JP3844600B2 - Electromagnetic contact method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetic contact system.
In today's information-oriented society, with the development of various electronic devices, the use of radio waves as an information transmission means has increased dramatically. On the other hand, the malfunction of electronic devices due to incoming radio waves has been prevented. There are increasing demands for effective use of radio waves by installing PHS, prevention of wireless microphone interference, and wiretapping, and even in building spaces, there is a demand for accurate electromagnetic shielding for the entire building or for each space. It is increasing.
In particular, when electromagnetically shielding a building space, the present invention uses electromagnetic contacts for joints such as door / inspection frame and door (or lid), window frame and shoji, and two removable shield members. It is related to the system.
[0002]
[Prior art]
Conventional methods of this type include the following.
1. Contact method using beryllium copper shield finger (hereinafter referred to as beryllium finger)
(1) Explanation of method In this method, in the space subjected to electromagnetic shielding treatment, between the doorway and the door, between the inspection port and the door, and other electromagnetic shield joints, as shown in FIG. In addition, two rows of beryllium fingers a (see FIG. 16) are arranged with their contact surfaces facing each other, and a metal plate b with good electrical conductivity is vertically associated with the other B facing each other. Is inserted between the two beryllium fingers a, and one row of the beryllium finger a (see FIG. 16) is opposed to one side A shown in FIG. 17, and the other side B is opposed to the contact surface. There is a system in which a metal plate c having good electrical conductivity is horizontally corresponded to the other side B which is arranged and confronted, and this metal plate c is brought into pressure contact with the berylluminger a on the surface.
[0003]
(2) Problems However, the former case has the following problems.
(1) By repeatedly opening and closing, the fingers of the beryllium fingers are deformed or broken, and the performance is remarkably lowered, and the opening and closing is often hindered.
(2) In order to achieve electrical continuity with the metal plate inserted by the reaction force of the beryllium finger, a considerable force is required for drawing / insertion during opening and closing. It's not a configuration.
(3) By repeatedly opening and closing, the reaction force of the beryllium finger a is reduced, leading to a reduction in electromagnetic shielding performance.
(4) Maintenance frequency is high due to (1) and (2).
[0004]
The latter case also has the following problems.
(1) Since the surface contact is caused by pressurization, the performance balance is poor (or lowered) unless a mechanism that uniformly pressurizes the entire periphery of the door or frame is provided.
{Circle around (2)} Because of the surface contact, the performance is remarkably lowered when non-conducting substances (dust, oil, rust, etc.) adhere to the contact surface of the beryllium finger a or the contact surface of the metal plate c.
{Circle around (3)} Since the beryllium finger a is exposed, the finger is easily damaged during normal entry / exit or loading of an article.
Maintenance frequency is high due to (4), (2) and (3).
[0005]
2. Contact method using gasket with braided wire
(1) Explanation of method In this method, in the space subjected to electromagnetic shielding treatment, between the entrance and the door, between the inspection port and the door, and other electromagnetic shield joints, as shown in FIG. In addition, a braided wire gasket d with a metal braided wire is arranged on the other side, and conductive ribs e are arranged on the opposite side B, and the ribs e are pressed against the braided wire gasket d. There are a system and a system shown in FIG. 19 in which the above-mentioned gaskets d and d with braided wires are arranged facing each other on both sides A and B so as to contact each other.
[0006]
(2) Problems However, in these cases, there are the following problems.
(1) By repeatedly opening and closing, the metal fibers constituting the gasket d with braided wire are worn and broken, and the performance is deteriorated.
{Circle around (2)} Since the contact portion of the braided wire gasket d is exposed and has a mesh shape, non-conducting substances (dust, oil, rust, etc.) are likely to adhere to it, leading to performance degradation.
(3) In order to place each other in a normal closed state, it is necessary to operate with a considerable pressure against the reaction force of the gasket d with braided wire. It is not a functional mechanism.
{Circle around (4)} In any case, the performance is ensured by surface contact, and it is not easy to bring each part into uniform contact, and there is a limit to obtaining high performance.
Maintenance frequency is high due to (5) (1) (2).
[0007]
3. Contact method using conductive brush or conductive contact piece (Japanese Patent Publication No. 6-33699, Japanese Patent Laid-Open No. 2-2000, Japanese Patent Laid-Open No. 55-101691)
(1) Explanation of method This method uses a conductive brush on the other side of the space where electromagnetic shielding is applied, between the doorway and the door, between the opening and the cover plate, and other electromagnetic shield joints. Alternatively, a conductive contact piece is arranged and brought into contact with the other conductive plate surface facing it.
[0008]
(2) Problems (1) By repeatedly opening and closing, the conductive brush or the conductive contact piece is deformed or broken, and the performance is remarkably deteriorated and the opening and closing is often hindered.
(2) The contact portion of the conductive brush or conductive contact piece is exposed at all times or during opening and closing, and non-conducting substances (dust, oil, rust, etc.) are likely to adhere, which leads to performance degradation.
(3) In order to position each other in a normal closed state, it is necessary to operate with a considerable pressure against the reaction force of the conductive brush or conductive contact piece. Depending on the application, it is not a functional mechanism.
{Circle around (4)} This is a method of ensuring performance by surface or line contact. It is not easy to press each part uniformly, and there is a limit to obtaining high performance.
Maintenance frequency is high due to (5) (1) (2).
[0009]
These conventional methods require a heavy-tightening mechanism or the like to ensure performance, and are difficult to use and inconvenient as an architectural function.
[0010]
[Problems to be solved by the invention]
The present invention is intended to solve these conventional problems, and at the same time, facilitates operability and workability at the time of opening and closing, and is intended to be applicable to various purposes.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the first means is:
Applied between separable joints in the building,
It consists of two members that are attached to the opposing surfaces of each joint and are provided so that they can contact each other.
In an electromagnetic contact system in which a large number of contact pieces, which are short metal wires, are densely planted on the contact surface side of the first member, and these short metal wires are in electrical contact with the corresponding surfaces of the second member, respectively . ,
The first member is a metal brush 1 having a brush surface at the tip of the short metal wires by projecting a large number of thin short metal wires 3 from the conductive material 2 in a straight line .
The second member is a gasket 4 with a braided wire formed by covering the outer periphery of the elongated gasket 5 with a mesh-like thin metal braided wire 6 along the outer peripheral surface ,
The tip of each metal short wire is inserted into the mesh hole of the braided wire 6 by bringing the brush surface of the metal brush 1 and one surface of the gasket 4 with braided wire to face each other and contacting and separating the joints. Furthermore, they are meshed with each other so that they can come out of the holes .
[0017]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2 show one embodiment according to a reference example of the present invention (the invention described in the claims) . In the present specification, the reference example refers to a configuration of the invention described in the claims at the beginning of the application together with the present invention, and serves as a reference for understanding the technical significance of the present invention . In this example, two appropriate length metal brushes 1 formed by densely planting a large number of thin metal short wires 3 in the groove-shaped conductive material 2 and caulking both side walls of the groove-shaped conductive material 2 from both sides are provided. The space between the doorway 19 and the door 20 of the space subjected to electromagnetic shielding treatment is mounted so as to face each other with a brush surface, and is engaged with each other so as to be freely inserted and removed.
[0018]
3 and 4 show another reference example of the present invention . In this case, instead of caulking both side walls of the grooved conductive material 2 from both sides in the case of FIG. 1 and FIG. These short metal wires 3 are soldered to the groove-shaped conductive material 2. Others are the same as the case of FIG. 1, FIG.
[0019]
5 and 6 show an embodiment according to the present invention , and an appropriate length metal brush 1 (FIG. 4) in which a large number of thin metal short wires 3 are soldered and closely planted in a groove-shaped conductive material 2. Between the doorway 19 and the door 20 of the space subjected to electromagnetic shielding treatment, and the brushed surface 4 of the appropriate length and the outer periphery of the elongated gasket 5 covered with a thin metal braided wire 6. The brush surface of the metal brush 1 and the one surface of the gasket 4 with braided wire are mounted facing each other and engaged with each other so as to be freely inserted and removed.
[0020]
7 and 8 show still another reference example of the present invention, in which a corrugated conductive strip 7 having triangular corrugated strips 9 formed on one surface of an elongated metal strip 8 and a grooved conductive material. 2 and an appropriate length of a metal brush 1 (see FIG. 4) in which a large number of thin metal short wires 3 are densely planted, and the corrugated conduction between the doorway 19 and the door 20 of the space subjected to electromagnetic shielding treatment. The concavo-convex surface of the belt plate 7 and the brush surface of the metal brush 1 are mounted facing each other and engaged with each other so as to be freely inserted and removed.
[0021]
FIG. 9 to FIG. 11 show still another reference example of the present invention . An appropriate length metal bristle brush 10 in which a large number of metal bristle 12 is implanted on one surface of an elongated conductive strip 11, and an elongated metal wire. The metal wire bristle bar 13 with the outer periphery of the bristle bar 14 covered with the metal mesh 15 is connected to the bristle surface of the metal bristle brush 10 between the doorway 19 and the door 20 of the space subjected to electromagnetic shielding treatment. The meshed metal wire bristle bar 13 is mounted so as to face each other, and is meshed so as to be detachable from each other.
[0022]
FIG. 12 and FIG. 13 show still another reference example of the present invention . The finned conductive strip 16 having a plurality of fins 18 projecting from one surface of the elongated metal strip 17 and the groove-shaped conductive member 2. An appropriate length of the metal brush 1 (see FIG. 4) in which a large number of thin metal short wires 3 are soldered and densely planted therein is connected between the doorway 19 and the door 20 of the space subjected to electromagnetic shielding treatment. The fin surface of the finned conductive strip 16 and the brush surface of the metal brush 1 are mounted so as to face each other and engage with each other so as to be freely inserted and removed.
[0023]
FIG. 14 shows still another reference example of the present invention, in which a metal bristle brush 10 (see FIG. 10) of an appropriate length in which a large number of metal bristle 12 is implanted on one surface of an elongated conductive strip 11, and a groove. An appropriate length metal brush 1 (see FIG. 4), which is densely planted by soldering a number of thin metal short wires 3 in the shape conducting material 2, is placed between the doorway 19 and the door 20 of the space subjected to electromagnetic shielding treatment. The bristle surface of the metal bristle brush 10 and the brush surface of the metal brush 1 are mounted so as to face each other, and are detachably engaged with each other.
[0024]
In the above embodiment, the space between the doorway 19 and the door 20 of the space subjected to electromagnetic shielding treatment is targeted, but the present invention is not limited to this, and other electromagnetic shield joints between the inspection port and the door. Can also be targeted.
In addition, the material of the above-described groove-shaped conductive material 2, the short metal wire 3, the conductive belt material 5, the metal bristle 6, the braided wire 9, the metal belt plate 11, the metal mesh 15, the metal belt plate 17 and the like are stainless steel, brass, copper It is a material with high electrical conductivity such as iron, and the length, diameter, hardness, density or arrangement method can be considered in several ways.
[0025]
(1) Theoretical structure The method of joining members to enhance the electromagnetic shielding effect is that the electric resistance value is small and uniform (rectified) when incoming radio waves flow as a weak high-frequency current on a shield surface composed of a metal body. What is necessary is just to comprise the shape to pass. Also, at this time, the gap should be reduced as much as possible. In order to form such a shape with the member joint portion (contact portion), it is only necessary to construct more joint surfaces.
At that time, since the conventional system (FIGS. 15 to 19) has a surface contact structure, if there is a contact failure part in part, the passing current does not flow in a uniform (rectified) state and is re-radiated as a radio wave. At the same time, if a part of the contact portion exists as a gap, the incoming radio wave passes through and enters.
However, in this method, by inserting a plurality of short metal wires arranged densely in the vertical direction, the state in which the short metal wires contact with each other (electric conduction) can be configured with high density and uniform (rectification) ) Current flows. In addition, in the contact state of a plurality of short metal wires arranged densely, there is an insertion length, so that generation of a large (long) gap is extremely small compared to the surface contact method.
From the above, stable electromagnetic shielding characteristics can be obtained.
[0026]
(2) Electromagnetic shielding performance The electromagnetic shielding performance of this contact system depends on the insertion length, diameter, hardness, density, or arrangement method of short metal wires, etc., but considerable performance can be expected from the configuration theory.
Here, the effect prediction is calculated by the case of the metal brushes 1 in FIG.
Assume that the state where the joint is completely continuously joined is 100%, and in this method, there is a gap and it is in electrical contact with the former by about 25% (individual states are completely electrically conductive). Suppose you are).
When the contact width is very small, the unit length is 10 mm, the short metal wire diameter is 0.3 mm, and the contact points are evenly spaced, the gap is 100 mm ÷ 0.30 mm × 25% = 83.33 in contact. Yes, 100 mm ÷ 83.33 = 1.2 mm is the contact interval.
Further, when the metal short wire diameter 0.3 mm × (1-2) is subtracted, the gap becomes about 0.9-0.6 mm.
Slit theoretical formula S = -20 log (λ / 2L)
S: Shield performance (dB)
λ: Wavelength (m)
L: Clearance length (m)
Thus, when the shielding performance at a wavelength of 0.3 m (1000 MHz) is confirmed, it becomes 57.4 dB or less.
Such a numerical value can be obtained from the theoretical formula, but as a part that cannot be clarified, how much electric resistance the contact state of the short metal wire can be accommodated, or how the performance changes by increasing the width of the brush It is unknown.
In addition, since the metal short wire of the metal brush is not completely elastic, an increase in contact resistance due to secular change can be considered, but this can be solved by slightly shifting one of the meshing members (metal bristle brush or angle member) In this case, 1/2 of the pitch). For this, a method of shifting the fixing screw hole as a fool hole every predetermined period or a method of reciprocating using a pressing force can be considered.
[0027]
(3) Ease of use (ease of opening and closing)
Depending on the required electromagnetic shielding performance, a large contact pressure is required for the contact mechanism (to obtain electrical continuity) if the performance is about 40 to 50 dB required for general electromagnetic shielding and event halls. Therefore, for example, a door can be opened and closed with a light operation mechanism (about a lever handle) as compared with a conventional shield door (gremon handle or the like).
[0028]
(4) Maintainability Since the metal short wires 1 contact each other every time the metal short wires are opened and closed, the metal short wires are constantly polished and electrical conduction is ensured. From this, it can be said that the maintenance frequency is remarkably low as compared with the conventional surface contact method (conventional method of FIGS. 15 to 19).
[0029]
【The invention's effect】
According to the present invention, since it is the above-described configuration, the contact area between each other can be expanded by the removably inserted, and the mutual contact (electrical conduction) state can be configured with high density, The energization state of each part can be made almost uniform (rectification), and therefore, the contact can be generally secured, the generation of gaps can be minimized, and stable electromagnetic shielding characteristics can be obtained.
In addition, a large surface pressure is not required, and therefore, the door and the like can be lightly opened and closed, making it easy to use.
Further, since they are brought into contact with each other, they are polished each time they are brought into contact with each other, so that electrical continuity can be ensured. Therefore, the maintenance frequency is remarkably reduced and the maintainability can be improved as compared with the conventional surface contact method.
[0030]
The buildings that currently require electromagnetic shielding are classified according to function and application from the applicant's construction project. (1) Broadcast studio, (2) Event hall, (3) Government office, (4) Radio measurement facility And so on. In view of the recent need for electromagnetic shielding, (5) CPU rooms of financial institutions, (6) hotel lobbies, and (7) intelligent offices are also targeted. Thus, except for special facilities such as radio wave measurement facilities, most are buildings and spaces that require a general idea. For example, in the case of a door, considering the functionality and safety (evacuation) as an architecture, the doorway to be installed must have a light operating mechanism and have sufficient electromagnetic shielding performance. From this aspect, the range of utilization of this method is considered to be wide and effective.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a reference example of the present invention .
FIG. 2 is a cutaway perspective view of a main part member of the example .
FIG. 3 is a cross-sectional view showing another reference example of the present invention .
FIG. 4 is a cutaway perspective view of a main part member of the same example .
FIG. 5 is a cross-sectional view showing an embodiment according to the present invention .
FIG. 6 is a cutaway perspective view of a main part member in the same embodiment;
FIG. 7 is a cross-sectional view showing another reference example of the present invention .
FIG. 8 is a cut perspective view of a main part member of the example .
FIG. 9 is a cross-sectional view showing another reference example of the present invention .
FIG. 10 is a cutaway perspective view of one main part member of the example .
FIG. 11 is a cut perspective view of another main part member of the example .
FIG. 12 is a cross-sectional view showing another reference example of the present invention .
FIG. 13 is a cut perspective view of a main part member of the example .
FIG. 14 is a cross-sectional view showing another reference example of the present invention .
FIG. 15 is a cross-sectional view showing a first conventional example.
FIG. 16 is a perspective view of a main part member of the same example.
FIG. 17 is a cross-sectional view showing a second conventional example.
FIG. 18 is a cross-sectional view showing a third conventional example.
FIG. 19 is a cross-sectional view showing a fourth conventional example.
[Explanation of symbols]
A ... One B ... The other a ... Beryllium finger b, c ... Metal plate d ... Braided wire gasket e ... Projection 1 ... Metal brush 2 ... Groove-shaped conductive material 3 ... Metal short wire 4 ... Braided wire gasket 5 ... Gasket 6 ... Braided wire 7 ... Corrugated conductive strip 8 ... Metal strip 9 ... Uneven strip 10 ... Metal bristle brush
11 ... Conductive strip 12 ... Metal bristle
13… Metal wire bristle with mesh 14… Metal wire bristle
15 ... Metal mesh 16 ... Conductive strip with fin
17 ... Metal strip 18 ... Fin
19 ... Entrance 20 ... Door

Claims (1)

Applied between separable joints in the building,
It consists of two members that are attached to the opposing surfaces of each joint and are provided so that they can contact each other.
In an electromagnetic contact system in which a large number of contact pieces, which are short metal wires, are densely planted on the contact surface side of the first member, and these short metal wires are in electrical contact with the corresponding surfaces of the second member, respectively . ,
The first member is a metal brush 1 having a brush surface at the tip of the short metal wires by projecting a large number of thin short metal wires 3 from the conductive material 2 in a straight line .
The second member is a gasket 4 with a braided wire formed by covering the outer periphery of the elongated gasket 5 with a mesh-like thin metal braided wire 6 along the outer peripheral surface ,
The tip of each metal short wire is inserted into the mesh hole of the braided wire 6 by bringing the brush surface of the metal brush 1 and one surface of the gasket 4 with braided wire to face each other and contacting and separating the joints. Further , the electromagnetic contact system characterized in that they are meshed with each other so that they can come out of the hole .

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