Gasket having Compression Thickness Saving Structure

Abstract

According to one aspect of the present invention, a fuel cell gasket cross-sectional structure that reduces the gasket reaction force upon compression is provided, characterized by forming embossed bead portions in equal proportions on both sides of a pressure surface on one side of the gasket and forming recessed cushioning portions between the bead portions. Accordingly, the present invention can reduce the gasket volume and lower the gasket reaction force, thereby increasing the compression amount and surface pressure when compressed with the same load, and optimizing the gasket performance and fastening force.

Description

Technology Field

[0001] The present invention relates to a cross-sectional structure of a fuel cell gasket, and more specifically, to a cross-sectional structure of a fuel cell gasket with reduced gasket reaction force during compression, wherein the gasket reaction force after compression is reduced when a gasket cross-section having the same gasket height is compressed by the same load, thereby designing the compression amount and surface pressure to be high, and thus optimizing the compression amount of the gas diffusion layer and the stack fastening force. Background Technology

[0002] Generally, when looking at the configuration of a fuel cell stack based on a single unit cell, as shown in FIG. 1, a membrane-electrode assembly (MEA) is arranged at the innermost part, and this membrane-electrode assembly consists of a polymer electrolyte membrane (10) capable of moving hydrogen cations (protons), and catalyst layers coated on both sides of the electrolyte membrane to allow hydrogen and oxygen to react, namely an air electrode (12: cathode) and a fuel electrode (14: anode).

[0003] Additionally, a gas diffusion layer (GDL) (16) and a gasket (18) are stacked sequentially on the outer part where the air electrode (12) and the fuel electrode (14) are located, and a separator plate (20) with a flow field formed to supply fuel and discharge water generated by the reaction is stacked on the outside of the gas diffusion layer (16).

[0004] After stacking multiple such unit cells, an end plate (30) is attached to the outermost part to secure them, thereby forming a fuel cell stack.

[0005] Accordingly, at the fuel electrode (14) of the fuel cell stack, the oxidation reaction of hydrogen proceeds to generate hydrogen ions (protons) and electrons, and the hydrogen ions and electrons generated at this time move to the air electrode (12) through the electrolyte membrane (10) and the separator (20), respectively. At the air electrode (12), water is produced through an electrochemical reaction involving the hydrogen ions and electrons moved from the fuel electrode (14) and oxygen in the air, and at the same time, electrical energy is generated from the flow of electrons.

[0006] Among the components of the fuel cell stack described above, the separator (in particular, the metal separator) is required to have the following functions.

[0007] Since it serves as a passage to supply reducing gas and oxidizing gas to the cell within the fuel cell stack, a passage to supply cooling water to cool the stack, and a passage to move the generated current, airtightness or liquid tightness is required so that the reducing gas, oxidizing gas, and cooling water do not mix with each other. Accordingly, a rubber seal is applied to the surface of the separator to maintain airtightness of fluids and gases while also performing the role of maintaining load.

[0008] In addition, the gasket in the fuel cell stack is bonded to the separator plate and serves as a criterion for dividing each unit cell of the fuel cell stack, while simultaneously functioning to independently seal the hydrogen, cooling water, and air passages formed on the surface of the separator plate.

[0009] Such gaskets are generally manufactured with a rectangular cross-sectional shape, as shown in Fig. 5.

[0010] However, when such conventional gaskets are designed with a square cross-section, the volume of the gasket is large and the resulting reaction force is large, which leads to a problem where the gasket compression amount is low and the surface pressure drops proportionally to the reduced compression amount. Prior art literature

[0011] Republic of Korea Registered Patent No. 10-1173058 The problem to be solved

[0012] The present invention has been devised to solve the aforementioned problems, and its purpose is to provide a fuel cell gasket cross-sectional structure with reduced gasket reaction force during compression, which optimizes the compression amount of the gas diffusion layer and the stack fastening force by designing the compression amount and surface pressure to reduce the gasket reaction force after compression when a gasket cross-section having the same gasket height is compressed by the same load.

[0013] Another objective of the present invention is to provide a fuel cell gasket cross-sectional structure that reduces the gasket reaction force during compression by forming raised bead portions in equal proportions on both sides of a pressure surface on one side of the gasket and forming recessed buffer portions between the bead portions. means of solving the problem

[0014] According to one aspect of the present invention for achieving the above-mentioned purpose, a fuel cell gasket cross-sectional structure that reduces the gasket reaction force upon compression may be provided, characterized by forming embossed bead portions in equal proportions on both sides of a pressure surface on one side of the gasket and forming recessed cushioning portions between the bead portions.

[0015] Here, when the width of the buffer portion is denoted as W1 and the width of the bead portion as W2, it can be formed as W1 = 0.3 ~ 0.6 * W2.

[0016] And, when the height from the other side pressure surface of the gasket to the bottom of the buffer section is denoted as h1 and the maximum compression height of the bead section is denoted as h2, it can be formed such that h1 < h2.

[0017] In addition, the side of the above bead portion can be formed as an inclined surface.

[0018] And, the corner of the pressure surface of the bead portion can be formed into a round (112).

[0019] According to another aspect of the present invention, a fuel cell gasket cross-sectional structure that reduces gasket reaction force upon compression may be provided, characterized by forming first beads in a raised shape on both sides of a pressure surface on one side of the gasket in equal proportions, forming a cushioning portion in a recessed shape between the first beads, and forming a second bead protruding in a raised shape on the pressure surface of the first beads to increase surface pressure.

[0020] Here, when the width of the buffer portion is denoted as W1 and the width of the first bead as W2, W1 can be formed as W1 = 0.3 ~ 0.6 * W2.

[0021] And, when the height from the other side pressure surface of the gasket to the bottom of the buffer section is denoted as h1, the maximum compression height of the second bead is denoted as h2, and the height to the pressure surface of the first bead is denoted as h3, it can be formed such that h1 < h2 < h3.

[0022] And, the side of the first bead can be formed as an inclined surface.

[0023] And, the corners of the pressure surfaces of the first and second beads can be formed into rounds (112).

[0024] And, the height h1 to the bottom of the buffer section can be formed to be 0.

[0025] In addition, the above gasket can be used to bond to the separator of the fuel cell stack. Effects of the invention

[0026] As described above, the present invention has the effect of optimizing the compression amount of the gas diffusion layer and the stack fastening force by designing the compression amount and surface pressure to lower the gasket reaction force after compression and increase the compression amount when a gasket cross-section having the same gasket height is compressed with the same load. Brief explanation of the drawing

[0027] FIG. 1 is a schematic diagram illustrating the configuration of a fuel cell stack of the prior art. FIG. 2 is a cross-sectional view illustrating a fuel cell gasket cross-sectional structure with reduced gasket reaction force upon compression according to one embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating a fuel cell gasket cross-sectional structure with reduced gasket reaction force upon compression according to a second embodiment of the present invention. FIG. 4 is a cross-sectional view illustrating a fuel cell gasket cross-sectional structure with reduced gasket reaction force upon compression according to the 3rd embodiment of the present invention. FIGS. 5 and FIGS. 8 are graphs illustrating the surface pressure and compression amount when a gasket of the prior art and a gasket according to an embodiment of the present invention are compressed with the same load. Specific details for implementing the invention

[0028] Specific structural or functional descriptions of embodiments according to the concept of the present invention disclosed herein are provided merely for the purpose of explaining embodiments according to the concept of the present invention, and embodiments according to the concept of the present invention may be implemented in various forms and are not limited to the embodiments described herein.

[0029] Hereinafter, embodiments will be described in detail with reference to the attached drawings. However, the scope of the patent application is not limited or restricted by these embodiments. Identical reference numerals in each drawing indicate identical components.

[0030] Hereinafter, the present invention configured as described above will be explained in detail with reference to the attached drawings.

[0031] FIG. 2 is a cross-sectional view illustrating a fuel cell gasket cross-sectional structure with reduced gasket reaction force upon compression according to the first embodiment of the present invention, FIG. 3 is a cross-sectional view illustrating a fuel cell gasket cross-sectional structure with reduced gasket reaction force upon compression according to the second embodiment of the present invention, FIG. 4 is a cross-sectional view illustrating a fuel cell gasket cross-sectional structure with reduced gasket reaction force upon compression according to the third embodiment of the present invention, and FIG. 5 and FIG. 8 are graphs illustrating the surface pressure and compression amount when a gasket of the prior art and a gasket according to an embodiment of the present invention are compressed with the same load.

[0032] FIG. 2 is a cross-sectional view illustrating a fuel cell gasket cross-sectional structure that reduces the gasket reaction force upon compression according to one embodiment of the present invention. Referring to FIG. 2, one embodiment of the present invention may provide a gasket (100) having a cross-sectional structure in which raised bead portions (110) are formed in equal proportions on both sides of one side of the pressure surface of the gasket (100), and a recessed cushioning portion (120) is formed between the bead portions (110).

[0033] At this time, the gasket (100) of the present invention can be used to bond to the separator plate of the fuel cell stack.

[0034] Such a gasket (100) is bonded to the separator plate of the fuel cell stack to separate each unit cell of the fuel cell stack, while also functioning to independently seal the hydrogen, cooling water, and air passages formed on the surface of the separator plate.

[0035] The above gasket (100) can be manufactured by injection molding using a mold, and can be manufactured using a rubber material, and in particular, a fluororubber or polymer resin system can be used.

[0036] In addition, the gasket (100) manufactured according to the first embodiment of the present invention can be used by symmetrically combining a pair of them on both sides based on the separator plate.

[0037] At this time, a bead portion (110) and a buffer portion (120) according to the present invention can be formed on the outer surface of each of the symmetrical gaskets (100).

[0038] At this time, when the width of the buffer portion (120) is denoted as W1 and the width of the bead portion (110) is denoted as W2, it is preferable to form W1 = 0.3 ~ 0.6 * W2.

[0039] In other words, the cushioning portion (120) of the present invention is designed so that its width (W1) is at least 30% of the width (W2) of the bead portion (110). When the width (W1) of the cushioning portion (120) is sufficiently secured, it is possible to prevent the bead portion (110) from coming into contact with each other or coming into contact with the cushioning portion (120) even when the gasket (100) is compressed and deformed as shown in FIG. 6.

[0040] FIGS. 6 and 7 are graphs showing the cross-sectional change of a gasket when a constant external pressure is applied to a gasket (100) manufactured according to one embodiment of the present invention.

[0041] Referring to FIG. 6, it can be seen that the compressive deformation stress due to the load is mainly concentrated on the bottom surface and both sides of the buffer (120), that is, on the buffer (120).

[0042] At this time, due to the applied stress, it can be seen that the bottom surface of the buffer part (120) and the inclined surfaces (111) on both sides of the bead part (110) are curved and bulge inward toward the receiving space.

[0043] And, when the height from the other side pressure surface of the gasket (100) to the bottom of the buffer part (120) is denoted as h1 and the maximum compression height of the bead part (110) is denoted as h2, it can be formed such that h1 < h2.

[0044] When formed in this way, it is possible to prevent the bottom of the buffer part (120) from coming into contact with the opposite gasket and separator plate and interfering when the gasket (100) is compressed.

[0045] That is, in the present invention, the depth of the buffer portion (120) can be adjusted so that the bottom surface of the buffer portion (120) is positioned at a lower position than the maximum compression height (h2) of the bead portion (110).

[0046] Additionally, the side of the bead portion (110) can be formed as an inclined surface (111). Forming the side of the bead portion (110) as an inclined surface (111) is intended to allow the gasket (100) to be easily ejected from the mold after molding during the injection molding process of the gasket (100) using a mold.

[0047] Meanwhile, by adopting the inclined surface (111) structure as described above, a stable support structure such as a pyramid structure is obtained. This allows the pressure applied to the gasket (100) to be evenly distributed toward the separator plate, thereby increasing the adhesion force of the gasket (100) and stabilizing the joint position of the gasket to improve sealing efficiency.

[0048] In addition, the corner of the pressure surface of the bead portion (110) can be formed into a round (112).

[0049] By forming such a round (112), it prevents stress from concentrating on the corners of the pressure surface of the bead portion (110) and acts to distribute the stress.

[0050] As shown in FIG. 7, the surface pressure of the gasket according to the first embodiment of the present invention was measured to be 1.10 MPa, and it can be seen that the surface pressure is significantly improved compared to the surface pressure of 0.85 MPa of the conventional square cross-section gasket shown in FIG. 5.

[0051] In addition, referring to the graphs in FIGS. 5 and FIGS. 7, when a gasket with a thickness of 0.45 mm before compression was compressed, the height after compression was measured to be 0.41 mm and 0.39 mm, respectively. This indicates that the gasket according to the first embodiment of the present invention has increased compression amount along with increased surface pressure compared to a conventional gasket.

[0052] FIG. 3 is a cross-sectional view illustrating a fuel cell gasket cross-sectional structure that reduces the gasket reaction force upon compression according to a second embodiment of the present invention. Referring to FIG. 3, the second embodiment of the present invention may provide a gasket (100) with a cross-sectional structure that increases surface pressure by forming first beads (110a) in a raised shape on both sides of a pressure surface of one side of the gasket (100) in equal proportions, forming a cushioning part (120) in a recessed shape between the first beads (110a), and forming a second bead (110b) that protrudes in a raised shape on the pressure surface of the first beads (110a).

[0053] At this time, the gasket (100) of the present invention can be used to bond to the separator plate of the fuel cell stack.

[0054] Such a gasket (100) is bonded to the separator plate of the fuel cell stack to separate each unit cell of the fuel cell stack, while also functioning to independently seal the hydrogen, cooling water, and air passages formed on the surface of the separator plate.

[0055] The above gasket (100) can be manufactured by injection molding using a mold, and can be manufactured using a rubber material, and in particular, a fluororubber or polymer resin system can be used.

[0056] In addition, the gasket (100) manufactured according to the second embodiment of the present invention can be used by symmetrically combining a pair of them on both sides based on the separator plate.

[0057] At this time, a bead portion (110) according to the present invention, namely a first bead (110a), a second bead (110b), and a buffer portion (120), can be formed on the outer surface of each of the symmetrical gaskets (100).

[0058] At this time, when the width of the buffer portion (120) is denoted as W1 and the width of the first bead (110a) is denoted as W2, it is preferable to form W1 = 0.3 ~ 0.6 * W2.

[0059] In other words, the cushioning member (120) of the present invention is designed so that its width (W1) is at least 30% of the width (W2) of the first bead (110a). When the width (W1) of the cushioning member (120) is sufficiently secured, it is possible to prevent the first bead (110a) from coming into contact with each other or coming into contact with the cushioning member (120) even when the gasket (100) is compressed and deformed as shown in FIG. 6.

[0060] FIG. 8 is a graph showing the cross-sectional change of a gasket when a constant external pressure is applied to a gasket (100) manufactured according to the second embodiment of the present invention.

[0061] Referring to FIG. 8, it can be seen that the compressive deformation stress due to the load is mainly concentrated on the bottom surface and both sides of the buffer (120), that is, on the buffer (120).

[0062] At this time, due to the applied stress, it can be seen that the bottom surface of the buffer (120) and the inclined surfaces (111) on both sides of the first bead (110a) are curved and bulge inward toward the receiving space.

[0063] And, when the height from the other side pressure surface of the gasket to the bottom of the buffer part (120) is denoted as h1, the maximum compression height of the second bead (110b) is denoted as h2, and the height to the pressure surface of the first bead (110a) is denoted as h3, it can be formed such that h1 < h2 < h3.

[0064] When formed in this way, it is possible to prevent the bottom of the buffer part (120) from coming into contact with the opposite gasket and separator plate and interfering when the gasket (100) is compressed.

[0065] That is, in the present invention, the depth of the buffer portion (120) can be adjusted so that the bottom surface of the buffer portion (120) is positioned at a lower position than the maximum compression height (h2) of the first bead (110a).

[0066] Additionally, the side of the first bead (110a) can be formed as an inclined surface (111). Forming the side of the first bead (110a) as an inclined surface (111) is intended to allow the gasket (100) to be easily ejected from the mold after molding during the injection molding process of the gasket (100) using a mold.

[0067] Meanwhile, by adopting the inclined surface (111) structure as described above, a stable support structure such as a pyramid structure is obtained. This allows the pressure applied to the gasket (100) to be evenly distributed toward the separator plate, thereby increasing the adhesion force of the gasket (100) and stabilizing the joint position of the gasket to improve sealing efficiency.

[0068] In addition, the corners of the pressure surfaces of the first bead (110a) and the second bead (110b) can be formed into rounds (112).

[0069] By forming such a round (112), it is possible to prevent stress from concentrating on the corners of the pressure surfaces of the first bead (110a) and the second bead (110b) and to distribute the stress.

[0070] As shown in Fig. 8, the surface pressure of the gasket according to the second embodiment of the present invention was measured to be 2.16 MPa, and it can be seen that the surface pressure has been significantly improved compared to the surface pressure of 0.85 MPa of the conventional square cross-section gasket.

[0071] In addition, through the graph, it can be seen that the height after compression is lower than that of the conventional square cross-section gasket and the gasket according to the first embodiment of the present invention, which indicates that the amount of compression has increased along with the increase in surface pressure.

[0072] FIG. 4 is a cross-sectional view illustrating a fuel cell gasket cross-sectional structure with reduced gasket reaction force upon compression according to the third embodiment of the present invention. Referring to FIG. 4, the height (h1) to the bottom of the buffer section (120) can be formed to be 0.

[0073] For example, in the present invention, the compression amount and surface pressure of the gasket can be further increased by adjusting the depth of the buffer section (120). As the depth of the buffer section (120) is formed deeper, the compression amount and surface pressure of the gasket increase. If necessary, the depth of the buffer section (120) can be formed to the maximum by making the height (h1) to the bottom of the buffer section (120) zero, as shown in FIG. 4, thereby maximizing the compression amount and surface pressure of the gasket.

[0074] Although the third embodiment of the present invention illustrates a multi-stage structure of the first bead (110a) and the second bead (110b) through FIG. 4, it is not limited thereto, and an embodiment may be provided in which a single bead shape as seen in FIG. 2 or another buffer part is formed in each bead part.

[0075] As described above, the present invention forms raised bead portions in equal proportions on both sides of a pressure surface on one side of a gasket and forms recessed cushioning portions between the bead portions, thereby reducing the gasket volume and lowering the gasket reaction force, so that when compressed with the same load, the compression amount and surface pressure increase, and the gasket performance and fastening force can be optimized.

[0076] In addition, considering that the gasket according to the embodiment of the present invention generally performs well when the gas diffusion layer is compressed to about 30%, the gasket is designed so that when the gasket is compressed with the same load, the surface pressure is maximized and the height of the gas diffusion layer after compression is compressed to about 30%, thereby providing a very excellent effect of the fastening force of the fuel cell stack.

[0077] As described above, the present invention is not limited to the specific preferred embodiments described above, and any person skilled in the art to which the invention pertains can make various modifications without departing from the essence of the invention as claimed in the claims, and such modifications will be within the scope of the claims. Explanation of the symbols

[0078] 100: Gasket 110: Beads 110a: 1st bead 110b: 2nd bead 111: Slope 112: Round 120: Buffer

Claims

Claim 1 A fuel cell gasket cross-sectional structure that reduces gasket reaction force upon compression, characterized by forming embossed bead portions in equal proportions on both sides of a pressure surface on one side of the gasket, forming a recessed buffer portion between the bead portions, forming the sides of the bead portions as inclined surfaces, and forming the corners of the pressure surface of the bead portions as rounded surfaces, wherein the gasket is bonded to a separator plate of a fuel cell stack, and wherein the pressure applied to the gasket is evenly distributed toward the separator plate side by the bead portions having an inclined surface structure, thereby increasing the adhesion force of the gasket and stabilizing the bonding position of the gasket to improve sealing efficiency. Claim 2 A fuel cell gasket cross-sectional structure that reduces gasket reaction force upon compression, characterized in that, in claim 1, when the width of the buffer portion is denoted as W1 and the width of the bead portion is denoted as W2, W1 is formed as W2 = 0.3 ~ 0.6 * W2. Claim 3 A fuel cell gasket cross-sectional structure that reduces gasket reaction force during compression, characterized in that, in claim 1, when the height from the other side pressure surface of the gasket to the bottom of the buffer section is denoted as h1 and the maximum compression height of the bead section is denoted as h2, h1 < h2. Claim 4 delete Claim 5 delete Claim 6 A fuel cell gasket cross-sectional structure that reduces gasket reaction force upon compression, characterized by forming first beads in a raised shape on both sides of a pressure surface on one side of the gasket in equal proportions, forming a cushioning portion in a recessed shape between the first beads, and forming a second bead protruding in a raised shape on the pressure surface of the first bead to increase surface pressure, forming the side of the first bead as an inclined surface, and forming the corners of the pressure surfaces of the first bead and the second bead as rounds, wherein the gasket is bonded to a separator plate of a fuel cell stack, and the pressure applied to the gasket is evenly distributed toward the separator plate side by the first bead having an inclined surface structure, thereby increasing the adhesion force of the gasket and stabilizing the bonding position of the gasket to improve sealing efficiency. Claim 7 A fuel cell gasket cross-sectional structure that reduces gasket reaction force during compression, characterized in that, in claim 6, when the width of the buffer portion is denoted as W1 and the width of the first bead is denoted as W2, W1 is formed as W2 = 0.3 ~ 0.6 * W2. Claim 8 A fuel cell gasket cross-sectional structure that reduces gasket reaction force during compression, characterized in that, in claim 6, the height from the other side pressure surface of the gasket to the bottom of the buffer section is denoted as h1, the maximum compression height of the second bead is denoted as h2, and the height to the pressure surface of the first bead is denoted as h3, wherein h1 < h2 < h3. Claim 9 delete Claim 10 delete Claim 11 A fuel cell gasket cross-sectional structure that reduces gasket reaction force upon compression, characterized in that, in claim 3 or 8, the height (h1) to the bottom of the buffer section is formed to be 0. Claim 12 delete

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