JP2010174982A - Gasket structure and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gasket structure free from adhesion peeling between a seal object substrate and a gasket in molding in a simple structure, and a method for effectively manufacturing the same. <P>SOLUTION: In the gasket structure 1 having a rubber-made gasket 3 integrally fixed to a predetermined position of a seal object substrate 2 through an adhesive layer 4 through vulcanization molding, the gasket 3 includes a gasket body 3a having a bead-like continued shape having a mountain-like section, an injection part 3c of rubber material in molding, provided in an appropriate position near a side of the gasket body 3a, and an inflow connection part 3b of rubber material connecting the injection part 3c to the basket body 3a. A connecting part 3d between the injection part 3c and the inflow connection part 3b is formed in a shape inclined toward the gasket body 3a side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gasket structure in which a rubber gasket is integrally fixed to a predetermined portion of a base material to be sealed through an adhesive by vulcanization molding, for example, the entire periphery of a separator constituting a fuel cell stack and a medium opening The present invention relates to a gasket structure in which a gasket is integrally provided around a portion, or a gasket structure in which a cover and a gasket in a hard disk device or the like are integrated, and a method for manufacturing the same.

  As described above, examples of the gasket structure in which the base material to be sealed and the gasket are integrated include the prior arts disclosed in Patent Documents 1 to 4. 7 and 8 conceptually show an example of such a gasket structure and a manufacturing method thereof. 7A is a plan view showing a part of the gasket structure in which the base material and the gasket are integrated, FIG. 7B is a cross-sectional view taken along the line DD in FIG. c) has shown the EE arrow directional cross-sectional view in (a). FIG. 8 is a sectional view of a portion corresponding to FIG. 7C, which shows how to manufacture the gasket structure by molding.

  The gasket structure 50 shown in FIG. 7 is an annular rubber gasket that follows the shape of the annular groove 51a through the adhesive layer 52 at the bottom of the annular groove 51a formed in a predetermined portion of the base material 51 to be sealed. 53 is integrally fixed by vulcanization molding. The gasket 53 includes a gasket main body portion 53a that is continuous in a bead shape having a cross-sectional angle, a rubber inflow connection portion 53b that protrudes from an appropriate position at the bottom of the gasket main body portion 53a, and a rubber material in the inflow connection portion 53b. And an injecting portion 53c of rubber material at the time of molding, which remains as a burr mark on the inflow base portion (may not be visible).

  An example of manufacturing the gasket structure 50 as shown in FIG. 7 by molding a rubber material will be described with reference to FIG. A mold 60 shown in FIG. 8 is applied to an injection molding method or a transfer molding method, and includes a lower mold 61 and an upper mold 62. The lower mold 61 includes a cavity 61 a that can accommodate the base material 51. The upper mold 62 includes an annular cavity 62a formed so as to correspond to the shape of the gasket 53 and an injection gate 62b of unvulcanized rubber material 53R, and further connects the injection gate 62b and the cavity 62a. An inflow passage 62c for the unvulcanized rubber material 53R is formed to communicate with the cavity 62a. One or more such injection gates 62b and inflow passages 62c are provided along the outer side of the annular cavity 62a.

  In the mold 60, first, the base 51 is placed in a cavity 61a formed in the lower mold 61, and an adhesive 52R is applied to the bottom of the annular groove 51a in the base 51, and then the upper mold is applied. The mold 62 is clamped to the lower mold 61. Then, an unvulcanized rubber material 53R is injected into the injection gate 62b from an injection device (not shown), and the injected rubber material 53R reaches the inside of the cavity 62a through the inflow path 62c by the injection pressure. When the cavity 62a is sufficiently filled with the rubber material 53R, the pressure maintaining state is maintained and the rubber material 53R is vulcanized. This vulcanization is performed by heating the mold or by heat held by the unvulcanized rubber material 53R, and the curing of the adhesive 52R is promoted along with this vulcanization. Thereafter, when the mold is removed and the rubber material remaining on the injection gate 62b is cut off, the gasket 53 is integrally fixed to the bottom of the annular groove 51a of the base material 51 to be sealed via the adhesive layer 52 as shown in FIG. A gasket structure 50 is obtained.

JP-A-4-144726 Japanese National Patent Publication No. 8-507482 JP 2004-76877 A JP 2008-1002 A

  By the way, in the molding method as described above, since the installation space of the injection gate 62b is limited due to the shape characteristics of the molding object, the injection direction of the unvulcanized rubber material 53R is set near the cavity 62a. It is necessary to make it perpendicular to the material 51 and to make the cross-sectional area of the injection port portion very small. Therefore, immediately below the injection gate 62b, the injection pressure of the vertical and high-pressure unvulcanized rubber material 53R is applied on the sealing target substrate 51 to which the adhesive 52R is applied. Due to the shear stress of the injection pressure, the adhesive 52R in the vicinity of the injection gate 62b is peeled off, and the unvulcanized rubber material 53R in this portion may be deformed and vulcanized. In particular, since the injection gate 62b and the cavity 62a are close to each other, such a peeling or deformation phenomenon extends to the bonded portion between the gasket main body portion 53a after the vulcanization molding and the base material 51 to be sealed. It will also affect the. In FIG. 7A, a range where the adhesiveness in the vicinity of the injection portion 53c is not sufficient is indicated by a two-dot chain line a.

  In Patent Document 1, when a rubber-like elastic lip (gasket) is vulcanized and molded on the inner peripheral surface of a hole provided in a plate, the rubber material is injected from the direction toward the inner peripheral surface. It is disclosed that the lip portion is formed on the surface so as to protrude in the inner diameter direction of the hole. This prior art does not form a gasket on the plate surface of the plate via an adhesive, and the installation position of the injection gate is not restricted as described above. There will be no problem due to agent peeling.

  Patent Document 2 relates to a panel assembly provided with a gasket on a glass panel having a primer layer. In FIG. 15 and FIG. 17 and the related description, a mold cavity (cavity) is formed from a radial runner. It is described that a gasket is formed on a primer by injecting a polymer (resin) through a passage of an injection material having a gate slope toward the surface. In this case, since the target is an embedded panel of a vehicle or a building, the molding die itself is large, and there is no restriction on the space for forming the passage of the injection material and the gate slope, so that The problem is not assumed.

  Patent Document 3 and Patent Document 4 are not intended to solve the above-mentioned specific problems. In particular, in Patent Document 4, the opening of the injection gate has a long diameter along the longitudinal direction of the gasket in view of the fact that the injection property of the rubber material is deteriorated because the injection gate is close to the gasket. It does not mention the problem of adhesion in the vicinity of the gate.

  The present invention has been made in view of the above circumstances, and provides a gasket structure that has a simple structure and does not have adhesive separation between the base material to be sealed and the gasket at the time of molding, and an effective manufacturing method thereof. It is aimed.

  A gasket structure according to a first aspect of the present invention is a gasket structure in which a rubber gasket is integrally fixed to a predetermined portion of a base material to be sealed via an adhesive layer by vulcanization molding, and the gasket has a mountain-shaped cross section. A gasket main body portion continuous in a bead shape, an injection portion of a rubber material at the time of molding provided at an appropriate position in the vicinity of the side portion of the gasket main body portion, and an inflow connecting portion of a rubber material connected from the injection portion to the gasket main body portion; The connecting portion between the injection portion and the inflow connecting portion is inclined to the gasket main body portion side.

  In the gasket structure of the present invention, the connecting portion may be cut after the molding. The predetermined portion may be a bottom portion of an annular groove formed in the sealing target base material.

  A method for manufacturing a gasket structure according to a second aspect of the present invention includes a cavity corresponding to a gasket shape including a gasket main body portion in which a cross-section is formed in a bead shape with a cross-section formed by applying an adhesive to a predetermined portion of a base material to be sealed. After placing the mold, unvulcanized rubber material is injected into the cavity from the injection gate formed in the mold so that the rubber material becomes the gasket shape at a predetermined portion of the base material to be sealed. A method of manufacturing a gasket structure for integral vulcanization molding, wherein the cavity of the mold is provided with a rubber material inflow path from a side of the injection gate to a portion corresponding to the gasket body, The injection gate is composed of a vertical portion with respect to the base material to be sealed, and a small-diameter injection port that is inclined to a portion corresponding to the gasket main body portion on the front side of the vertical portion and connected to the inflow path, The unvulcanized rubber material is injected from the injection gate in a state in which the unvulcanized rubber material is inclined toward the portion corresponding to the gasket main body with respect to the adhesive application surface on the base material to be sealed. .

  In the gasket structure according to the first invention, a rubber gasket is integrally fixed to a predetermined portion of the base material to be sealed via an adhesive layer by vulcanization molding. The base material to be sealed and the gasket will not be separated even in the flow of transportation or the like. The gasket structure is brought into an assembly plant such as a fuel cell or a hard disk device as it is, and is fastened integrally with another seal target member, so that the seal target base material and the other seal target member are interposed. A rubber gasket is clamped in a compressed state, and a seal is made between them. Therefore, in the above assembly plant, the work of interposing a separately prepared gasket between the sealing target members is not required, and the efficiency of the assembling work is improved.

  Further, in the gasket structure of the present invention, since the connecting portion between the rubber material injection portion and the rubber inflow connecting portion at the time of molding is inclined to the gasket body portion side, The rubber material at the time of molding flows obliquely with respect to the base material to be sealed and is vulcanized and fixed. That is, during molding, a vertical and high pressure rubber material injection pressure is not applied to the adhesive-coated surface on the sealing target base material, so that phenomena such as adhesive peeling and rubber deformation do not occur. Moreover, this phenomenon does not reach the gasket main body, and has a sufficient sealing property. Therefore, even when the width of the predetermined portion of the base material to be sealed to which the gasket is to be fixed is limited, a gasket structure having excellent sealing performance can be obtained.

  It is good also as what cut | disconnected the said connection part after shaping | molding. That is, the connecting portion is an inclined shape and is not integrally bonded to the base material to be sealed and does not have a sealing function. When the predetermined portion is the bottom of the annular groove formed in the base material to be sealed, stable fixation and integration between the gasket and the base material to be sealed is achieved. In this case, the width of the predetermined portion is limited by the width of the annular groove, but this gasket structure is not affected by the molding due to such limitation and has a good sealing function. is there.

  According to the method for manufacturing a gasket structure according to the second invention, after applying an adhesive to a predetermined portion of the base material to be sealed, the unvulcanized rubber material is put into the cavity from the injection gate formed in the mold. Since the rubber material is integrally vulcanized and molded so as to form the gasket shape at a predetermined portion of the base material to be sealed, the curing of the adhesive is promoted together with the vulcanization of the rubber material, A rubber gasket is firmly fixed and integrated at a predetermined portion of the base material to be sealed.

  In addition, a mold injection gate includes a vertical portion with respect to the base material to be sealed, and a small-diameter injection port that is inclined to a portion corresponding to the gasket main body portion on the front side of the vertical portion and connected to the inflow passage Therefore, the injection gate can be formed even if the installation space of the injection gate is limited. And, since the injection of the unvulcanized rubber material from the injection gate is performed in a state where it is inclined to the side corresponding to the gasket main body part with respect to the adhesive application surface on the base material to be sealed, Phenomena such as peeling of the adhesive and deformation of the rubber due to the injection pressure of the high-pressure unvulcanized rubber material being applied vertically to the adhesive application surface do not occur. Therefore, a gasket structure that is firmly fixed and integrated with the base material to be sealed and has excellent sealing properties can be obtained.

  In the present invention, as the rubber material constituting the gasket, any rubber material selected from NBR, H-NBR, ACM, AEM, FKM, EPDM, VMQ and the like is desirably employed. In addition, as the adhesive constituting the adhesive layer, a thermosetting adhesive is used, and specifically, an epoxy-based, phenol-based, coupling agent-based, polyimide-based, or rubber-glue-based adhesive is desirable. Adopted. This adhesive is cured at the vulcanization temperature at the time of vulcanization molding of the rubber material, and causes a chemical reaction at the interface between the rubber material and the base material to be sealed at the time of curing, so that both the bonded members are firmly integrated. To do.

It is a top view which shows the example which applied the gasket structure of this invention to the separator of the fuel cell. It is an enlarged view of the A section in FIG. (A) is the BB arrow directional cross-sectional view in FIG. 2, (b) is CC sectional view taken on the line in FIG. It is sectional drawing which shows the point which manufactures the gasket structure body by shaping | molding by the part corresponding to FIG.3 (b). It is a figure similar to FIG. 4 which shows the other point which manufactures a gasket structure by shaping | molding. (A) (b) (c) is a figure similar to the enlarged part of FIG. 4 of other embodiment of the metal mold | die used for manufacture of a gasket structure. The example of the conventional gasket structure is shown, (a) is a top view which shows a part of the gasket structure, (b) is DD sectional view taken on the line in (a), (c) is (a) The EE arrow directional cross-sectional view in is shown. It is sectional drawing which shows the point which manufactures the conventional gasket structure by a shaping | molding by the part corresponding to FIG.7 (c).

  Embodiments of the present invention will be described below with reference to the drawings. A gasket structure 1 shown in FIG. 1 is a separator for a fuel cell, and is combined with a polymer electrolyte membrane (not shown) to constitute a fuel cell configuration stack (not shown). The separator as the gasket structure 1 uses a carbon plate or a metal plate or the like as a base material 2 to be sealed, and is made of rubber via a bonding agent layer (see FIG. 3) 4 at a predetermined portion of the base material 2 to be sealed. The gasket 3 is integrally fixed. The base material 2 to be sealed includes a plurality of openings 2a for circulating a medium such as refrigerant, hydrogen, oxygen, etc. at appropriate positions. An annular groove (around the entire periphery of the base material 2 to be sealed and the openings 2a ... 2b) is formed. The bottom of the annular groove 2b is a predetermined portion to which the gasket 3 is integrally fixed. When the gasket 3 is integrally fixed to the annular groove 2b, a plurality of the stacks are tightened to form a fuel cell. Thus, leakage of the medium is prevented.

  The rubber gasket 3 includes a gasket main body portion 3a continuous in a bead shape having a cross-sectional angle, a rubber inflow connecting portion 3b at the time of molding projecting from an appropriate position at the bottom of the gasket main body portion 3a, and the inflow And a rubber material injection portion 3c at the time of molding which remains as a burr mark on the inflow base portion of the rubber material in the connecting portion 3b (which may not be visible). And as shown in FIG. 3, the connection part 3d of this injection | pouring part 3c and the inflow connection part 3b is made into the shape which inclines in the curve shape to the said gasket main-body part 3a side. You may remove this connection part 3d from the broken-line part b of FIG.3 (b) after shaping | molding.

  Here, a method of manufacturing the gasket structure 1 by molding will be described with reference to FIG. In FIG. 4, the mold 5 used in this production is applied to the injection molding method or the transfer molding method as described above, and forms a lower mold 6, an upper mold 7 and a part of the upper mold 7. The core mold 7A is assembled as described above. The lower mold 6 includes an annular cavity 6 a that can accommodate the sealing target substrate 2. The upper mold 7 includes an annular cavity 7a formed to correspond to the shape of the gasket 3, and an injection gate 7b of unvulcanized rubber material 3R. Further, the injection mold 7b and the cavity 7a The inflow path 7c of the unvulcanized rubber material 3R that connects the two is formed so as to communicate with the cavity 7a. The core mold 7A constitutes a split mold as a part of the upper mold 7. In the combined state of the upper mold 7 and the core mold 7A, the injection gate 7b is connected to the base material 2 to be sealed. A vertical portion 7ba formed in a vertical shape, and a small-diameter injection port 7bb which is bent in an inclined state toward a portion corresponding to the gasket main body portion 7a on the front side of the vertical portion 7ba and connected to the inflow passage 7c Is provided. One or more such injection gates 7b and inflow passages 7c are provided along the outer side of the annular cavity 7a.

  In the mold 5, first, the base material 2 to be sealed is disposed in a cavity 6 a formed in the lower mold 6, and an adhesive 4 </ b> R is applied to the bottom of the annular groove 2 b of the base material 2 to be sealed. The upper mold 7 in which the core mold 7A is assembled to the lower mold 6 is clamped together. Then, the unvulcanized rubber material 3R is injected into the injection gate 7b from an injection device (not shown). The injected rubber material 3R has a small-diameter injection port 7bb and an inflow passage connected to the front portion of the injection gate 7b by an injection pressure so as to incline to the portion corresponding to the gasket main body 7a. It goes into the cavity 7a via 7c. In FIG. 4, the injection state of the rubber material 3R at this time is indicated by a line L. Thus, in the vertical portion 7ba of the injection gate 7b, the rubber material 3R is injected in a state perpendicular to the base material 2 to be sealed, squeezed by the injection port 7bb, and regulated by the shape of the injection port 7bb. In the state where the direction is changed, the air flows from the inflow path 7c into the cavity 7a.

  When the rubber material 3R flows into the inflow path 7c from the vertical portion 7ba through the injection port 7bb, the vertical injection pressure of the rubber material 3R is attenuated by the curved inner wall portion of the injection port 7bb. Therefore, when flowing into the cavity 7a from the inflow path 7c, the shear stress due to the injection pressure applied to the adhesive 4 applied to the base material 2 to be sealed is weakened, and the adhesive 4 is peeled off. The unvulcanized rubber material 3R is not deformed and vulcanized. In this case, even if the length of the inclined portion in the injection port 7bb is sufficiently shorter than the length of the vertical portion 7ba, the above-described attenuation effect of the injection pressure works, so even if the installation space of the injection gate 7b is limited, this Such an injection gate 7b can be formed, which is particularly effective.

  When all the cavities 7a are sufficiently filled with the unvulcanized rubber material 3R, the pressure is maintained and the rubber material 3R is vulcanized. This vulcanization is performed by heating the mold or by heat held by the unvulcanized rubber material 3R, and the curing of the adhesive 4R is promoted along with this vulcanization. After that, when the mold is removed and the rubber material remaining on the injection gate 7b is cut away, the bottom of the annular groove 2b of the base material 2 to be sealed is made of rubber via the adhesive layer 4 as shown in FIGS. The gasket structure 1 to which the gasket 3 is integrally fixed is obtained. As described above, the obtained gasket structure 1 is free from phenomena such as peeling of the adhesive layer 4 and deformation of the rubber in the gasket 3 portion, and has a highly reliable sealing property.

  In the manufacturing method of the gasket structure shown in FIG. 5, molding is performed using the upper mold 7 in which the portion corresponding to the core mold as described above is integrated. In this case, demolding is performed by opening the mold so as to deform the rubber material remaining in the connecting portion 3d and the injection gate 7b, or by cutting them so that they are shredded simultaneously with the mold opening. Since other configurations are the same as those in FIG. 4, common portions are denoted by the same reference numerals, and descriptions thereof are omitted.

  6 (a), 6 (b) and 6 (c) show another embodiment of a mold used when the gasket structure 1 is manufactured by molding. Also in these examples, the injection gate 7b is inclined to the portion corresponding to the gasket main body portion of the cavity 7a on the vertical portion 7ba perpendicular to the base material 2 to be sealed and on the front side of the vertical portion 7ba. And a small-diameter injection port 7bb connected to the inflow passage 7c. Due to the shape characteristic of the injection gate 7b, there is no reliability such as peeling of the adhesive layer 4 or deformation of rubber in the gasket 3 portion. A gasket structure 1 having high sealing performance is obtained. The various examples shown are appropriately selected and adopted as design matters depending on the workability of the mold, the degree of attenuation of the injection pressure of the unvulcanized rubber material 3R, etc. It is possible to adopt as well. Also in these examples, as in the example of FIG. 5, molding may be performed using an upper mold in which a portion corresponding to a core mold is integrated. Since other configurations are the same as described above, common portions are denoted by the same reference numerals, and descriptions thereof are omitted.

  In the above embodiment, the predetermined portion where the gasket 3 of the base material 2 to be sealed is integrally fixed is the bottom of the annular groove 2b. However, the flat portion having no restriction on the effective width without such an annular groove. It may be. Moreover, although the example applied to the separator of the fuel cell has been described, the present invention can also be applied to a hard disk device and other devices that are provided for distribution in a state where the sealing target base material and the gasket are integrally fixed. it can.

DESCRIPTION OF SYMBOLS 1 Gasket structure 2 Base material to be sealed 2b Annular groove (predetermined part)
DESCRIPTION OF SYMBOLS 3 Gasket 3a Gasket body part 3b Inflow connection part of rubber material 3c Injection part of rubber material 3d Connection part 3R Unvulcanized rubber material 4 Adhesive layer 4R Uncured adhesive 5 Mold 7 Upper mold (mold)
7a Cavity 7b Injection gate 7ba Vertical portion of injection gate 7bb Injection gate injection port 7c Inflow path 7A Core mold (mold)

Claims (4)

A gasket structure in which a rubber gasket is integrally fixed to a predetermined portion of a base material to be sealed through an adhesive layer by vulcanization molding,
The gasket includes a gasket main body portion connected in a bead shape having a cross-sectional mountain shape, an injection portion of a rubber material at the time of molding provided in a position near a side portion of the gasket main body portion, and a rubber connected from the injection portion to the gasket main body portion. A gasket structure comprising a material inflow connecting portion, and a connecting portion between the injection portion and the inflow connecting portion is inclined toward the gasket main body. The gasket structure according to claim 1,
The gasket structure according to claim 1, wherein the connecting portion is cut after the molding. In the gasket structure according to claim 1 or 2,
The gasket structure according to claim 1, wherein the predetermined portion is a bottom portion of an annular groove formed in a base material to be sealed. After applying adhesive to a predetermined part of the base material to be sealed and placing a mold with a cavity corresponding to the gasket shape including a gasket body part with a cross-sectionally continuous bead shape, it is formed on the mold A method for manufacturing a gasket structure in which an unvulcanized rubber material is injected into a cavity from the injection gate thus formed, and a rubber material is integrally vulcanized and molded into a predetermined portion of the base material to be sealed so as to have the gasket shape. ,
The cavity of the mold is provided with a rubber material inflow path from the injection gate to a portion corresponding to the gasket main body on the side, the injection gate including a vertical portion with respect to the base material to be sealed, It consists of a small-diameter injection port that is inclined to the side of the portion corresponding to the gasket main body portion and connected to the inflow path on the front side of the vertical portion,
Injecting the unvulcanized rubber material from the injection gate is performed in a state in which the unvulcanized rubber material is inclined toward the portion corresponding to the gasket main body with respect to the adhesive application surface on the base material to be sealed. Manufacturing method of gasket structure.

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