Gasket

Abstract

To provide a gasket which enables a user to check twisting with a simpler structure.SOLUTION: A gasket 1 includes a gasket main part 10 formed by an elastic body and extending along a longitudinal axis x. The gasket main part 10 has: a first surface 11 defined at one side with respect to the longitudinal axis x; and a second surface 12 defined at the other side opposite to the one side with respect to the longitudinal axis x. The first surface 11 has a processing area 14 having irregularities different from irregularities on the second surface 12.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a gasket. [Background technology]

[0002] For example, Patent Document 1 discloses a technique for checking the twist of an O-ring. This O-ring has a ring-shaped magnet embedded around its entire circumference. After the O-ring is attached to an object, the direction of the magnetic poles of the magnet inside the O-ring is detected in the circumferential direction to check the twist of the O-ring. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-215582 Summary of the Invention [Problem to be solved by the invention]

[0004] This conventional O-ring requires a ring-shaped magnet embedded around its entire circumference, which makes manufacturing the O-ring both time-consuming and costly. Furthermore, checking for twisting of the O-ring requires additional tools such as a compass, magnet, and electrical wire. Checking for twisting also requires time and cost.

[0005] The present invention has been made in view of the above-mentioned problems, and has an object to provide a gasket that can check for twisting with a simpler configuration. [Means for solving the problem]

[0006] A gasket according to one embodiment of the present invention comprises a gasket body formed from an elastic material and extending along a longitudinal axis, the gasket body having a first surface defined on one side of the longitudinal axis and a second surface defined on the other side opposite the one side of the longitudinal axis, the first surface having a processed region with a texture different from the texture of the second surface.

[0007] In a gasket according to one aspect of the present invention, the processed region has a surface roughness different from the surface roughness of the second surface.

[0008] In a gasket according to one aspect of the present invention, the processed region is formed over the entire first surface.

[0009] In a gasket according to one aspect of the present invention, the processed region extends at least partially linearly along the longitudinal axis.

[0010] In one embodiment of the gasket of the present invention, the first surface is the surface of the gasket body on one side of an imaginary plane containing the longitudinal axis, and the second surface is the surface of the gasket on the other side of the imaginary plane.

[0011] In a gasket according to one aspect of the present invention, the processed region is formed by transferring the irregularities formed on the inner surface of a mold.

[0012] In the gasket according to one aspect of the present invention, the boundary line between the first surface and the second surface coincides with the parting line of the mold.

[0013] A gasket according to one aspect of the present invention is incorporated into a water electrolysis device or a fuel cell. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a gasket that allows twisting to be checked with a simpler configuration. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view showing a schematic structure of a gasket 1 according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. [Figure 3] 1 is an enlarged partial perspective view of a portion of a gasket 1 according to an embodiment of the present invention. [Figure 4] 1 is a cross-sectional view of a mold used to manufacture a gasket 1 according to one embodiment of the present invention. [Figure 5] FIG. 10 is a cross-sectional view of a mold showing a state in which an elastic material is filled into the mold. [Figure 6] FIG. 10 is a perspective view schematically showing the structure of a gasket 1A according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view schematically illustrating the structure of a gasket 1 according to one embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1. This gasket 1 is incorporated, for example, into a cell stack of a water electrolysis device that electrolyzes water to produce high-purity hydrogen, or into a cell stack of a fuel cell that generates electricity by chemically reacting hydrogen and oxygen. Water electrolysis devices and fuel cells are becoming larger in size in order to improve production efficiency and power generation efficiency. As these devices become larger, the overall length of the gasket 1 also increases. Therefore, this gasket 1 includes gaskets with a relatively long overall length (circumferential length) (for example, several meters). Note that the gasket 1 may be incorporated into any structure other than a water electrolysis device or a fuel cell.

[0017] The gasket 1 is made of an elastic material. Examples of elastic materials include fluororubber (FKM), ethylene propylene diene rubber (EPDM), and silicone rubber (VMQ). As shown in FIGS. 1 and 2, the gasket 1 includes a gasket body 10 that extends endlessly along a longitudinal axis x defined along the length of the gasket 1. In this example, the gasket body 10 has a circular cross-sectional shape in a cross section taken along an imaginary plane perpendicular to the longitudinal axis x. That is, the gasket body 10 is formed in a cylindrical shape with the longitudinal axis x as its central axis. However, the gasket body 10 may have other shapes other than a cylindrical shape, such as a prismatic shape. Furthermore, as is clear from FIG. 1, in this example, the gasket body 10 is formed in a rectangular shape when viewed in its entirety. However, the gasket body 10 may be formed in other shapes, such as a circular shape, when viewed in its entirety.

[0018] The gasket body 10 has a first surface 11 defined on one side of an imaginary plane P1 including the longitudinal axis x (e.g., above the longitudinal axis x), and a second surface 12 defined on the other side opposite the imaginary plane P1 (e.g., below the longitudinal axis x). In this example, the imaginary plane P1 bisects the gasket body 10. Therefore, the first surface 11 and the second surface 12 are semi-cylindrical surfaces around the longitudinal axis x. However, the imaginary plane P1 does not necessarily bisect the gasket body 10. Note that the "upper" and "lower" in the terms "upper" and "lower" do not necessarily coincide with the up and down in terms of gravity. A pair of boundary lines 13, 13 between the first surface 11 and the second surface 12 defined within the imaginary plane P1 coincide with the parting line of a mold used to manufacture the gasket 1, which will be described later.

[0019] FIG. 3 is an enlarged partial perspective view of a portion of a gasket 1 according to one embodiment of the present invention. FIG. 3 also shows a cross section of the gasket body 10 taken along an imaginary plane perpendicular to the longitudinal axis x. Referring to FIGS. 1 to 3 together, a first processed region 14 having a different unevenness from that of the second surface 12 is formed on the first surface 11 of the gasket body 10. In this example, the first processed region 14 is formed over the entire surface of the first surface 11. Meanwhile, a second processed region 15 having a different unevenness from that of the first processed region 14 of the first surface 11 is formed on the second surface 12. In this example, the second processed region 15 is formed over the entire surface of the second surface 12.

[0020] Here, "unevenness" includes unevenness formed by forming a predetermined uneven pattern by texturing, embossing, or the like, as well as surface textures including fine unevenness defined by surface roughness. In this example, the second processed region 15 of the second surface 12 has, for example, an extremely small surface roughness, while the first processed region 14 of the first surface 11 has a surface roughness that is relatively greater than the surface roughness of the second processed region 15 of the second surface 12, thereby achieving a difference in unevenness. This difference in unevenness is not limited, but may be such that the first processed region 14 and the second processed region 15 can be distinguished from each other during inspection using an automatic inspection device, visual inspection, or by touch, i.e., the first surface 11 and the second surface 12 can be distinguished from each other.

[0021] FIG. 4 is a cross-sectional view of a mold used to manufacture a gasket 1 according to one embodiment of the present invention. As shown in FIG. 4, a mold 20 is prepared for manufacturing the gasket 1. The mold 20 has, for example, a fixed lower mold 21 and a movable upper mold 22. A space 23 that matches the outer shape of the gasket 1 is formed between the lower mold 21 and the upper mold 22. In this example, the inner surface 21a of the lower mold 21 has irregularities with a first surface roughness. On the other hand, the inner surface 22a of the upper mold 22 has irregularities with a second surface roughness that is greater than the first surface roughness. The surface roughnesses of the inner surfaces 21a and 22a are set, for example, based on the difference in the grain size of the lower mold 21 and the upper mold 22 that constitute the mold 20.

[0022] The lower mold 21 and the upper mold 22 are butted against each other at parting surfaces 24, 25. In this example, the parting surfaces 24, 25 are defined along an imaginary plane P2 that bisects the space 23. Parting lines 26, 27 are defined at the boundaries between the parting surfaces 24, 25 and the space 23, respectively. FIG. 5 is a cross-sectional view of the mold showing a scene in which the mold has been filled with an elastic material. As shown in FIG. 5, a molten elastic material 28 is poured into the space 23 of the mold 20 through an injection port (not shown). The elastic material 28 is, for example, the thermoplastic elastic material described above. After the molten elastic material 28 has filled the space 23, the mold 20 is cooled. In this manner, the elastic material 28 hardens.

[0023] The hardened elastic material 28 is then removed from the mold 20. In this way, the gasket 1 is manufactured. Boundary lines 13, 13 that coincide with the parting lines 26, 27 are defined in the gasket 1. Concave and convex portions corresponding to the surface roughness of the inner surface 22a of the upper mold 22 are transferred to the first surface 11 above the boundary lines 13, 13. Similarly, concave and convex portions corresponding to the surface roughness of the inner surface 21a of the lower mold 21 are transferred to the second surface 12 below the boundary lines 13, 13. In this way, a first processed region 14 is formed on the first surface 11, and at the same time, a second processed region 15 is formed on the second surface 12. In this example, the first processed region 14 is formed on the entire surface of the first surface 11, and the second processed region 15 is formed on the entire surface of the second surface 12.

[0024] In the gasket 1 described above, the first surface 11 of the gasket body 10 has a first processing region 14 having a different unevenness from the unevenness of the second processing region 15 of the second surface 12. The first processing region 14 and the second processing region 15 are formed by transferring the unevenness of the inner surfaces 22a and 21a of the upper and lower mold 22 and 21 of the mold 20, respectively. Therefore, the first processing regions 14 and 15 are formed simultaneously with the molding of the gasket 1. Moreover, the first surface 11 and the second surface 12 of the gasket 1 can be distinguished by the difference in the unevenness of their surfaces. When such a gasket 1 is incorporated into, for example, a water electrolysis device or a cell stack of a fuel cell, the first surface 11 and the second surface 12 can be easily distinguished by the difference in unevenness. Therefore, twisting of the gasket 1 can be confirmed with a simpler configuration.

[0025] FIG. 6 is a perspective view schematically illustrating the structure of a gasket 1A according to another embodiment of the present invention. In this gasket 1A, multiple first processed regions 14 are formed on the first surface 11. Specifically, two linear first processed regions 14 extend parallel to the longitudinal axis x on the first surface 11. As described above, the first processed regions 14 have different irregularities from the irregularities of the second processed regions 15 on the second surface 12. In this example, the circumferential width of the two linear first processed regions 14 around the longitudinal axis x is set to be constant. Other components similar to those of the previously described gasket 1 are designated by the same reference numerals, and redundant description will be omitted here. This gasket 1A can also achieve the same effects as those described above.

[0026] In manufacturing such a gasket 1A, concaves and convexes different from the concaves and convexes of the first surface 11 other than the first processing regions 14 are formed on the inner surface 22a of the upper mold 22 of the mold 20, corresponding to the positions of the two linear first processing regions 14. For example, the surface roughness of the concaves and convexes of the first surface 11 other than the first processing regions 14 may be set to be the same as the surface roughness of the concaves and convexes of the second processing regions 15 of the second surface 12. The linear first processing regions 14 may be formed around the entire circumference of the gasket body 10, or portions having a predetermined length may be arranged at predetermined intervals along the longitudinal axis x of the gasket body 10. The number of linear first processing regions 14 arranged in the circumferential direction may be one, or may be three or more.

[0027] Although the present invention has been described above through the above embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0028] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. Furthermore, the above-described embodiments do not limit the scope of application of the present invention, but may include any object to which the present invention can be applied. The components of the above-described embodiments, as well as their arrangement, materials, conditions, shape, size, etc., are not limited to those exemplified and can be modified as appropriate. For example, the present invention includes differences that arise during implementation due to manufacturing tolerances, etc. Furthermore, components shown in different embodiments can be partially substituted or combined with each other to the extent that they are not technically inconsistent. Furthermore, the various configurations can be selectively combined as appropriate to achieve at least some of the above-described problems and effects. [Explanation of symbols]

[0029] 1, 1A gasket, 10 gasket body, 11 first surface, 12 second surface, 13 boundary line, 14 first processing area (processing area), 15 second processing area, 20 mold, 21 lower mold, 21a inner surface, 22 upper mold, 23 space, 24, 25 parting surface, 26, 27 parting line, 28 elastic material, P1, P2 imaginary plane, x longitudinal axis

Claims

1. a gasket body formed from an elastic material and extending along a longitudinal axis; The gasket body has a first surface defined on one side with respect to the longitudinal axis and a second surface defined on the other side opposite to the one side with respect to the longitudinal axis, The first surface has a textured area with a texture different from the texture of the second surface.

2. The gasket of claim 1 , wherein the textured region has a surface roughness that is different from a surface roughness of the second surface.

3. The gasket of claim 1 , wherein the processed area is formed over the entire first surface.

4. The gasket of claim 1 , wherein the modified region extends at least partially linearly along the longitudinal axis.

5. the first surface is a surface of the gasket body on the one side of an imaginary plane including the longitudinal axis, The gasket according to any one of claims 1 to 4, wherein the second surface is a surface of the gasket on the other side of the imaginary plane.

6. The gasket according to claim 1 , wherein the processed region is formed by transferring irregularities formed on the inner surface of a mold.

7. 7. The gasket of claim 6, wherein a boundary line between the first surface and the second surface coincides with a parting line of the mold.

8. The gasket of claim 1 incorporated into a water electrolysis device or a fuel cell.

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