HK1066685B - Housing having electromagnetic wave shielding and waterproof structure - Google Patents

Description

Housing having electromagnetic wave shielding and waterproof structure

Technical Field

The present invention relates to a housing having an electromagnetic wave shielding function and a waterproof function.

Background

The present application claims priority from the prior application JP 2002-322982, the disclosure of which is incorporated by reference in the present application.

Communication devices or electronic devices require measures against electromagnetic waves, and in particular, they also require water-proof measures when placed outdoors. Therefore, housings of these apparatuses are expected to have an electromagnetic wave shielding function and a waterproof function.

Such ｃA housing is disclosed, for example, in JP- ｃA-2001-160697 and comprises ｃA case having an opening at one side thereof and having ｃA cover closing the opening. The cover is made of a magnetic metal and has a groove opposed to the edge portion of the case.

In order to perform sealing between the case and the cover, a gasket is disposed in a groove formed at an edge portion of the case. The gasket has a structure in which a conductive electromagnetic wave-shielding rubber is placed on the surface of a highly elastic rubber having excellent compression recovery properties.

After the gasket is placed in the groove of the rim portion of the case, an electronic circuit part is put into the case. Then, the cover is placed over the case, and the case and the cover are fixed together by the fixing means while the cover is pressed against the gasket. Therefore, electromagnetic wave shielding and waterproofing can be ensured between the case and the cover.

However, since the aforementioned case is constructed such that the cover is pressed against the separately formed gasket received in the groove of the edge portion of the case, a gap is easily generated between the case and the cover. Specifically, since the gasket surface formed of the electromagnetic wave shielding rubber has a relatively poor compression recovery property, the contact between the cover and the case tends to be a line contact, and further, the deviation of the members constituting the housing, which is generated at the time of manufacturing them, cannot be absorbed, so that there is a high possibility that the aforementioned gap is generated. When the gap is generated, there are problems in that electromagnetic waves permeate into the case, electromagnetic waves leak to the outside of the case, and water permeates into the case. Therefore, sufficient electromagnetic shielding and waterproof functions cannot be obtained.

Disclosure of Invention

It is therefore an object of the present invention to provide a housing having sufficient electromagnetic wave shielding and waterproofing functions even when there is a deviation in material or processing accuracy.

Other objects of the invention will become apparent as the description proceeds.

According to an aspect of the present invention, there is provided a case including a first case member made of magnetic metal and having a first surface, a second case member made of magnetic metal and having a second surface opposite to the first surface, the second case member and the first case member being fitted to define a space, and a sealing structure providing an electromagnetic wave shielding function and a waterproof function between the first case member and the second case member. The sealing structure includes a groove portion formed on a first surface and extending around the space, a first sealing member formed by being directly applied into the groove portion, the first sealing member being compressible, a second sealing member formed by being applied to the first sealing member, the second sealing member having relatively higher hardness and relatively higher flexibility and conductivity than the first sealing member, and a pressing portion protrudingly formed on a second surface to correspond to the groove portion, the pressing portion compressively deforming the second sealing member to make a surface contact with the second sealing member.

Drawings

Fig. 1 is a perspective view showing a housing in a disassembled state according to a first embodiment of the present invention;

FIG. 2 is a sectional view taken along line II-II in FIG. 1;

fig. 3 is an enlarged sectional view showing only a main portion of fig. 2;

FIG. 4 is a cross-sectional view similar to FIG. 3 with the housing in an assembled condition;

FIG. 5 is a view for describing a method of directly forming a sealing member to a housing; and

fig. 6 is an enlarged sectional view showing only a main portion of a housing according to a second embodiment of the present invention.

Detailed Description

Referring to fig. 1 and 2, a description will be given of the overall structure of the housing according to the first embodiment of the present invention.

The illustrated housing is for a communication device or an electronic device, and includes a rectangular parallelepiped case 1 made of a magnetic metal and a cover 2 made of a magnetic metal, wherein the rectangular parallelepiped case 1 functions as a first housing member and the cover 2 functions as a second housing member. The cabinet 1 has an opening 3 at its upper side. The cover 2 is used to close the opening 3 of the case 1. When the opening 3 of the case 1 is closed by the cover 2, a housing having an inner space is formed.

At four corners of the edge portion 4 defining the opening 3 of the cabinet 1 therein, protruding pieces 5 are formed, each of the protruding pieces 5 protruding outward. Similarly, the cover 2 is also formed with a plurality of protruding pieces 6, and the protruding pieces 6 are respectively opposed to the protruding pieces 5 of the case 1. In a state where the electronic circuit part 7 of the communication device or the electronic device is accommodated in the case 1 and the opening 3 is closed by the cover 2, four screws 8 (only one is shown for the sake of simplicity) are screwed as fixing members to clamp the protruding piece 5 of the case 1 and the protruding piece 6 of the cover 2 in directions approaching each other so as to fixedly join them together. In order to achieve the electromagnetic wave shielding function and the waterproof function, a sealing structure is provided between the case 1 and the cover 2.

Referring also to fig. 3 and 4, the sealing structure will be described.

On a surface (first surface) 11 of the case 1 opposed to the cover 2, a groove portion 12 is formed so as to extend in a quadrangular ring shape along the edge portion 4. A first seal 13 is provided in the groove portion 12, and the first seal 13 is made of soft silicon (soft silicon) which is a compressible soft material having low hardness. The first seal 13 is formed at a height equal to the level of the first surface 11 or does not protrude from the level of the first surface 11. The first seal member 13 is formed by being directly applied or coated into the groove portion 12 and then dried. Since being directly applied into the groove portion 12, the first seal 13 is tightly adhered to the bottom surface 12a and both side surfaces 12b of the groove portion 12, which is preferable.

Further, a second seal member 14 is provided on the first seal member 13 to close the opening of the groove portion 12. The second seal 14 has a relatively high stiffness, flexibility and electrical conductivity. More specifically, the second sealing member 14 is made of hard silicon (hard silicon) containing a metal filler as a hard material, and is formed by being directly applied or coated onto the surface of the first sealing member 13 to protrude from the first surface 11 and then dried. The second sealing member 14 is tightly adhered to the surface of the first sealing member 13 because it is directly applied to the first sealing member 13.

On a surface (second surface) 15 of the cover 2 opposed to the case 1, a pressing portion 16 is formed corresponding to the groove portion 12 to extend in a quadrangular ring shape. The pressure applying portion 16 is in the form of a protrusion from the second surface 15. Preferably, the first surface 11 and the second surface 15 are formed to extend along planes, respectively, to thereby match each other.

Referring to fig. 5, a method of directly forming the first and second sealing members 13 and 14 will be described.

In order to form the first seal 13 and the second seal 14, an automatic application unit 17 is used, which automatic application unit 17 has an outlet nozzle 18 for discharging the pasty silicon 19. Outlet nozzle 18 is located at a position facing groove portion 12.

At the time of forming the first seal member 13, the automatic application unit 17 excessively discharges the paste silicon 19 to the groove portion 12 through the outlet nozzle 18 while moving the automatic application unit 17 along the groove portion 12. This causes the paste silicon 19 to be embedded or coated into the trench portion 12 as shown in fig. 5. After being set or applied in the groove portion 12, the paste silicon 19 is dried to produce the first seal member 13. In this case, it is natural that a paste of soft silicon is used as the paste silicon 19.

At the time of forming the second seal member 14, the automatic application unit 17 excessively discharges the paste-like silicon 19 on the first seal member 13 through the outlet nozzle 18 while moving the automatic application unit 17 along the groove portion 12. This causes the paste-like silicon 19 to be placed or painted onto the first sealing member 13. After being placed or applied onto the first seal, the pasty silicon 19 is dried to produce the second seal 14. In this case, it is natural that a paste of hard silicon is used as the paste silicon 19.

Now, the operation of the aforementioned housing will be explained.

The electronic circuit part 7 of the communication apparatus or the electronic apparatus is put into the case 1, and then the cover 2 is put on the case 1. In which case the pressure applying portion 16 is located above the surface of the second seal member 14. In this state, the cover 2 is clamped to the case 1 using the screws 8. After the screw 8 is tightened, the pressing portion 16 then pushes the second seal member 14 toward the inside of the groove portion 12. Then, as shown in fig. 4, the first seal member 13 is pressed down by the pressing portion 16. Finally, the second seal member 14 is elastically deformed into a state in which the second seal member 14 does not protrude from the first surface 11 but compresses the first seal member 13, that is, a state in which the second seal member 14 is trapped in the groove portion 12. Therefore, the second sealing member 14 is brought into surface contact with the pressing portion 16 to cover it. Further, the second seal member 14 is pressed toward the pressing portion 16 by the restoring force of the first seal member 13. Therefore, the surface of the second sealing member 14 matches the surface of the pressing portion 16 to be tightly adhered thereto.

When the cover 2 is securely clamped to the case 1 using the screws 8, the second seal member 14 is pressed against the pressing portion 16 in surface contact. It can be assumed that a slight gap still exists between the first and second seals 13, 14 and the side surface 12b of the groove portion 12 due to deformation of the case 1 and/or the cover 2, or due to the absence of application of silicon, or the like. However, these gaps are reduced or eliminated because a portion of the first seal member 13 corresponding to the volume that is depressed is pushed up while contacting the side surface of the groove portion 12. Therefore, an excellent waterproof function can be ensured between the case 1 and the cover 2.

Further, since the second sealing member 14 is pressed toward the pressing portion 16 of the cover 2, particularly, toward the side surface 12b of the groove portion 12 of the case 1, the case 1 and the cover 2 are reliably and electrically connected to each other through the conductive second sealing member 14. Therefore, an excellent electromagnetic wave shielding function can be secured between the case 1 and the cover 2.

Referring to fig. 6, a case according to a second embodiment of the present invention will be explained. Like parts or portions are indicated by like reference numerals.

In the housing of fig. 6, the cover 2 is provided with a first seal 13 and a second seal 14, and the container 1 is provided with a pressure applying portion 16, said pressure applying portion 16 may be in the form of a protrusion protruding from the first surface. In this case, the cover 2 serves as a first housing member, and the case 1 serves as a second housing member.

While the invention has been thus far described in connection with a few embodiments thereof, it will be fully possible for those skilled in the art to practice the invention in various ways. For example, the first sealing member may be made of a high-molecular soft material such as a resin having moisture resistance. Further, although the housings are applicable to communication devices such as wireless base stations for portable telephones and the like, it can be readily understood that they can be applied to various other electronic devices.

Claims (12)

1. A housing, comprising:

a first housing part made of a magnetic metal and having a first surface;

a second housing part made of a magnetic metal and having a second surface opposite to the first surface, the second housing part cooperating with the first housing part to define a space; and

a sealing structure providing an electromagnetic wave shielding function and a waterproof function between the first case member and the second case member,

the seal structure includes:

a groove portion formed on the first surface and extending around the space;

a first seal formed by direct application into said channel portion, said first seal being compressible;

a second seal member formed by being applied over the first seal member, the second seal member having a relatively higher hardness than the first seal member and having a relatively higher flexibility and conductivity; and

and a pressing portion protrudingly formed on the second surface to correspond to the groove portion, the pressing portion compressively deforming the second sealing member to be brought into surface contact with the second sealing member.

2. The housing of claim 1, further comprising a joining member for clamping said first housing member and said second housing member in a direction approaching each other to join them together.

3. The housing of claim 2, wherein said engagement member comprises a screw that mates with said first and second housing members.

4. The housing of claim 1, wherein said first seal is formed so as not to protrude from said first surface and said second seal is formed so as to protrude from said first surface.

5. The housing of claim 1, wherein said first seal comprises soft silicon.

6. The case of claim 1, wherein the first sealing member comprises a soft material of a polymer having moisture resistance.

7. The housing of claim 1, wherein said second seal comprises hard silicon and a metal filler added to said hard silicon.

8. The housing of claim 1, wherein said pressing portion comprises a protrusion portion protruding from said second surface and inserted into said groove portion to contact said second sealing member.

9. The housing of claim 8, wherein said second seal member is pressed toward said projection by a restoring force of said first seal member.

10. The housing of claim 1, wherein said first housing member is a case having an opening at one side thereof and forming said space, and said second housing member is a cover closing said opening.

11. The housing of claim 1, wherein said second housing member is a case having an opening at one side thereof and forming said space, and said first housing member is a cover closing said opening.

12. The housing of claim 1, wherein said second seal member has a surface that mates with a surface of said pressure applying portion when deformed by said pressure applying portion.