JP4706818B2 - Gasket for fuel cell - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gasket which is a kind of sealing device, and more particularly to a gasket suitable for being used as a gasket for a fuel cell.
[0002]
[Prior art]
For example, there are various types of gaskets used in fuel cells. Among them, gaskets integrated with separators are promising because they facilitate stack assembly and reduce costs. Is being viewed.
[0003]
As shown in FIG. 9 , in order to integrate the gasket 52 with the separator 51, a method is adopted in which the gasket 52 made of a rubber-like elastic body or the like is integrally formed in a mounting groove 53 provided in the separator 51.
[0004]
However, if the gasket 52 is simply integrally formed in the mounting groove 53 of the separator 51, the gasket 52 may fall out of the mounting groove 53 at the time of releasing immediately after molding or assembling the stack.
[0005]
On the other hand, in order to prevent the gasket 52 from falling off, there is a method in which an adhesive is applied in advance to the mounting groove 53 of the separator 51 before molding and then fixed.
[0006]
However, the use of an adhesive has the disadvantage of increasing the number of manufacturing steps and the cost burden, and if the adhesive is used to completely fix the gasket 52, the amount of adhesive applied increases. The increased elution of impurities from the adhesive may be a problem.
[0007]
Therefore, as shown in FIG. 10 , a method of preventing the gasket 52 from falling off by providing a through hole 54 that penetrates to the opposite surface 51 b of the separator 51 at the bottom of the mounting groove 53 of the separator 51 is considered ( For example, see Patent Document 1 or 2.)
[0008]
However, the prevention of the gasket 52 from falling off by the formation of the through hole 54 is effective when the gasket 52 is simultaneously formed on the front and back surfaces 51a and 51b of the separator 51 as shown in FIG. As shown in FIG. 5B, the following inconvenience also exists particularly in the type in which the gasket 52 is provided only on one side 51a of the separator 51.
[0009]
(1) After molding of the gasket 52, sink marks may occur in the gasket 52 in the through hole 54, and this may cause a decrease in sealing performance.
(2) If a problem occurs in the adhesion between the gasket 52 and the separator 51, a gas leak may occur between the separator front and back surfaces 51 a and 51 b through the through hole 54.
(3) The processing of the separator 51 becomes complicated. Moreover, since the thickness of the groove part of the separator 51 becomes thin, this part may be damaged.
(4) In the one-side gasket type of FIG. 10B, the sealing portion 55 of the through hole 54 exists on the opposite side of the gasket 52. For this reason, when this surface 51b is sealed by a separate gasket, the different hole material surfaces of the through hole sealing portion 55 and the separator 51 are simultaneously sealed, which may cause a leak.
[0010]
[Patent Document 1]
JP 2001-185174 A [Patent Document 2]
Japanese Patent Laid-Open No. 2002-0500369
[Problems to be solved by the invention]
In view of the above, the present invention has an object to provide a gasket in which a gasket can be attached to a separator relatively firmly without using an adhesive, and inconvenience due to formation of a through hole does not occur. To do.
[0012]
[Means for Solving the Problems]
To achieve the above object, a fuel cell gasket according to claim 1 of the present invention is a fuel that is attached to one separator of a pair of fuel cell separators that are two members facing each other and is in close contact with the other separator. A gasket for a fuel cell, wherein the gasket for a fuel cell integrally includes a mounting portion attached to a mounting groove provided in the one separator and a seal portion that is in close contact with the other separator. Is formed integrally with the one separator without coating, and a non-penetrating contact area expanding portion for increasing the contact area between the gasket and the one separator is provided at the groove bottom of the mounting groove, The gasket is provided with a portion to be filled and arranged in the contact area expanding portion, and the contact area expanding portion is Many along the serial mounting groove is formed by the holes of the non-penetrating shape arranged, and the contact area enlargement part is characterized in that it is arranged at a position displaced on a plane from the seal portion .
[0013]
Like the gasket of the present invention having the above-described configuration, a contact area expanding portion for increasing the contact area between the gasket and one separator is provided at the bottom of the mounting groove in one separator, and the contact area is expanded in the gasket. When the filling portion to be filled and arranged in the portion is provided, one separator and the gasket are newly brought into contact with each other at the contact area expanding portion and the filling portion. Therefore, it is possible to increase the contact area between the gasket and one separator as compared with the case where only one mounting groove is formed in one separator as shown in FIG. It becomes possible to increase the bonding force.
[0014]
Further, the contact area enlarged portion newly provided in one separator is formed as a non-penetrating shape that does not penetrate through the opposite surface of one separator, and therefore occurs when a through hole is formed as shown in FIG. It is possible to prevent various inconveniences from occurring.
[0015]
The contact area enlarged portion is formed as a hole-shaped recess and is disposed at a position shifted on the plane from the seal portion .
[0016]
The present invention includes the following embodiments.
[0017]
(A) A separator integrated seal, wherein a plurality of holes that do not penetrate deeper than the bottom surface of the groove for preventing the gasket from dropping off are provided in the separator groove.
[0018]
(B) The separator groove for molding the gasket is provided with a hole that is deeper than the bottom surface of the groove and does not penetrate to the opposite surface, thereby increasing the contact area between the separator and the gasket.
[0019]
(C) When providing holes in (B) above, a number of holes are arranged along the separator grooves. The shape of the hole may be any shape such as a circular hole, a long hole, an elliptical hole, or a polygonal hole.
[0020]
(D) The gasket of the present invention has a more effective structure when the gasket is integrally formed with the separator by injection molding or the like.
[0021]
(E) It is not particularly necessary to apply the adhesive which has been conventionally required to the groove surface of the separator, but in order to obtain more gasket adhesiveness, a smaller amount of adhesive than the conventional method is applied. Also good.
[0022]
(F) Moreover, in the Example shown below of this invention, although the gasket formation to the single side | surface of a separator is shown, the type which provides a gasket on the front and back both surfaces of a separator may be sufficient.
[0023]
(G) The gasket material is not particularly limited, but silicone rubber, fluororubber, EPDM, or the like is preferable.
[0024]
(H) According to the above items (A) to (G), the gasket can be firmly fixed without using an adhesive between the separator, and thus the construction period, man-hours, cost, etc. can be significantly reduced. it can. Moreover, adhesion and biting property can be increased by increasing the contact area between the gasket and the separator.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. First, reference examples will be described .
[0026]
FIG. 1 shows a cross section of a gasket 1 according to a reference example of the present invention. 2 is a partially cutaway perspective view of the gasket 1, and FIG. 3 is a sectional view of the gasket 1 after assembly (after stack assembly). The gasket 1 is used as a fuel cell gasket, and is configured as follows.
[0027]
That is, first, one separator 2 is provided as an attachment member (one separator in claim 1) to which the gasket 1 is attached, and the gasket 1 is attached to one surface 2a of the separator 2 by integral molding. In this case, the integral molding is performed by molding the gasket 1 by injection molding or the like with the separator 2 inserted in a rubber mold for molding the gasket 1, and the gasket 1 is bonded to the separator 2 at the same time as the molding. . However, no adhesive is applied in advance to the separator 2 side.
[0028]
The separator 2 is provided with a mounting groove 3 for mounting the gasket 1 on one surface 2a thereof. The mounting groove 3 is formed in a rectangular cross section and is formed long along the planar arrangement shape of the gasket 1. Has been. Further, a non-penetrating contact area expanding portion 4 for increasing the contact area between the separator 2 and the gasket 1 is provided at the groove bottom portion of the mounting groove 3. As shown in FIG. 2, it is formed by a plane circular hole in which a large number are arranged along the mounting groove 3. This hole-shaped contact area enlarged portion 4 does not penetrate through the opposite surface 2b of the separator 2, but is a tip when viewed from the one surface 2a side. The cross-sectional shape of the mounting groove 3 and the planar shape of the contact area enlarged portion 4 are not limited to the above.
[0029]
Further, the width (diameter of the hole) _{w 2} of the contact area enlargement section 4, the width being smaller than the dimension _{w 1 (w 2 <w 1} ) of the mounting groove 3, for example, 0.5mm or more in actual size The size is 5 mm or less, preferably 1 mm or more. Further, 5 mm depth _{d 2} from the separator one surface 2a of the contact area enlargement part 4 is larger than the depth _{d 1} of the mounting groove 3 _{(d 2> d} 1), for example, 1mm or more to scale Hereinafter, it is preferably formed in a size of 2 mm or more.
[0030]
The gasket 1 is formed of a predetermined rubber-like elastic body, and a mounting portion 5 filled in the mounting groove 3 of the separator 2 and a lip-shaped seal portion 6 integrally formed on the upper surface side of the mounting portion 5. Further, a portion to be filled (also referred to as an anchor portion) 7 filled and arranged in the contact area expanding portion 4 is integrally formed on the lower surface side of the attachment portion 5.
[0031]
The gasket 1 having the above configuration is integrally formed with the separator 2 as described above. The mounting groove 3 is provided on the one surface 2a of the separator 2 and the contact area including a large number of holes at the bottom of the mounting groove 3 is increased. Since the portion 4 is provided, when integrally molded, the attachment portion 5 comes into contact with the inner surface of the mounting groove 3 and is further pressed against the inner surface of the mounting groove 3 by molding pressure, and the filled portion 7 has a contact area. It contacts the inner surface of the enlarged portion 4 and is further pressed against the inner surface of the contact area enlarged portion 4 by molding pressure. Therefore, since it is possible to increase the contact area between the gasket 1 and the separator 2 as compared with the case where only the mounting groove 3 is formed in the separator 2, the bonding force between the gasket 1 and the separator 2 can be increased accordingly. It can be increased. Therefore, it is possible to provide the gasket 1 having a structure in which the gasket 1 is unlikely to fall off the mounting groove 3 of the separator 2 without using an adhesive.
[0032]
Further, since the contact area enlarged portion 4 is formed as a non-penetrating member that does not penetrate the opposite surface 2b of the separator 2, it is possible to prevent various inconveniences that occur when a through hole is formed. can do.
[0033]
Further, according to the gasket 1 having the above-described configuration, as shown in FIG. 3, the stack is assembled, and the gasket 1 is elastically formed between the separator 2 and the other separator (the other separator in claim 1) 8. When compressed, a pressing force in the direction of the arrow in the figure is generated (stress is applied so that the gasket 1 spreads in the contact area expanding portion 4), so that the portion to be filled 7 is the inner surface of the contact area expanding portion 4. Strongly pressed against (side). Therefore, since the so-called anchor effect for preventing detachment is exerted on the filled portion 7, it is possible to effectively prevent the gasket 1 from dropping from the mounting groove 3 of the separator 2.
[0034]
In the reference example described above, the contact area expanding portion 4 is a circular hole. However, for example, the following may be used.
[0035]
(A) A long hole, an elliptical hole, or a polygonal hole.
[0036]
(B) Instead of a hole, as shown in FIG. 4, a groove shape extending along the mounting groove 3 is used.
[0037]
(C) Regardless of whether it is a hole or a groove, as shown in FIG. 5, fine irregularities 9 are provided on the bottom surface portion of the contact area expanding portion 4, thereby expanding the anchor effect.
[0038]
(D) Regardless of whether it is a hole or a groove, as shown in FIG. 6, the width dimension of the bottom surface of the contact area enlarged portion 4 (the diameter dimension in the case of a circular hole) w ₃ is the width of the opening. It is formed wider than the dimension (in the case of a circular hole, its diameter dimension) w ₄ , thereby expanding the anchor effect.
[0039]
(E) Regardless of whether it is a hole or a groove, as shown in FIG. 7, the convex part 10 is provided in the center of the bottom face part of the contact area expansion part 4. When the convex portion 10 is provided in this manner, the pressing force to the inner surface (side surface) of the contact area expanding portion 4 when the gasket 1 described in FIG. 3 is compressed can be increased.
[0040]
Each of the contact area enlargement portions 4 shown in the above drawings is provided at a position directly below the seal portion 6, but in FIG. 8 according to the embodiment of the present invention, in addition to the configuration of the above reference example, in particular, contact The area expansion part 4 is arranged so as to be shifted from the seal part 6.
[0041]
【The invention's effect】
The present invention has the following effects.
[0042]
That is, in the fuel cell gasket of the present invention having the above-described configuration, a contact area expanding portion for increasing the contact area between the gasket and one separator is provided at the groove bottom of the mounting groove in one separator, and the gasket. In addition, since the filled portion to be filled and arranged in the contact area enlarged portion is provided, one separator and the gasket are newly brought into contact with each other in the contact area enlarged portion and the filled portion. The gasket is integrally formed with one separator without application of an adhesive. The contact area enlarged portion is formed by a hole in which a large number are arranged along the mounting groove. Therefore, since it is possible to increase the contact area between the gasket and one separator as compared with the case where only one mounting groove is formed in one separator, the bonding force between the gasket and one separator is increased accordingly. It can be increased. Therefore, it is possible to provide a gasket having a structure in which the gasket does not easily fall off from the mounting groove of one separator without using an adhesive.
[0043]
Further, since the contact area enlarged portion is formed as a non-penetrating shape that does not penetrate the opposite surface of one separator, various problems that occur when a through hole is formed can be prevented. be able to.
[Brief description of the drawings]
Figure 1 is a sectional view showing a state after a cross-sectional view of the gasket [2] view perspective of the notch portion of the gasket 3] with the same gasket set according to a reference example FIG. 4 to another reference example section of the gasket according to partially cut the perspective view FIG. 5 another cross-sectional view FIG. 7 another reference example of the gasket according to the sectional view Figure 6 another reference example of the gasket according to a reference example of the gasket according FIG . 8 is a sectional view of a gasket according to an embodiment of the present invention. FIG . 9 is a sectional view of a gasket according to a conventional example. FIG. 10 is a sectional view of a gasket according to another conventional example. [Explanation of symbols]
1 Gasket 2 Separator (one separator)
2a one surface 2b opposite surface 3 mounting groove 4 contact area enlarged portion 5 mounting portion 6 seal portion 7 filled portion 8 separator (the other separator)

Claims (1)

A fuel cell gasket (1) is attached to one separator (2) of a pair of fuel cell separators (2) (8), which are two members facing each other, and is in close contact with the other separator (8). Thus, a gasket for a fuel cell that integrally has an attachment portion (5) attached to a mounting groove (3) provided in the one separator (2) and a seal portion (6) in close contact with the other separator (8). In (1),
The fuel cell gasket (1) is integrally formed with the one separator (2) without application of an adhesive.
A non-penetrating contact area expanding portion (4) for increasing the contact area between the gasket (1) and the one separator (2) is provided at the groove bottom of the mounting groove (3), and the gasket (1) The portion to be filled (7) to be filled in the contact area enlarged portion (4) is provided,
The contact area enlarged portion (4) is formed by a non-through hole in which a large number are arranged along the mounting groove (3) ,
And the said contact area expansion part (4) is arrange | positioned in the position which shifted | deviated on the plane from the said seal part (6) , The gasket for fuel cells characterized by the above-mentioned.

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