JPH0440317Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is a waterproof and electromagnetic device that shields the leakage of high-frequency signals from electronic equipment that handles high-frequency signals housed inside, and prevents water from entering the inside. Regarding a shield device.

[Prior art]

Conventionally, waterproof and electromagnetic shielding devices as described above include cases that house, for example, head amplifiers and relay amplifiers of communal viewing devices that are often installed outdoors. An example of such a case is shown in Part 5.
As shown in the figure. In the figure, 2 is a metal box;
It is configured in the shape of a rectangular parallelepiped with one side open. Inside this box body 2, an electronic device 4 that handles high frequency signals such as a head amplifier or a relay amplifier installed in a metal amplifier case 3 is housed so as to be in contact with the inner surface of the box body 2, and a screw 6 It is fixed by. A flange 8 is formed at the periphery of the opening of the box 2. Reference numeral 10 denotes a metal lid body, which is formed in a size that can close the opening of the box body 2, and one end of which is connected to the box body 2 by a metal hinge 12 and a mounting angle 13. There is. On the inner surface of the lid body 10, a waterproof gasket 14 made of rubber and formed in a frame shape that can come into contact with the flange 8 is provided. This lid body 10 is secured by a metal fixture 16 provided on the side of the box body 2.
The opening of the box body 2 is maintained in a closed state. At this time, the box body 2 is maintained watertight by the waterproof gasket 14. In addition, metal fixtures 16 and hinges 1
2 electrically connects the box 2 and the lid 10, both of which are made of metal, and electromagnetically shields the electronic device 4 inside the box 2.

[Problem that the invention attempts to solve]

However, in the conventional waterproofing and electromagnetic shielding device as described above, the electrical connection between the box body 2 and the lid body 10 is only made by the fixture 16 and the hinge 12, so that Therefore, the contact area between the box body 2 and the lid body 10 is small, and the lid body 10 is in a floating state in terms of high frequencies. Therefore, if there is high frequency radiation from the electronic device 4 housed in the box 2,
There was a problem in that the lid 10 acted as an antenna, causing radio wave leakage.

[Means for solving problems]

In order to solve the above problems, this invention consists of a metal box body that has an opening and houses electronic equipment that handles high-frequency signals inside, and a metal box body that is attached to the opening of the box body so that it can be opened and closed. and a frame-shaped waterproof gasket provided between the box and the lid, in contact with both of them and surrounding the opening, wherein the waterproof gasket is provided on the box. A plurality of through holes are formed that penetrate from the surface that contacts the lid to the surface that contacts the lid, and when the lid is closed, a plurality of conductive rod-like members each having a proximal end on the box side are inserted into each through hole. It passes through the hole and extends toward the lid. A conductive member is provided at the tip of the rod-like member, for example, to make surface contact with the lid when the lid is closed. Further, the pressing member presses the conductive member toward the lid, for example. Of course, the proximal end of the conductive rod-like member is provided on the lid side, a conductive member is provided at the tip of this rod-like member in surface contact with the box body, and this conductive member is pressed toward the box body side by a pressing member. You can.

[Action/Effect]

According to this invention, the lid and the box are electrically connected by a plurality of conductive rod-shaped members and conductive members provided in each through hole of the waterproof packing. It is maintained at substantially the same potential as the box body in terms of high frequency. Therefore, even if there is radio frequency radiation from the electronic equipment housed within the box, the lid will not act as an antenna, and leakage of radio waves can be reduced. Furthermore, since the waterproof gasket is in close direct contact with both the lid and the box, there is no chance of water seeping into the box, similar to the conventional case.

〔Example〕

An embodiment of this invention will be described with reference to FIGS. 1 to 3. This idea is based on waterproof packing 14
The structure is similar to the conventional one shown in FIG. 5, except that a plurality of through holes are provided in the through holes and a conductor is provided in the through holes. Therefore, the same reference numerals are given to the parts equivalent to those of the conventional one, and the explanation thereof will be omitted.

A plurality of through holes 17, 17, . . . are formed in the waterproof gasket 14 from the side in contact with the lid 10 to the side in contact with the flange 8 of the box body 2. The waterproof gasket 14 is bonded to the lid 10 with, for example, an adhesive. As shown in the enlarged view of Figure 3, the box 2
The flange 8 has a conductive rod-like member, for example, a conductive pin 19, which has a conductive member, for example, a contact metal piece 18 at its tip, at a location facing the through hole 17 of the waterproof gasket 14. It is planted between the metal piece 18 and the flange 8,
A pressing member, for example a spring 20, which presses the metal piece 18 to the side opposite to the flange 8 is interposed. pin 19
passes through the through hole 17 when the opening of the box body 2 is closed with the lid 10, and the metal piece 18 at the tip of this pin 19 comes into surface contact with the lid 10. At the same time, the metal piece 18 is pressed toward the lid 10 by the spring 20. Therefore, the metal piece 18 and the pin 19 connect the lid 10 and the box 2 at high frequency. Of course, the pin 19 may be attached to the lid 10 side, and the metal piece 18 may be attached to the flange 8 side of the box body 2.

In this embodiment, the fixture 1 is shown in FIG.
When the opening of the box body 2 is closed with the lid body 10 by the lid member 6, the lid body 10 and the box body 2 are connected to each other by a plurality of pins 19 provided in the waterproof gasket 14 in addition to the fixing member 16 and the hinge 12. Since the lid body 10 is electrically connected to the box body 2 by the metal piece 18, the lid body 10 is electrically connected to the box body 2 by the metal piece 18.
becomes substantially the same potential. Therefore, even if high frequency radiation is emitted from the electronic device 4, the lid 10 does not act as an antenna, and leakage of radio waves is significantly reduced.
This state is shown in FIG. In the same figure, the symbol A
The curve shown in the figure shows the relationship between the electric field strength and frequency of leaked radio waves in the conventional waterproofing and electromagnetic shielding device, and the curve shown with the symbol B in the figure shows the relationship between the electric field strength and frequency of the leakage radio wave in the conventional waterproofing and electromagnetic shielding device. It shows the relationship between the electric field strength and frequency of leaked radio waves. As can be seen from this figure, the waterproof and electromagnetic shielding device of this invention reduces the electric field strength of leaked radio waves by about 10 dB over the entire target frequency range, reducing leakage radio waves.

In addition, in the waterproofing and electromagnetic shielding device of this invention, since the waterproofing gasket 14 is in close direct contact with both the lid 10 and the box 2, there is no fear that the waterproofing effect of the box 2 will deteriorate. .

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of an embodiment of the waterproof and electromagnetic shielding device according to this invention, Figure 2 is a back view of the lid of the same embodiment, and Figure 3 is a diagram showing the lid and box of the same embodiment. An enlarged cross-sectional view of a part of the facing surface, FIG. 4 is a diagram showing the relationship between the electric field strength and frequency of leaked radio waves of the same embodiment and the conventional waterproofing and electromagnetic shielding device, and FIG. 5 is a diagram of the conventional waterproofing and electromagnetic shielding device. FIG. 3 is a longitudinal cross-sectional view of the device. 2...Box body, 4...Electronic equipment, 10...Lid body,
14...Waterproof packing, 17...Through hole, 20
...Spring, {18...Metal piece, 19...Pin} Conductor.

Claims (1)

[Scope of utility model registration request] A metal box having an opening and accommodating electronic equipment that handles high-frequency signals inside, a metal lid attached to the opening of the box so that it can be opened and closed, and a combination of the box and the lid. A frame-shaped waterproof gasket is provided in between, which contacts both of these and surrounds the opening; A plurality of through holes are formed so as to connect the box body and the lid, and when the lid body is closed, one of the box body and the lid body is provided with a proximal end portion extending inside each of the through holes. a conductive rod-like member having a tip located on the other side of the body; and a conductive rod-like member provided at the tip of the conductive rod-like member and in surface contact with the other of the box and the lid when the lid is closed. A waterproof and electromagnetic shielding device comprising: a conductive member; and a pressing member pressing the conductive member against the other side of the box and the lid.