JP2001056055A - Framed gasket and manufacture therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To seal a portion required to be sealed inside a cover body by mounting once by integrating an outer frame with an inner frame, and integrating the outer frame and inner frame with a gasket formed by an elastic body. SOLUTION: An inner frame 1b is provided on the inside of an outer frame 1a, and the outer frame 1a and the inner frame 1b are integrated with each other by a bar-like body 1c. A gasket 2a formed by an elastic body is secured to the side of the outer frame 1a, a gasket 2b is secured to the side of the inner frame 1b, and the respective gaskets 2a and 2b are integrated with the outer frame 1a and the inner frame 1b. Thus, a portion required to be sealed inside the cover body can be sealed by mounting once, and even if the frame is manufactured by synthetic resin, the total thickness of the gaskets 2a, 2b can be kept from being increased to reduce the weight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gasket with a frame and a method of manufacturing the same, and more particularly, to a gasket with a frame for sealing a joint surface between a cover body and a main body of a lightweight electronic device, for example, a hard disk device of a computer. It relates to the manufacturing method. The gasket with a frame of the present invention can be installed even in a narrow gap, and the inside of the cover body can be sealed with a single installation without using a plurality of gaskets, so that it can be installed in a robot in an automated line or the like. It can be applied to the technology of completely sealing the installed hard disk device from water or air.

[0002]

2. Description of the Related Art In recent years, the development of electronic devices has been remarkable. These electronic devices use integrated circuits using semiconductors and are printed and wired on a substrate.
The weight has been reduced. These electronic devices dislike moisture and dust. Therefore, the sealing performance of the gasket that seals the joint surface between the box-shaped main body containing these integrated circuits and the cover body depends on the performance and durability of the electronic devices. Is an important factor for

[0003] Therefore, usually, a gasket is sandwiched between the joint surfaces of a box body and a cover body containing these integrated circuits and the like, and the gasket is fastened with mounting bolts or the like to be hermetically integrated. A high-density urethane foam material was used as the material. The urethane foam material is foamed into a thin sheet shape, and an adhesive tape is stuck to the sheet and punched into a desired shape in many cases. However, since such a gasket is soft, it has been difficult to install the gasket at a predetermined position. Therefore, a foam such as a urethane foam material is heated and integrally molded on both sides of a sheet made of a resin such as polypropylene or polyethylene terephthalate, and is punched into a desired gasket shape for use [Japanese Patent No. 2507197 (Japanese Unexamined Patent Publication No. JP-A-6-89562) and JP-A-9-1839.
No. 64]. However, the resin sheet has a lower rigidity than a metal frame described later, and thus the resin sheet is likely to be displaced when the gasket is used. In order to prevent this displacement, the gasket is used by attaching it to a cover body. Further, there has been proposed a gasket in which an elastomer is fixed to both surfaces of a frame, which is manufactured by inserting a frame made of stainless steel or synthetic resin into a mold and then injection-molding an elastomer (Japanese Patent Laid-Open No. 8-28).
No. 3698). As a gasket with a frame, a gasket in which rubber such as EPDM is arranged and integrated on both surfaces of a metal frame having many small holes has been proposed (Japanese Patent Application Laid-Open No. 4-341986). In these gaskets, a frame body is used to make the gasket rigid, and the mountability to equipment is improved.

When a gasket with a frame having an elastomer fixed to both surfaces of a frame is used while being sandwiched between joint surfaces of the box and the cover, the gasket is provided at several flat portions of a predetermined height provided on the box. The cover and the cover are crushed by abutment, and the gasket where the box and the cover are not abutted is crushed, thereby sealing the box and the cover. The amount of crushing of the gasket at the place where the box and the cover do not abut is determined by the height of the flat portion provided on the box, that is, by the gap at the place where the box and the cover do not abut. . The gap for such a gasket and the width of the gap are becoming smaller year by year as the hard disk drive becomes smaller. It is difficult to design a frame having rigidity in spite of its narrow width in accordance with the narrow gap. This is because, in a framed gasket in which elastic bodies, which are gasket materials, are arranged on both sides of a rigid frame body, it is necessary to increase the thickness of the gasket to some extent in order to satisfy the sealing property together with the rigidity. In particular, when the frame is made of synthetic resin for the purpose of reducing the weight and cost of the frame, the rigidity of the synthetic resin is lower than that of metal. It was necessary to make the thickness about five times, and it was difficult to apply a frame made of synthetic resin to a narrow gap between the box and the cover. Further, in the conventional gasket with a frame, since the gasket is formed on the frame in a shape along the outer peripheral portion of the cover, a seal portion inside the cover (for example, a seal portion of a connector, etc.) Still, one or more other gaskets had to be used.

[0005]

SUMMARY OF THE INVENTION The present invention satisfies both the rigidity and the sealing performance, and it is possible to use a single mounting even for a portion requiring sealing inside the cover body without using a plurality of gaskets. It is an object of the present invention to provide a framed gasket that can be sealed.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, in the framed gasket, the frame was integrated with the outer frame and the outer frame. The outer periphery of the cover body by integrating these frame bodies and the gasket, or by integrating the gasket with the entire outer surface and part of the inner surface of the frame body. At the same time, it has been found that a portion on the inside of the cover body that requires sealing can be sealed with a single installation, and a framed gasket having desired rigidity and excellent sealing properties can be obtained. The present invention has been completed based on such findings. That is,
The present invention provides a gasket with a frame in which a frame and a gasket are integrated, wherein the frame has an outer frame and an inner frame integrated with the outer frame, and the gasket is made of an elastic body. A gasket with a frame, wherein the gasket is integrated with the outer frame and the inner frame, a gasket with a frame in which the frame and the gasket are integrated, wherein the gasket is made of an elastic material, and A gasket with a frame, wherein the gasket is integrated with the frame on the entire outer surface of the frame and a part of the inner surface of the frame, and the frame and the gasket are formed by a two-color molding method or an insert molding method. It is intended to provide a method of manufacturing a framed gasket characterized by being integrated.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the gasket with a frame of the present invention, a metal plate, a synthetic resin or the like can be used as a material for forming the frame. As the metal plate, for example, a cold-rolled steel plate, a galvanized steel plate, an aluminum / zinc alloy-plated steel plate, a stainless steel plate, an aluminum plate, an aluminum alloy plate, a magnesium plate, a magnesium alloy plate, etc. Can be selected and used. Further, a product obtained by injection-molding magnesium can also be used. From the viewpoint of corrosion resistance, a metal plate subjected to electroless nickel plating is preferable. As the electroless nickel plating method, there are known methods conventionally applied to metal materials, for example, pH 4.0 to 5.0 containing nickel sulfate, sodium hypophosphite, lactic acid, propionic acid and the like at an appropriate ratio. A method of immersing a metal plate in an electroless nickel plating bath consisting of an aqueous solution of about 0 and a temperature of about 85 to 95 ° C. can be used. Examples of the synthetic resin forming the frame include, for example, acrylonitrile styrene (AS) resin, acrylonitrile butadiene styrene (ABS) resin, styrene resins such as polystyrene and syndiotactic polystyrene, polyethylene, polypropylene, ethylene-propylene copolymer and the like. Olefin resin such as polypropylene composite, polyamide resin such as nylon, polyethylene terephthalate,
Examples include polyester resins such as polybutylene terephthalate, modified polyphenylene ether, acrylic resins, polyacetals, polycarbonates, liquid crystal polymers, and thermoplastic resins such as polyphenylene sulfide (PPS), which may be appropriately selected from these. As the liquid crystal polymer, a thermotropic liquid crystal polymer is preferable, and specifically, a polycarbonate liquid crystal polymer,
Polyurethane liquid crystal polymer, polyamide liquid crystal polymer, polyester liquid crystal polymer, and the like. These resins may be used alone or in combination of two or more. In the present invention, polypropylene and a polypropylene composite are preferred because they can be fused with a styrene-based elastomer having excellent sealing properties and low hardness.

As the elastic body forming the gasket, vulcanized rubber such as butyl rubber or EPDM rubber, thermoplastic elastomer, or the like can be used. As the thermoplastic elastomer, for example, styrene-based, olefin-based,
A thermoplastic elastomer such as urethane or ester can be used. In particular, a copolymer comprising at least one polymer block mainly composed of a vinyl aromatic compound and at least one polymer block mainly composed of a conjugated diene compound can be used. Those containing a polymer thermoplastic elastomer are preferably used. More specifically, for example, a block copolymer of crystalline polyethylene and ethylene / butylene-styrene random copolymer obtained by hydrogenating a block copolymer of polybutadiene and butadiene-styrene random copolymer, A block copolymer of polybutadiene and polystyrene, and a block copolymer of polyisoprene and polystyrene, or obtained by hydrogenating a block copolymer of polybutadiene or an ethylene-butadiene random copolymer and polystyrene, for example, Diblock copolymer of crystalline polyethylene and polystyrene, styrene
Ethylene / butylene-styrene triblock copolymer (SEBS), styrene-ethylene / propylene-styrene triblock copolymer (SEPS), among others, styrene-ethylene / butylene-styrene block copolymer or styrene-ethylene / Propylene-styrene block copolymer. These elastomers may be used alone or in combination of two or more. The combination of the thermoplastic resin of the frame and the thermoplastic elastomer which is the material of the gasket is not particularly limited, but a combination of an olefin resin and a styrene elastomer or an olefin elastomer, a nylon or ABS resin and a urethane elastomer And the like.

An antistatic property can be imparted to the thermoplastic resin or thermoplastic elastomer by adding a filler capable of imparting conductivity. By imparting antistatic properties, it is possible to prevent dust or dirt from adhering to the gasket or the cover body in the manufacturing process of the cover with the gasket. Examples of the filler capable of imparting conductivity include conductive powders such as metal powder and metal fiber such as iron, stainless steel and aluminum, carbon black and carbon fiber, polyalkylamine, alkylsulfonate, and the like.
Antistatic agents such as quaternary ammonium chloride and alkyl betaine can be used. The amount of filler to be added to the thermoplastic resin or the thermoplastic elastomer may be an amount such that the volume resistivity of the thermoplastic resin or the thermoplastic composition elastomer when the filler is added is 1 × 10 ⁸ Ωcm or less. preferable. Further, when the cover body is required to have an electromagnetic wave shielding property, the above volume resistance value is 1 × 10 ² Ω.
cm or less. In the case of a thermoplastic elastomer, J
The IS-A hardness is preferably 80 degrees or less, particularly preferably 10 to 50 degrees. Further, the thermoplastic resin or the thermoplastic elastomer may include, as reinforcing materials, inorganic fibers such as glass fibers and carbon fibers, inorganic fillers such as mica and talc, whiskers such as potassium titanate, and the like, which impair the effects of the present invention. It can be added in a range that does not exist.

In the framed gasket of the present invention, when the frame is formed of a synthetic resin, the gasket can be fixed to the side surfaces of the outer frame and the inner frame. , It can be installed in a narrow gap. FIG. 1 is a perspective view showing an example of a framed gasket of the present invention, and FIG. 2A is an enlarged view of a cross section taken along line AA of FIG. As shown in FIGS. 1 and 2A, the gasket with a frame is formed by fixing a gasket 2a to a side surface of an outer frame 1a and fixing a gasket 2b to a side surface of an inner frame 1b. the total thickness of the gasket 2a and 2b be made of synthetic resin (see FIG. 2 (a) are shown in t ₂₎ without increasing the light in weight, the outer frame member 1a and the inner frame member 1b
The shape of the gaskets 2a and 2b can be formed into a shape desired to satisfy the sealing performance. This gasket with a frame is provided without using a plurality of gaskets by providing an inner frame 1b inside an outer frame 1a and integrating the outer frame 1a and the inner frame 1b with a rod 1c. The inside of the body can be sealed with a single application. The gasket with a frame shown in FIGS. 1 and 2A has a total thickness of the gasket 2a and the gasket 2b (FIG. 2).
Indicated by t ₂ in (A)) but indicates the case of the same, if the clearance of the seal portion is different can be the total thickness of the total thickness and the gasket 2b of the gasket 2a different. In addition, by using a cross-sectional shape as shown in FIG. 2B, it can be used in a stepped portion. In the caged gasket of the present invention, (see w ₁ and w ₃ in FIG. 2 (A)) thickness of the frame (see t ₁ in FIG. 2 (A)) and a width,
The total thickness of the gasket (see w ₂ and w ₄ of FIG. 2 (A)) (FIG. 2 (see t ₂ of A)) and the width is properly selected due to the caged gasketing applications, sufficient rigidity From the viewpoint of obtaining, it is preferable that the thickness of the frame is 0.1 mm or more.
When the thickness of the frame is 0.1 to 1.2 mm, the width of the frame is 0.1 mm.
5 to 5.0 mm, preferably 1.0 to 3.0 mm, the total thickness of the gasket is 0.8 to 2.5 mm, preferably 1.2 to 1.8 mm,
The width of the gasket is 0.5-2.5 mm, preferably 0.8-1.5.
It can be 5 mm. Further, the gasket with a frame according to the present invention may have a shape shown in FIG. The gasket with a frame shown in FIG. 3 has a configuration in which the gasket with a frame shown in FIG. 1 does not have the inner frame 1b and the rod-shaped body 1c, and the gasket 2b is fixed to the inner surface of the frame 1d. In the gasket with a frame shown in FIG. 3, the same parts as those in the gasket with a frame shown in FIG. 1 can have the same dimensions.

[0011] The integration of the frame and the gasket is performed when the material forming the gasket is a thermoplastic elastomer.
This is accomplished by shaping the gasket into a frame by injection molding. When the material of the frame is a thermoplastic resin and the gasket material is a thermoplastic elastomer, the frame is formed by joining the thermoplastic resin and the thermoplastic elastomer. Specifically, a two-color molding method or insert molding is used. This is done by a method such as the law. In the two-color molding method, first, the thermoplastic resin forming the frame, by a dedicated injection molding machine, melt injection molding in a mold to obtain a frame of a thermoplastic resin molded product having a fitting portion, After the molded product is solidified, the thermoplastic elastomer excellent in the fusion property with the thermoplastic resin is melt-injected and molded by a dedicated injection molding machine, and a portion other than the fitting portion of the frame of the thermoplastic resin molded product is used. By forming a gasket portion composed of a thermoplastic elastomer layer at the portion (1), a gasket with a frame in which the thermoplastic resin and the thermoplastic elastomer layer formed on the side surface thereof are integrally compounded is obtained. Such two-color molding method has high production efficiency,
The framed gasket can be manufactured at low cost. On the other hand, in the insert molding method, a frame having a predetermined shape is prepared by a known various molding method using a thermoplastic resin in advance, and the frame is placed in a mold. Next, the thermoplastic elastomer is melt-injected and molded by an injection molding machine to form a thermoplastic elastomer layer on a part of the frame, whereby the frame and the thermoplastic elastomer formed on the side surface thereof are formed. A framed gasket that is integrally integrated is obtained.

In the framed gasket of the present invention, when the frame is made of synthetic resin, the shape may be such that the gasket is fixed to the side surface of the frame.
This is only possible when the frame made of synthetic resin and the gasket made of the elastic body are integrated by fusion, and it is possible to use a gasket with a frame using a metal frame or a resin sheet and foam. It is difficult to realize with such a punched product. Further, since a metal material is not used, a rust-proofing step is not required and the weight can be reduced, so that the hard disk drive can be suitably used. Furthermore, since a synthetic resin is used, it is possible to use one mold inexpensively and efficiently,
It is possible to manufacture the frame with high precision and to recycle the synthetic resin. Examples of the material for forming the cover or box in which the framed gasket of the present invention is used include the above-mentioned thermoplastic resins and other various synthetic resins, and other metals or alloys such as aluminum, iron, stainless steel, and magnesium. Can be used.

[0013]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 A framed gasket shown in FIGS. 1 and 2 was produced by a two-color molding method as follows. This gasket with a frame has a size of 95 mm × 140 mm, a thickness (t ₁ ) of the outer frame 1 a, the inner frame ₁ b and the rod 1 c of 0.7 mm, and a width (w) of the outer frame 1 a and the inner frame 1 b. ₁ and w ₃ ) are 2.0 mm, the total thickness (t ₂ ) of the gaskets 2 a and 2 b is 1.4 mm, the width (w ₂ and w ₄ ) of the gaskets 2 a and 2 b is 1.0 mm, and the outside of the inner frame 1 b. The diameter (w ₅ ) is 10.0 mm, and the width (w
₆ ) is 2.0 mm. As the thermoplastic resin forming the frame 1, polypropylene (Sumitomo Chemical Co., Ltd.)
(Noblen Y101). The thermoplastic elastomer forming the gasket is composed of 100 parts by weight of SEPS having a number average molecular weight of 100,000 and a styrene content of 30% by weight,
Paraffin oil having a kinematic viscosity at 40 ° C. of 380 mm ² / sec [manufactured by Idemitsu Kosan Co., Ltd., trade name: Diana Process Oil PW380, weight average molecular weight 750] 15
It was prepared by kneading 0 parts by weight and 12.5 parts by weight of polypropylene (Noblen Y101 manufactured by Sumitomo Chemical Co., Ltd.). JIS of this thermoplastic elastomer
-A hardness was 22 degrees. Using a DC60E5ASE machine manufactured by Nissei Plastics Co., Ltd. as a molding machine, the above-mentioned thermoplastic resin for a frame was melt-injected and molded into a mold under the conditions of a mold temperature of 40 ° C. and a resin temperature of 180 ° C. The weight of the obtained frame was 0.80 g. Next, the thermoplastic elastomer for gasket is melt-injected and molded into the frame under the conditions of a mold temperature of 40 ° C and a resin temperature of 230 ° C.
A framed gasket in which the frame and the gasket were integrated was produced. The weight of the obtained gasket with a frame was 1.40 g. Since the weight of the framed gasket of Comparative Example 1 described below is 2.0 g (the weight of the frame is 1.2 g), the framed gasket of Comparative Example 1 has a shape that seals only the outer periphery as in Comparative Example 1. As a result, it is possible to reduce the weight by about 35%. Further, the bending strength of the gasket with a frame was equivalent to that of the gasket with a frame of Comparative Example 1. When the gasket with a frame manufactured as described above was used by inserting it into a 1.1 mm gap between a box housing a hard disk device of a computer and a cover, sufficient sealing properties were maintained for a long period of time.

Comparative Example 1 As the frame 3, a stainless steel flat plate having a thickness of 0.13 mm was used, and the same thermoplastic elastomer as that used in Example 1 was used as the thermoplastic elastomer forming the gasket 4. The framed gasket shown in FIG. 5 was produced. In this gasket with a frame, the thickness (t ₁ ) of the frame 3 is 0.13 mm and the width (w ₁ )
Is 2.5 mm, the total thickness (t ₂ ) of the gasket 4 is 1.6 mm, and the width (w ₂ ) is 1.8 mm. This framed gasket was produced by the insert molding method as follows. The above stainless steel frame was replaced with Nissei Plastic Industry Co., Ltd.
The frame and the gasket are integrated by inserting the above-mentioned thermoplastic elastomer for gaskets into a mold attached to a TH30R5VSE machine manufactured by the company and then molding the thermoplastic elastomer for gasket at a mold temperature of 50 ° C and a resin temperature of 230 ° C. A composite gasket with a frame was prepared. In this gasket with a frame, since the frame is made of stainless steel, the weight of the gasket with the frame is 2.0 g (the weight of the frame is 1.2 g). And heavy.

[0015]

The framed gasket of the present invention satisfies both the rigidity and the sealing performance, and it is possible to use the gasket inside the cover body without using a plurality of gaskets in a single installation. It can be sealed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a framed gasket of the present invention.

FIG. 2A is a cross-sectional view of the gasket with frame shown in FIG.
It is an enlarged view of a section along a line, and (B) is an enlarged view of a section showing other shapes of a framed gasket.

FIG. 3 is a perspective view showing another example of the framed gasket of the present invention.

4 is a perspective view showing a framed gasket of Comparative Example 1. FIG.

FIG. 5 is an enlarged view of a cross section taken along line BB of the framed gasket shown in FIG.

[Description of Signs] 1a: Outer frame 1b: Inner frame 1c: Rod 1d: Frame 2a: Gasket 2b: Gasket

Claims (9)

[Claims] 1. A gasket with a frame in which a frame and a gasket are integrated, wherein the frame comprises an outer frame and an inner frame integrated with the outer frame, and the gasket comprises an elastic body. A gasket with a frame, wherein the gasket is integrated with the outer frame and the inner frame. 2. The frame is made of a synthetic resin, and the gasket is integrated with the outer frame and the inner frame by fixing the gasket to the side surfaces of the outer frame and the inner frame. The framed gasket according to claim 2, wherein 3. A gasket with a frame in which a frame and a gasket are integrated, wherein the gasket is made of an elastic material, and the gasket is formed on the entire outer surface of the frame and a part of the inner surface of the frame. A gasket with a frame characterized by being integrated with a gasket. 4. The frame according to claim 3, wherein the frame is made of a synthetic resin, and the gasket and the frame are integrated by fixing the gasket to an outer surface and an inner surface of the frame. With gasket. 5. The synthetic resin forming the frame body is a thermoplastic resin, the elastic body forming the gasket is a thermoplastic elastomer, and the integration is performed by fusing the thermoplastic resin and the thermoplastic elastomer. The framed gasket according to any one of claims 1 to 4, which is made. 6. The gasket with a frame according to claim 5, wherein the thermoplastic resin is polypropylene or a composite thereof. 7. The gasket with a frame according to claim 1, wherein the gasket with a frame is for a hard disk drive. 8. A method for manufacturing a gasket with a frame, comprising: integrating a frame and a gasket by a two-color molding method to manufacture the gasket with a frame according to any one of claims 5 to 7. 9. A method for manufacturing a framed gasket according to claim 5, wherein the frame body and the gasket are integrated by an insert molding method to manufacture the framed gasket according to claim 5.