summary.

0010 Here, the electromagnetic wave shielding member refers to, for example, the part that protects electromagnetic waves from opening and closing parts and gaps in the housing. This is a member such as a gasket for electromagnetic shielding used for shielding. As the cylindrical member, for example, conductive silicone can be used, or rubber or the like can be used. Conductive materials such as wire mesh may be overknitted on the surface of the elastomer. . In addition, the shape of the cylindrical member may be circular in cross section, or polygonal such as triangular or square. etc. can be adopted. In addition, the through hole of the cylindrical member should be filled with flexible sponge foam or fiber. etc. may be placed.

[0011] Furthermore, the shape of the recess may be a substantially U-shape that opens downward, or an inverted trapezoid shape. It is suitable because it can easily fit into the convex part provided on the casing etc. or the end of the plate material, etc. Therefore, it is possible to prevent the cylindrical member from being compressed by, for example, 50% or less.

0012

[Effect]

In the electromagnetic shielding member of the present invention, the fixed recess of the cylindrical member is By fitting into the convex part provided on the closed part, the entire electromagnetic shielding member can be Fix the body to the housing.

[0013] For example, when the lid of the housing is closed, the top of the cylindrical part is pushed by the lid. Pressed and compressed. At this time, the upper part of the pressed cylindrical member is inside the cylindrical member. It hits the stopper of the fixing recess that protrudes to the side and prevents further movement. , compression of the cylindrical member beyond a certain level is prevented. As a result, at least The cylindrical member with a conductive surface contacts the lid over a wide area, so it seals out electromagnetic waves. This will improve the ability to code.

[0014]

【Example】

The following is an implementation in which the electromagnetic shielding member according to the present invention was applied to the opening/closing part of the housing. Let's discuss an example. FIG. 1 shows a case in which the electromagnetic shielding gasket 1 of this embodiment houses electronic components. (Case) 3 is a partially cutaway perspective view showing a state where it is attached.

[0015] Case 3 is made of metal and has a rectangular parallelepiped shape, with an opening to accommodate electronic components. A section 4 is provided. A metal lid 5 is attached to this opening 4 via a hinge 7. It is attached so that it can move freely. Further, a fixing convex portion 10 is formed around the edge 9 of the case 3 that meets the lid 5. As will be described later, an electromagnetic shielding gasket 1 is attached to this fixed protrusion 10. It is attached.

[0016] Furthermore, when the lid body 5 is closed, the electromagnetic shielding gasket 1 is sandwiched between the case and the case. 3 and the lid body 5 are tightened together to seal the inside of the case 3. A body tightening portion 11 is provided on the case 3 and the lid body 5. In addition, the side of case 3 To do this, take out the signal wires (not shown) of the electronic components housed in the case 3 to the outside. A waterproof connector 13 is attached for this purpose.

[0017] The electromagnetic shielding gasket 1 described above is made of elastic conductive silicone. As shown in FIG. , a fitting portion with a height h of 8 mm formed by recessing a part of the cylindrical member 20 toward the through hole 21 side. 22.

[0018] This fitting part 22 has a substantially U-shaped cross section, and a flat stopper 22 is attached to the upper part of the fitting part 22. a and a fixing recess 22b that opens downward in the figure. Also, The height h of the fitting part 22 prevents the upper part 20a of the cylindrical member 20 from descending beyond a certain level. For example, since the diameter of the cylindrical member 20 is set to 1/2, the diameter of the cylindrical member 2 Between the upper part 20a of 0 and the stopper 22a, there is a space 24 for deflection at a predetermined interval. There will be.

[0019] The electromagnetic shielding gasket 1 is formed by extrusion molding, for example. Ru. The electromagnetic shielding gasket 1 having the above configuration is used in the following manner. As shown in FIG. 3(A), the electromagnetic shielding gasket 1 is attached to the edge 9 of the housing 3. The fixing concave portion 22b of the fitting portion 22 is fitted into the formed fixing convex portion 10, Fixed by its own elasticity.

[0020] First, when the lid body 5 is not closed, the cylindrical member 20 is compressed. Therefore, there is a predetermined space (the above-mentioned space) between the upper part 20a of the cylindrical member and the stopper 22a. There is an interval (corresponding to interval 24). Here, when the lid body 5 is closed, the cylindrical member 20 is moved upward and downward, as shown in FIG. 3(B). As it is compressed by being pressed in that direction, it bends downward and expands from side to side. Thereby , the upper part 20a of the cylindrical member 20 hits the stopper 22a, suppressing further descent. Since the lid body 5 is also restrained at the same time, the cylindrical member 20 can be moved within a predetermined range (e.g. It will be stopped in a compressed state up to 50%).

[0021] Note that when the lid body 5 is opened again, the state shown in FIG. 3(A) is reached, and the cylindrical member 2 0 returns to its original state due to its own elasticity. In this way, in the electromagnetic shielding gasket 1 of this embodiment, one part of the cylindrical member 20 is Since the fixing recess 22b that protrudes inward is provided in the Even when the force is small, the cylindrical member 20 easily bends and comes into close contact with the lid body 5 over a wide area. do. As a result, the gap between the lid body 5 and the electromagnetic shielding gasket 1 is completely closed. It can be sealed to provide sufficient electromagnetic shielding.

[0022] Further, the cylindrical member 20 is compressed beyond a certain compression rate by the stopper 22a. Since the cylindrical member 20 is prevented from shrinking, the cylindrical member 20 is prevented from being excessively compressed and damaged. Therefore, when the lid body 5 is opened, it has the advantage of being able to quickly restore its external shape. There is a point.

[0023] Furthermore, the electromagnetic shielding gasket 1 of this embodiment has its fixing recess 22b connected to the housing. It can be fixed to the housing 3 simply by fitting it into the fixing protrusion 10 on the body 3 side, so the installation work is easy. It has the advantage of being extremely easy to use. Next, other embodiments will be described.

[0024] As shown in FIG. 4, the electromagnetic shielding gasket 30 of this embodiment has a fitting portion. The shape of the fixing recess 31b provided in 31 is approximately an inverted trapezoid narrowing downward in the figure, Moreover, the surface of the cylindrical member 33 is covered with a conductive metal mesh 34. Therefore, this electromagnetic shielding gasket 30 can be used, for example, on a plate material constituting the housing. (Fixing convex part) When fitted into the fitting part 35, the tip part 31c of the fitting part 31 is fixed with strong pressing force. Since the fixed convex portion 35 is gripped, it can be firmly attached.

[0025] Then, when the electromagnetic shielding gasket 30 is attached to the fixed protrusion 35, , as in the above embodiment, the movement is prevented by the stopper 31a, and the electric current is preferably Magnetic shielding can be done. Note that the present invention is not limited to the above-mentioned examples in any way, and without departing from the gist of the present invention. It goes without saying that the present invention can be implemented in various ways within a wide range of scope.

[0026] For example, when the fixing recesses 22b, 31b and the fixing protrusions 10, 35 are fitted, the conductive It may be fixed using adhesive. In addition, the through hole 21 of the cylindrical member 20 may be filled with a soft material such as sponge foam or fiber. A soft member may be arranged to adjust the elasticity.

[0027] Furthermore, the fitting parts 22 and 31 may be formed of other harder materials.

[0028]

[Effect of the idea]

As is clear from the detailed explanation above, the electromagnetic shielding member of the present invention has a cylindrical shape. Since the member has a fixing recess and a stopper, it is possible to press the electromagnetic shielding member. Even when the force is weak, the cylindrical member easily bends to ensure that the gap is sealed and It is possible to perform electromagnetic shielding.

[0029] In addition, the cylindrical member is restrained by a stopper so that it does not deflect more than a predetermined amount. It has the advantage of being less likely to be damaged. Furthermore, the electromagnetic shielding member has a fixed recess. It is easy to attach to the housing, etc. by simply fitting the part into the convex part of the housing. Ru.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of a case for explaining an embodiment of the present invention.

FIG. 2 is a sectional view of an electromagnetic shielding gasket according to an embodiment.

FIG. 3 is an explanatory diagram showing how to use the electromagnetic shielding gasket.

FIG. 4 is a sectional view of an electromagnetic shielding gasket according to another embodiment.

[Explanation of symbols]

1, 30... Gasket for electromagnetic shielding 3... Case 5... Lid body 20, 33...
Cylindrical members 22, 31...fitting portions 22a, 31
a... Stopper 22b, 31b... Fixed recess

Claims (1)

[Scope of utility model registration request] Claim 1: Used in a part where a plurality of members are in contact,
The electromagnetic wave shielding member for shielding electromagnetic waves passing between the members includes an elastic cylindrical member whose surface is conductive at least, a fixing recess inserted inside the cylindrical member, and an inner end of the fixing recess. An electromagnetic shielding member comprising: a stopper that is provided to prevent the cylindrical member from being compressed beyond a certain level.