JP2009043773A - Hermetically-sealing structure for electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hermetically-sealing structure which is easily handled and can maintain excellent sealing performance between two members of a lid member and a housing by preventing a possibility of the bite-in an O-ring between the two members. <P>SOLUTION: The hermetically-sealing structure is provided with: an O-ring formed of a rubber elastic material disposed in a circular groove formed on the external circumferential surface of the lid member of an electronic device; and a housing for receiving the lid member and having a circular internal circumferential surface hermetically contacting the O-ring, wherein the external circumferential surface is a rectangular shape and the lid member conducts opening/closing movement with a short side surface as a fulcrum. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a sealing structure for an electronic device.
The present invention also relates to a sealing structure for an electronic device having a waterproof function.

Furthermore, the present invention relates to a sealing structure for an electronic device that prevents external water or the like from entering the electronic device from a lid member that opens and closes.
Furthermore, the present invention is effectively used as a sealing structure for electronic devices such as digital cameras.

2. Description of the Related Art Conventionally, a lid member of an electronic device, for example, a lid member used for a connection terminal portion or a battery housing portion of a digital camera or the like is provided with a sealing member for the purpose of waterproofing.
In general, for such a sealing member, a low-hardness silicone rubber excellent in adhesion to the housing side and followability is used.
The O-ring used for the sealing structure for an electronic device is attached to the lid member by placing the O-ring in an annular groove provided on the outer peripheral surface of the lid member.

However, waterproof gaskets made of low-hardness silicone rubber tend to stretch and twist easily, especially when placed in a groove provided on a rectangular outer peripheral surface, the groove cannot follow the groove at an intermediate position in the longitudinal direction. Sagging occurred.
Specifically, as shown in FIGS. 4 and 5, a state in which the O-ring 20 is lifted from the groove 120 provided on the outer peripheral surface 110 of the lid member 10 is invited.
5 is a cross-sectional view taken along the line CC of FIG.

As a result, in this state, when the lid member 10 of FIG. 4 is closed toward the housing 30, the problem that the O-ring 20 is caught between the lid member 10 and the housing 30 is caused.
This tendency was remarkable in the vicinity of the central portion of the O-ring 20 in the longitudinal direction of the lid member 10.
This is because, when the O-ring 20 is disposed in a groove provided on the rectangular outer peripheral surface, there is a strong tendency for slack that cannot follow the groove at an intermediate position in the longitudinal direction.

JP-A-7-297895

  The present invention has been made in view of such problems, is easy to handle, has no fear of biting the O-ring between the lid member and the housing, and maintains good sealing performance between the two members. An object is to provide a sealing structure for an electronic device.

  The sealing structure for an electronic device according to the present invention includes an O-ring made of rubber-like elastic material disposed in an annular groove provided on an outer peripheral surface of a lid member of the electronic device, and the lid member, and seals the O-ring. In the sealing structure including a housing having an annular inner peripheral surface in contact with the housing, the outer peripheral surface is rectangular, and the lid member is opened and closed with a short side surface as a fulcrum.

The present invention has the following effects.
According to the sealing structure for an electronic device according to the first aspect, there is no fear that the O-ring is caught between the lid member and the housing, and a good sealing performance between the two members can be maintained.
Further, according to the sealing structure for an electronic device according to the second aspect, the sliding between the housing and the O-ring can be smoothly performed in the initial stage of closing the lid member.

Further, according to the sealing structure for an electronic device according to the third aspect, the manufacturing can be performed at a low cost, and a good sealing performance can be exhibited.
According to the sealing device of the fourth aspect, the sliding resistance when the lid member is opened and closed can be lowered, and the twisting of the O-ring can be prevented.

Further, according to the sealing structure for an electronic device according to the fifth aspect, the sliding resistance when the lid member is opened and closed can be lowered, and the O-ring can be more reliably prevented.
Similarly, according to the sealing structure for an electronic device according to the sixth aspect, the sliding resistance when the lid member is opened and closed can be lowered, and the O-ring can be more reliably prevented from being bitten.

Hereinafter, the best mode for carrying out the present invention will be described.
The best mode for carrying out the invention will be described with reference to FIGS.
2 is a cross-sectional view taken along the line AA in FIG.
3 is a cross-sectional view taken along the line BB of FIG.

The sealing structure for an electronic device receives an O-ring 2 made of rubber-like elastic material disposed in an annular groove 12 provided on the outer peripheral surface 11 of the lid member 1 of the electronic device, and receives the lid member 1, and receives the O-ring 2. And a housing 3 having an annular inner peripheral surface 31 in sealing contact.
The annular groove portion 12 is provided on the outer peripheral surface of the rectangular convex portion 13 provided on the side surface on the closing side of the lid member 1, but is not provided with the convex portion 13 and directly on the outer peripheral surface of the lid member 1. It may be provided.

The outer peripheral surface 11 has a rectangular shape, and the lid member 1 is configured to open and close using the short side surface 14 as a fulcrum 15.
The rectangular shape means a rectangular shape, but the corner portion may be an arc shape or a shape in which each side is entirely curved.
For this reason, in this embodiment, the outer peripheral surface 11 on the short side surface 14 side is an arc-shaped portion 111.

Further, the fulcrum 15 of the opening / closing movement of the lid member 1 is made of a resin material integrally with the lid member 1. For this reason, not only can it be manufactured at low cost, but also the structure is simple, so that it is easy to obtain a good sealing structure.
Further, since the surface of the O-ring 2 is treated with a surface treatment agent or treated with a satin finish, the sliding resistance when the lid member is opened and closed can be lowered, and twisting of the O-ring can be prevented.
Moreover, since the familiarity is improved, the risk of sagging can be effectively avoided.

  The O-ring 2 has a hardness in the range of JISA 50 to 70 °, and is made of synthetic rubber such as silicone rubber, fluorine rubber, NBR, hydrogenated NBR, EPDM, SBR, acrylic rubber, natural rubber, thermoplastic elastomer, etc. Are appropriately selected and used.

Furthermore, as the surface treatment agent for the O-ring 2, a reactive surface treatment agent, a silicone coating agent, a fluorine coating agent, or the like is appropriately selected and used, and a reactive surface treatment agent is particularly preferable.
By treating the surface of the O-ring 2, when the O-ring 2 is mounted in the groove portion 12, the familiarity of the O-ring 2 is improved, so that the risk of sagging can be effectively avoided.
As this reactive surface treating agent, a silyl isocyanate compound having a Si-NCO group is employed.

As this kind of compound, one NCO group was bonded to a silicon atom, triethylsilyl isocyanate [(C2H5) 3SiNCO], three NCO groups were bonded to a silicon atom,
Butoxysilane triisocyanate [C4H9OSi (NCO) 3] or the like can be used alone or in combination.

(ここで、Rはアルキル基、アリール基またはイソシアネート基であり、nは1以上の整数である)で表わされるシリルイソシアネートオリゴマーおよび(4)有機溶媒可溶性ゴムよりなる反応性表面処理剤。 In particular, a reactive surface treatment agent comprising the following combinations is preferably used.
(1) a reaction product of a polysiloxane containing a terminal hydroxyl group and a silyl isocyanate,
(2) a reaction product of an oligomer containing a functional group having reactivity with an isocyanate group and silyl isocyanate,
(3) General formula

(Wherein R is an alkyl group, an aryl group or an isocyanate group, and n is an integer of 1 or more) and (4) a reactive surface treating agent comprising an organic solvent-soluble rubber.

  The polysiloxane containing a terminal hydroxyl group that forms the reaction product of component (1) is a polysiloxane having at least one terminal hydroxyl group in the molecule, such as α, ω-dihydroxypolydimethylsiloxane, α, ω- Dihydroxypolydiphenylsiloxane or the like is used, and those polysiloxanes having a viscosity (room temperature) of about 100 to 100,000 cst, preferably about 100 to 10,000 cst are used.

  The oligomer that forms the reaction product of component (2) includes a functional group having reactivity with an isocyanate group such as a hydroxyl group, a carboxyl group, an amino group, and a thiol, and a molecular weight of about 10,000 or less, preferably about 1000. ~ 7000 oligomers are used, for example, oligomeric polyester resins having these functional groups, butyral resins, acrylic resins, fluororesins, nitrocellulose, etc., preferably hydroxyl group-containing polyester resins, hydroxyl group-containing fluororesins, Butyral resin, nitrocellulose and the like are used.

  The polysiloxane and oligomer having these functional groups are used after reacting with silyl isocyanate in an equivalent amount or more, generally 1 to 100 times equivalent, preferably 1 to 50 equivalents in advance. Examples of the silyl isocyanate include methyl triisocyanate silane, ethyl triisocyanate silane, isopropyl triisocyanate silane, butyl triisocyanate silane, phenyl triisocyanate silane, dimethyl diisocyanate silane, diethyl diisocyanate silane, and tetraisocyanate silane.

  The reaction between the polysiloxane or oligomer having a reactive functional group and the silyl isocyanate is carried out by dropping silyl isocyanate into an organic solvent solution of the polysiloxane or oligomer, and the polysiloxane and the oligomer are generally separated from each other. Although it is made to react, it is also possible to react simultaneously. The reaction is carried out at room temperature to about 150 ° C, preferably room temperature to about 100 ° C.

  As the organic solvent used as the reaction solvent, any solvent can be used as long as it dissolves polysiloxane or oligomer and does not react with isocyanate groups. For example, ethyl acetate, butyl acetate, propylene glycol monomethyl acetate, ethyl cellosolve Esters such as acetate, ethers such as dibutyl ether, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether and tetrahydrofuran, aromatic hydrocarbons such as toluene and xylene, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, dimethyl Protic polar solvents such as formamide, dimethylacetamide, dimethylsulfoxide, N-methyl-2-pyrrolidone, etc. are used alone or in combination

  As the silyl isocyanate oligomer of component (3), those represented by the above general formula are used, wherein R is an aryl group represented by an alkyl group such as a methyl group, an ethyl group, an isopropyl group, or a butyl group, or a phenyl group. Or it is an isocyanate group, and n is preferably 1-4.

  Further, the organic solvent-soluble rubber of component (4) includes NBR, SBR, isoprene rubber, butadiene rubber, chloroprene rubber, butyl rubber, EPDM, urethane rubber, fluoro rubber, acrylic rubber, epi rubber, which are soluble in various organic solvents as described above. Synthetic rubber or natural rubber such as chlorohydrin rubber, chlorinated polyethylene, chlorosulfonated polyethylene, etc., preferably NBR, particularly preferably carboxyl group or hydroxyl group-containing NBR, carboxyl group or amino group modified butadiene-acrylonitrile copolymer, etc. Is used.

  In each of the above components, the component (1) is about 1 to 50% by weight, preferably about 1 to 10% by weight, the component (2) is about 1 to 50% by weight, preferably about 1 to 10% by weight, (3 ) Component is used in an amount of about 3 to 50% by weight, preferably about 3 to 20% by weight, and (4) component is used in a proportion of about 0.01 to 10% by weight, preferably about 0.05 to 5% by weight, with the remainder being organic It consists of a solvent.

  In the mixing ratio of each of these components, the non-adhesiveness decreases with the (1) component, and the adhesiveness decreases with the (2) component, (3) component, and (4) component. Will come to do. On the other hand, if it is used in a proportion higher than this, the component (1) will come off, the (2) component, the (4) component will be non-tacky, and the (3) component will be a pot. Life is shortened.

  The surface treatment agent containing the above components as essential components is once prepared as an organic solvent solution having a solid content concentration of about 5 to 20% by weight, and further diluted with an organic solvent according to the coating thickness and coating method. To be used.

  The coating thickness is usually about 1 to 20 μm, preferably about 2 to 10 μm. If the coating thickness is less than this, not all of the treatment surface can be covered, and not only the non-adhesiveness is impaired, but also applied to the sealing material. If this happens, the sealing performance will be impaired. On the other hand, if the coating thickness is thicker than this, the rigidity of the sealing material surface becomes high, and the sealing performance and flexibility may be impaired. The application method is also arbitrary, and generally a dipping method, a spray method, a roll coater method, a flow coater method or the like is used. After the application, heat treatment at about 80 to 250 ° C., preferably about 120 to 200 ° C. is performed for about 3 It takes about 1 to 1 hour.

  In addition, the surface of the O-ring 2 is formed by subjecting the molding surface of the O-ring 2 to a matte finish by shot blasting or the like, or by directly applying a matte finish to the surface of the O-ring 2 after molding. Is done.

The present invention having the above-described configuration invites the following operations and effects.
That is, as shown in FIG. 2, the O-ring 2 mounted in the rectangular groove 12 does not lift up at both ends in the longitudinal direction, but as shown in FIG. 3, in the vicinity of the central portion in the longitudinal direction. Inevitably lifts up.
However, since the short side surface 14 side of the lid member 1 is used as the fulcrum 15, first, the short side surface 14 side on which the O-ring 2 does not float quickly fits within the annular inner peripheral surface 31 of the housing 3.

Subsequently, the O-ring 2 is sequentially accommodated in the annular inner peripheral surface 31 from the longitudinal fulcrum 14 side toward the center portion.
For this reason, even if the floating has occurred near the central portion in the longitudinal direction, the O-ring 2 is guided by the annular inner peripheral surface 31 and fits in the groove 12 and is not bitten.
In particular, when the surface of the O-ring 2 is surface-treated, it is possible to prevent biting more effectively.

  Further, the present invention is not limited to the best mode for carrying out the invention described above, and various other configurations can be adopted without departing from the gist of the present invention.

It is a perspective view which shows embodiment of the invention concerning the sealing structure for electronic devices. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is a perspective view which shows the sealing structure for electronic devices which concerns on a prior art. It is CC sectional drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cover member 2 O-ring 3 Housing 11 Outer peripheral surface 12 Groove part 13 Convex part 14 Short side surface 15 A fulcrum

Claims (6)

  Receiving the O-ring (2) made of rubber-like elastic material disposed in the annular groove (12) provided on the outer peripheral surface (11) of the lid member (1) of the electronic device, and the lid member (1); In a sealing structure comprising a housing (3) having an annular inner peripheral surface (31) in sealing contact with the O-ring (2), the outer peripheral surface (11) is rectangular and the lid member (1) is An electronic device sealing structure characterized by opening and closing movement with the short side surface (14) side as a fulcrum (15).   The sealing structure for an electronic device according to claim 1, wherein the outer peripheral surface (11) on the side of the short side surface (14) is an arc-shaped portion (111).   The sealing structure for an electronic device according to claim 1 or 2, wherein the fulcrum (15) is made of a resin material integrally with the lid member (1).   The sealing structure for an electronic device according to any one of claims 1 to 3, wherein a surface of the O-ring (2) is coated.   The sealing device according to claim 4, wherein the coating is treated with a reactive surface treatment agent.   The sealing structure for an electronic device according to any one of claims 1 to 3, wherein a surface of the O-ring (2) is treated with a satin finish.

Images