JP2009041586A - Sealing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing device which can be easily handled, eliminate a risk that an O-ring bites in between a cover member and a housing, and keep favorable sealing performance between two members. <P>SOLUTION: The sealing device comprises the O-ring formed of a rubber elastic material disposed in an annular groove formed on the outer peripheral surface of the cover member of an electronic device, and a housing receiving the cover member and having an annular inner peripheral surface which seals the O-ring and contacts therewith. In the sealing device, the outer peripheral surface is rectangular, and the O-ring is installed in the groove while an inner diameter extension rate is set to be in a range of 10 to 30%. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a sealing device.
The present invention also relates to a sealing device that is useful for use in a place where two members are sealed.

Furthermore, the present invention relates to a sealing device that prevents leakage from a lid member that opens and closes.
Furthermore, the present invention is effectively used as a sealing device for electronic equipment such as a digital camera.

In particular, the present invention relates to a sealing device that seals a gap between resin casings.
Preferably, the present invention is effectively used for a lid member of a resin material casing of a digital camera.

Conventionally, a lid member of an electronic device, for example, a lid member used for a connection terminal portion of a digital camera or a battery storage portion is provided with a sealing device for the purpose of waterproofing.
In general, such a sealing device uses a low-hardness silicone rubber having excellent adhesion to the housing side and following performance.
The O-ring used in the sealing 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 the outer peripheral surface of a rectangle, following the groove at an intermediate position in the longitudinal direction. Unsatisfactory sagging occurred.
Specifically, as shown in FIG. 3, a state in which the O-ring 2 is lifted from the groove portion 12 provided on the outer peripheral surface 11 of the lid member 1 is invited.

As a result, in such a state, when the lid member 1 of FIG. 1 is closed toward the housing 3, there is a problem that the O-ring 2 is caught between the lid member 1 and the housing 3.
This tendency was prominent when the O-ring linearity was very thin, 0.4 mm to 1.6 mm.

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. It aims at providing the sealing device which can be performed.

  The sealing 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 an electronic device, and an annular shape that receives the lid member and seals and contacts the O-ring. In a sealing device including a housing having an inner peripheral surface, the outer peripheral surface is rectangular, and the O-ring is mounted in the groove portion with an inner diameter extension rate set in a range of 10 to 30%. Features.

The present invention has the following effects.
According to the sealing device of the first aspect, there is no fear of biting the O-ring between the lid member and the housing, and good sealing performance between the two members can be maintained.
Further, according to the sealing device of the second aspect, the effect is remarkable in a very thin linear O-ring having a linearity of 0.4 mm to 1.6 mm.

  Furthermore, according to the sealing device of the third aspect, 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.
Furthermore, according to the sealing device of the fifth aspect, many chemical bonds are formed between the functional group of the rubber of the O-ring and the surface treatment agent, and the surface durability and non-adhesiveness can be sufficiently exhibited.
Further, according to the sealing device of the sixth aspect, since the sliding resistance is kept low, the lid can be opened and closed smoothly.

Furthermore, according to the sealing device of the seventh aspect, compared with the conventional product (compression rate 25%), the sliding resistance when the lid is opened and closed can be kept low. For this reason, it is particularly preferable in a place where opening and closing by a human hand is performed.
Furthermore, according to the sealing device of the invention described in claim 8, the protrusion of the O-ring can be kept low.

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.

The sealing device provided on the lid member of the electronic device receives 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. The housing 3 is provided with an annular inner peripheral surface 31 in sealing contact with the O-ring 2.
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 O-ring 2 is set in a range where the inner diameter extension rate is 10 to 30% and is mounted in the groove portion 12 provided on the outer peripheral surface 11.
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.
Here, the inner diameter extension rate is a value obtained by dividing the value obtained by subtracting the inner diameter d in the free state before the O-ring 2 is mounted from the bottom diameter D of the groove 12 by the inner diameter d.
The wire diameter of the O-ring 2 used here is in the range of 0.4 mm to 1.6 mm.
And when such a thin linear O-ring 2 was attached to the groove 12, the possibility of partial sagging was particularly great due to its familiarity.
In addition, the possibility of this sagging is remarkable in the middle portion in the longitudinal direction of the groove 12 provided on the rectangular outer peripheral surface.

  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, the surface of the O-ring 2 is treated with a reactive surface treatment agent or treated with a satin finish.
As a result, when the O-ring 2 is mounted in the groove 12, the sliding resistance when the lid member is opened and closed can be lowered, and the O-ring can be prevented from being twisted.
Moreover, since the familiarity is improved, 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 is bonded to a silicon atom,
Triethylsilyl isocyanate
[(C2H5) 3SiNCO]
3 NCO groups bonded to the silicon atom,
Butoxysilane triisocyanate
[C4H9OSi (NCO) 3]
Etc. 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.
Further, the compression rate of the O-ring 2 is preferably 5 to 20% in order to ensure good sealing performance.
Since the compression rate is kept low compared to the conventional product (compression rate 25%), the sliding resistance when the lid is opened and closed can be kept low.
For this reason, the lid can be easily opened and closed even by the hand of a younger person or a child with weak power.
Further, when the compression rate is 5% or less, sufficient sealing performance cannot be exhibited.
The rectangular peripheral surface 11 may have an arc-shaped portion 111.

  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 a sealing device. It is AA half sectional drawing of FIG. It is a fragmentary sectional view of the sealing device concerning a prior art.

Explanation of symbols

1 Lid member 2 O-ring 3 Housing 11 Arc-shaped portion 12 Groove portion 13 Convex portion

Claims (8)

  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 device 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 O-ring (2) is A sealing device characterized in that the inner diameter elongation rate is set in a range of 10 to 30% and is mounted in the groove (12).   The sealing device according to claim 1, wherein the O-ring (2) has a wire diameter of 0.4 mm to 1.6 mm.   The sealing device according to claim 1 or 2, wherein the hardness of the O-ring (2) is JIS A 50 to 70 °.   The sealing device according to any one of claims 1 to 3, wherein the surface of the O-ring (2) is coated.   The sealing device according to claim 4, wherein the coating treatment is treated with a reactive surface treatment agent.   The sealing device according to any one of claims 1 to 3, wherein a surface of the O-ring (2) is treated with a satin finish.   The sealing device according to any one of claims 1 to 6, wherein a compression rate of the O-ring (2) is 5 to 20%.   The sealing device according to any one of claims 1 to 7, wherein the peripheral surface (11) has an arcuate portion (111).

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