JP2004047495A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid polymer electrolyte film type fuel cell which absorbs a stretch and contraction in a direction of a separator lamination. <P>SOLUTION: In the solid polymer electrolyte film type fuel cell composed of a pair of electrodes formed at both sides of the solid polymer electrolyte film with their outside held by a pair of separators made of a thin metal plate, an insulation member 201 is arranged at the peripheral part of a communication hole formed on the separator, for example, at the peripheral part of an exhaust port side fuel gas communication hole 42b. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a solid polymer electrolyte membrane fuel cell and a fuel cell stack in which a plurality of the fuel cells are stacked, and more particularly to a technique effective for absorbing expansion and contraction in the direction of stacking separators.

2. Description of the Related Art As a fuel cell, there is a solid polymer electrolyte membrane fuel cell in which a pair of electrodes is provided on both sides of a solid polymer electrolyte membrane, and the outside is sandwiched between a pair of separators.
In this fuel cell, a flow path for a fuel gas (for example, hydrogen) is provided on one surface of a separator arranged to face one electrode, and an oxidant gas (for example, oxygen) is formed on one surface of a separator arranged to face the other electrode. Is provided, and a cooling medium flow path is provided on a surface opposite to a surface facing one of the electrodes.

When a fuel gas is supplied to one electrode reaction surface, hydrogen is ionized here and moves to the other electrode via the solid polymer electrolyte membrane. The electrons generated during this time are taken out to an external circuit and used as DC electric energy.
Since the oxidizing gas is supplied to the other electrode, hydrogen ions, electrons, and oxygen react to generate water.
The surface of the separator opposite to the electrode reaction surface is cooled by a cooling medium flowing between the separators.

Since the reaction gas and the cooling medium need to be passed through independent flow paths, a sealing technique for partitioning between the flow paths is important.
As a seal portion, a pair of solid polymer electrolyte membranes and a pair of solid polymer electrolyte membranes provided on both sides thereof are provided around a communication hole formed through the separator to distribute and supply the reaction gas and the cooling medium to each fuel cell of the fuel cell stack. There are an outer periphery of an electrode membrane structure composed of an electrode, an outer periphery of a coolant flow path surface of a separator, an outer periphery of front and back surfaces of a separator, and the like. As a sealing material, a soft and moderately resilient material such as organic rubber is used. Adopted.

By the way, when a fuel cell stack is configured by stacking a plurality of fuel cells, and the fuel cell stack is mounted on a vehicle, depending on the installation position, water droplets or the like may be scattered and the fuel cell may be flooded, or between the separators. Dust may enter the gap.
However, it is possible to prevent the water and dust from entering the reaction gas flow path and the cooling medium flow path by the seal material.

However, when stacking the separators, the thickness of the electrode film structure varies, the separator (particularly, a thin metal separator) is warped or distorted, and the compressive load received from both ends of the fuel cell stack is not sufficient. If it is uniform, the separators will not be stacked in parallel, causing inclination and torsion, so that the amount of compression of each sealing material will be unbalanced, and the sealing performance of the sealing material having a small amount of compression will be deteriorated.
In addition, when stacking the separators, it is also difficult to accurately stack the separators without shifting the relative position along the electrode reaction surface.

As a countermeasure, for example, a method of providing a frame-shaped member made of resin at the outer edge of the separator to prevent foreign matter from entering the gaps between the separators and allowing the separators to be stacked in parallel is considered (for example, See Patent Literature 1, Patent Literature 2, and Patent Literature 3).
JP-A-10-074530 JP 07-249417 A JP-A-61-279069

However, when the sealing material or the electrode membrane structure shrinks in the separator laminating direction due to aging, or when the fuel cell expands and contracts due to heat or the like, the following problems occur.
For example, if the height of the sealing material projecting from the separator is lower than the height of the frame-shaped member, shrinkage of the separator interval is regulated by the frame-shaped member, so that a gap is formed between the separator and the sealing material or the electrode film structure. May occur, resulting in a decrease in power generation performance and a power failure.

On the other hand, when the separator interval is widened due to heat or the like, the sealing material made of rubber or the like elastically returns in the separator laminating direction and expands. However, the frame-shaped member made of resin or the like does not extend in the separator laminating direction, and cannot follow the expansion of the separator interval. For this reason, a gap is generated between the frame-shaped members, and there is a possibility that foreign matter may enter therethrough.

Furthermore, it is necessary to prevent a liquid junction through which a current flows through the cooling medium in the cooling medium flow path, and to prevent an electrical short circuit between adjacent separators in the reaction gas flow path.
In particular, in the case of a fuel cell using a thin metal separator, the distance between the separators is short. Therefore, considering the possibility that foreign substances such as dust and carbon particles are mixed in the reaction gas, the electric power between adjacent separators is reduced. It is desirable to take special measures to prevent temporary short circuits.

The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to absorb expansion and contraction in a separator stacking direction in a solid polymer electrolyte membrane type fuel cell and a fuel cell stack. The purpose is to facilitate positioning during lamination and to insulate the periphery of the communication hole formed in the separator.

In order to achieve the above object, the fuel cell according to claim 1, wherein a pair of electrodes is provided on both sides of the solid polymer electrolyte membrane, and the outside thereof is sandwiched between a pair of thin metal plate separators. In the fuel cell, the communication holes formed in the separator (for example, the inlet-side oxidant gas communication hole 41a, the outlet-side oxidant gas communication hole 41b, the inlet-side fuel gas communication hole 42a, and the outlet-side fuel gas communication in the embodiment) Insulating members (for example, the insulating members 201, 211, 221, 231, 231 and 241, 271 in the embodiment) are provided around the holes 42b, the inlet-side cooling medium communication holes 43a, and the outlet-side cooling medium communication holes 43b). It is characterized by having.

According to this configuration, it is possible to prevent a liquid junction in the cooling medium flow path and an electrical short circuit between the adjacent separators in the reaction gas flow path.

According to a second aspect of the present invention, in the fuel cell according to the first aspect, each insulating member of the adjacent separator (for example, the insulating member 201 in the embodiment) is provided with a gap (for example, , The gap 203 according to the embodiment.

According to this configuration, the expansion and contraction of the separator interval can be absorbed by increasing and decreasing the gap in the stacking direction of the separators.

Further, a fuel cell or a fuel cell stack having the following configuration can be employed.
In the fuel cell of the first configuration, a pair of electrodes (for example, the electrode 9 in the embodiment) is provided on both sides of a solid polymer electrolyte membrane (for example, the solid polymer electrolyte membrane 7 in the embodiment), and the outside thereof is provided. In a fuel cell (for example, the fuel cell 1 in the embodiment) sandwiched between a pair of separators (for example, the separator 3 in the embodiment), expansion and contraction of the separator interval is performed at an outer edge of the separator while sealing a gap between the separators. The present invention is characterized in that an insulating frame-shaped member (for example, the frame-shaped member 61, 81, 91, 101, 111, 121, 131, 141, 251, 261 in the embodiment) is provided.
According to this configuration, a gap between the separator and the frame-shaped member is not generated for the movement in which the separator interval is widened, and the movement is not for the movement in which the separator interval is narrowed. It is no longer blocked by the picture frame.
Therefore, no gap is created between the separator and the frame-shaped member when the separator interval is widened, and the movement is prevented by the frame-shaped member when the separator interval is narrowed. As a result, it is possible to effectively prevent foreign matters from entering when the separator interval is increased and sealing failure due to aging of the sealing material or the like, and maintain good power generation performance.

The fuel cell of the second configuration is different from the fuel cell of the first configuration in that the frame members (for example, the frame members 101, 111, 121, and 131 in the embodiment) are configured to be relatively slidable. It is characterized by having.
According to this configuration, the width of the separator interval is relatively absorbed by the frame members sliding relative to each other.
Therefore, the gap between the separators can be mechanically absorbed by relative sliding between the frame-shaped members. As described above, foreign matter intrusion at the time when the separator interval is increased, and poor sealing due to deterioration with time of the sealing material or the like can be prevented. It can be effectively prevented and good power generation performance can be maintained.

The fuel cell according to the third configuration is the fuel cell according to the first or second configuration, wherein the separator is made of metal, and the frame-shaped member (for example, the frame-shaped member 61, 81, 91, 261) is composed of a hard material (for example, the main body portions 61a, 81a, 91a, 261a in the embodiment) and a soft material (for example, the expansion-contraction absorbing portions 61b, 81b, 91b, 261b in the embodiment). It is characterized by having.
According to this configuration, since the soft member can elastically contract in the separator laminating direction, the relative approach of the separator is not restricted.
Further, with respect to the expansion of the separator interval, the soft member elastically returns in the separator laminating direction and expands to follow the separator.
Therefore, since the soft member is elastically contractible in the separator laminating direction, it does not restrict the relative approach of the separator. Since it follows the separator, similarly to the above, it is possible to effectively prevent foreign matter from entering when the separator interval is increased, and sealing failure due to aging deterioration of the sealing material or the like, and maintain good power generation performance.

A fuel cell according to a fourth configuration is the fuel cell according to the first configuration, wherein the frame-shaped member is formed by a separator positioning means (for example, a combination of the concave portion 123 and the convex portion 125 in the embodiment, and the end surfaces 131A and 131B). , And a combination of a triangular groove 143 and a triangular ridge 145).
According to this configuration, it is possible to prevent relative displacement between the separators that may occur when the separators are stacked.
Therefore, the alignment of the separator is automatically performed at the time of laminating the separator, so that workability at the time of assembly and maintenance is improved.

A fuel cell according to a fifth configuration is the fuel cell according to any one of the first to fourth configurations, wherein an outer peripheral end surface of the separator is formed of the frame-shaped member (for example, the frame-shaped members 61, 81, 91, and 91 in the embodiments). 101, 111, 121, 131, 141, 251, 261).
According to this configuration, it is possible to prevent an electrical short circuit on the outer peripheral end face between the adjacent separators.
Therefore, it is possible to effectively prevent an electrical short circuit on the outer peripheral end face between the adjacent separators, and it is possible to maintain good power generation performance.

A fuel cell according to a sixth configuration is the fuel cell according to any one of the first to fifth configurations, in which a reaction surface outer periphery sealing member (for example, an outer periphery sealing material 52 in the embodiment) is provided to surround the reaction surface of the separator. The outer peripheral portion of the reaction surface outer peripheral sealing member is entirely covered with an insulating outer edge member (for example, the expansion and contraction absorbing portion 261b in the embodiment).
According to this configuration, since the metal exposed portion of the separator in the outer portion of the reaction surface outer peripheral seal member is entirely covered with the insulating outer edge member, the corrosion resistance is improved, and an electrical short circuit between adjacent separators is prevented. Can be prevented.
Therefore, it is possible to improve the corrosion resistance of the separator, effectively prevent an electrical short circuit between adjacent separators, and maintain good power generation performance.

The fuel cell according to the seventh configuration is the same as the fuel cell according to the sixth configuration, except that both surfaces of the outer peripheral portion of the reaction surface outer peripheral sealing member (for example, the outer peripheral sealing member 52 in the embodiment) are formed over the entire surface. It is characterized in that it is covered with an insulating outer edge member (for example, the expansion and contraction absorbing portion 261b in the embodiment) integrally formed with the seal member.
According to this configuration, since the metal exposed portion of the separator in the outer portion of the reaction surface outer peripheral seal member is entirely covered with the insulating outer edge member on both surfaces, the corrosion resistance is further improved, and the electrical resistance between the adjacent separators is improved. A short circuit can be further prevented.
Therefore, the corrosion resistance of the separator can be further improved, and an electrical short circuit between the adjacent separators can be more effectively prevented, so that good power generation performance can be maintained. Further, since the reaction surface outer peripheral seal member and the insulating outer edge member can be molded at the same time, production cost can be reduced.

The fuel cell according to the eighth configuration is the fuel cell according to the sixth or seventh configuration, wherein one of the reaction surface outer peripheral sealing members (for example, the outer peripheral sealing material flat portion 52b in the embodiment) is adjacent to the separator. The reaction surface outer peripheral sealing member of the other separator (for example, the outer peripheral sealing material convex portion 52a in the embodiment) which has a flat shape and is opposed thereto has a convex shape.
According to this configuration, one of the combinations of the reaction surface outer peripheral seal members is set to a flat shape and the other is set to a convex shape, so that the convex reaction surface outer periphery corresponding to the flat shape reaction surface outer peripheral seal member is combined. The displacement of the relative position of the seal member can be absorbed.
Therefore, the relative position shift of the convex-shaped reaction surface outer peripheral seal member corresponding to the flat-shaped reaction surface outer peripheral seal member can be absorbed, so that productivity is improved.

In a ninth configuration, in the fuel cell stack configured by stacking a plurality of the fuel cells having any one of the first to eighth configurations, the frame-shaped member seals a gap between the separators and forms a gap between the separators. It is characterized by allowing expansion and contraction.
According to this configuration, not only within a single fuel cell but also between adjacent fuel cells, a gap is created between the separator and the frame member for the movement of increasing the separator interval. In addition, when the movement of the separator is reduced, the movement is not prevented by the frame-shaped member.
Therefore, not only within a single fuel cell but also between adjacent fuel cells, the distance between the separators can be followed. Therefore, as described above, foreign matter intrusion at the time of increasing the distance between the separators, and sealing material and the like can be prevented. Insufficient sealing due to aging can be effectively prevented, and good power generation performance can be maintained.

A fuel cell according to a tenth configuration is a solid polymer electrolyte membrane fuel cell in which a pair of electrodes are provided on both sides of a solid polymer electrolyte membrane, and the outside thereof is sandwiched between a pair of thin metal plate separators. (For example, the inlet-side oxidizing gas communication hole 41a, the outlet-side oxidizing gas communication hole 41b, the inlet-side fuel gas communication hole 42a, the outlet-side fuel gas communication hole 42b, and the inlet-side cooling medium communication hole in the embodiment. 43a, the outlet side cooling medium communication holes 43b), or on the assumption that insulating members (for example, insulating members 201, 211, 221, 231, 241, 271 in the embodiment) are provided. In addition to the configuration, each of the insulating members of the adjacent separator (for example, the insulating member 201 in the embodiment) has a gap (for example, On the premise of having the gap 203 in the embodiment, each insulating member of the adjacent separator (for example, the insulating members 211 and 221 in the embodiment) seals the gap between the separators. It is characterized by being relatively slidable so as to allow expansion and contraction of the separator interval.
According to this configuration, the expansion and contraction of the separator interval is mechanically absorbed by the relative sliding of the insulating members.
Therefore, since the expansion and contraction of the separator interval can be mechanically absorbed, foreign matter intrusion when the separator interval is increased, prevention of deterioration of the sealing property due to aging deterioration of the sealing material and the like, and reduction of the seal surface pressure are prevented. Can be.

The fuel cell according to the eleventh configuration is characterized in that, in the fuel cell according to the tenth configuration, the insulating members (for example, the insulating members 231 and 241 in the embodiment) are made of a soft material. .
According to this configuration, the expansion and contraction of the separator interval does not restrict the relative approach of the separator because the soft material can elastically contract in the separator laminating direction. It elastically returns in the stacking direction and expands to follow the separator.
Therefore, the expansion and contraction of the separator interval does not restrict the relative approach of the separator because the soft material can elastically contract in the separator laminating direction. Since it returns and extends to follow the separator, it is possible to prevent foreign matter from entering when the separator interval is increased, to prevent deterioration of the sealing property due to deterioration of the sealing material or the like over time, and to prevent reduction of the sealing surface pressure.

A fuel cell according to a twelfth configuration is the fuel cell according to the tenth or eleventh configuration, wherein the inner peripheral end surface of the communication hole is formed of the insulating member (for example, the insulating members 201, 211, 221, and 231 in the embodiment). , 241 and 271).
According to this configuration, it is possible to prevent an electrical short circuit on the inner peripheral end face of the communication hole between the adjacent separators.
Therefore, it is possible to effectively prevent an electrical short circuit on the inner peripheral end surface of the communication hole between the adjacent separators, and to maintain good power generation performance.

A fuel cell according to a thirteenth configuration is the fuel cell according to the tenth to twelfth configurations, wherein one of the insulating members of the adjacent separators (for example, the insulating member flat portion 271b in the embodiment) has a flat shape. The insulating member of the other separator (for example, the insulating member convex portion 271a in the embodiment) which opposes this is characterized in that it has a convex shape.
According to this configuration, the combination of the insulating members is formed such that one is formed in a flat shape and the other is formed in a convex shape. The displacement can be absorbed.
Therefore, the relative position shift of the convex insulating member corresponding to the flat insulating member can be absorbed, so that the productivity is improved.

A fuel cell according to a fourteenth configuration is the same as the fuel cell according to the thirteenth configuration, except that a reaction surface outer peripheral sealing member (for example, an outer peripheral sealing material 52 in the embodiment) is provided so as to surround the reaction surface of the separator. One of the reaction surface outer peripheral seal members (for example, the outer peripheral seal material flat portion 52b in the embodiment) has a flat shape, and the other separator opposes the reaction surface outer peripheral seal member (for example, the outer periphery in the embodiment). The sealing material convex portion 52a) is characterized by having a convex shape.
According to this configuration, one of the combinations of the reaction surface outer peripheral seal members is formed in a flat shape, and the other is formed in a convex shape. The displacement of the relative position of the seal member can be absorbed.
Therefore, the relative position shift of the convex outer peripheral sealing material corresponding to the flat outer peripheral sealing material can be absorbed, and the productivity is improved.

A fuel cell according to a fifteenth configuration is the fuel cell according to the fourteenth configuration, in which an outer portion of the reaction surface outer peripheral sealing member (for example, the outer peripheral sealing material 52 in the embodiment) is entirely covered with the insulating member (for example, , And is covered with the insulating member 271) according to the embodiment.
According to this configuration, the metal exposed portion of the separator in the outer portion of the reaction surface outer peripheral seal member is entirely covered with the insulating member, so that the corrosion resistance is improved and an electrical short circuit between the adjacent separators is prevented. it can.
Therefore, it is possible to improve the corrosion resistance of the separator, effectively prevent an electrical short circuit between adjacent separators, and maintain good power generation performance.

The fuel cell according to a sixteenth configuration is the fuel cell according to the fourteenth or fifteenth configuration, wherein the reaction surface outer peripheral sealing member (for example, the outer peripheral sealing material 52 in the embodiment) and the insulating member (for example, the embodiment) are used. And the insulating member 271) are integrally formed.
According to this configuration, the reaction surface outer peripheral sealing member and the insulating outer edge member can be simultaneously molded.
Therefore, the reaction surface outer peripheral sealing member and the insulating member can be molded at the same time, so that the production cost can be reduced.

A fuel cell according to a seventeenth aspect is the fuel cell according to any one of the fourteenth to sixteenth aspects, wherein both surfaces of an outer portion of the reaction surface outer peripheral sealing member (for example, the outer peripheral sealing material 52 in the embodiment) are entirely covered. It is characterized by being covered with an insulating outer edge member (for example, the insulating member 271 in the embodiment) integrally formed with the reaction surface outer peripheral sealing member.
According to this configuration, since the metal exposed portion of the separator in the outer portion of the reaction surface outer peripheral seal member is entirely covered with the insulating member on both surfaces, the corrosion resistance is further improved, and the electrical connection between the adjacent separators is improved. Short circuit can be prevented more.
Therefore, the corrosion resistance of the separator can be further improved, and an electrical short circuit between the adjacent separators can be more effectively prevented, so that good power generation performance can be maintained.

According to the first aspect of the present invention, it is possible to effectively prevent a liquid junction in the refrigerant flow path and an electrical short circuit between adjacent separators in the reaction gas flow path, so that good power generation performance is more reliably maintained. it can.

According to the second aspect of the present invention, since expansion and contraction of the separator interval can be absorbed, foreign matter intrusion can be prevented when the separator interval is increased, sealing performance is prevented from deteriorating due to aging of the sealing material, and sealing surface pressure is reduced. Reduction can be prevented.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a plan view of a separator 3 constituting a solid polymer electrolyte membrane fuel cell 1 according to the first embodiment.
As shown in FIG. 2, the fuel cell 1 is configured by alternately stacking a separator 3 and an electrode membrane structure 5 in which a solid polymer electrolyte membrane 7 is sandwiched between a pair of electrodes 9. By stacking a plurality of the batteries 1, a fuel cell stack is configured.

As shown in FIG. 1, the separator 3 is formed by pressing a stainless steel plate having a plate thickness of 0.2 to 0.5 mm to form a plurality of concave portions 31 having a constant height at a constant pitch. It is configured to include a plate portion 33 and a flat portion 35 that is in contact with each other via a sealing material at an end located outside of each corrugated plate portion 33.

The separator 3 has an inlet-side oxidant gas communication hole 41a for allowing an oxidant gas to pass therethrough and an upper portion on both ends in the horizontal direction located at the outer peripheral edge in the plane of the separator 3 and a passage for allowing a fuel gas to pass therethrough. An inlet-side fuel gas communication hole 42a is provided, and an inlet-side cooling medium communication hole 43a for allowing a cooling medium to pass therethrough at the center of both ends in the horizontal direction, and a passage for allowing the used cooling medium to pass therethrough. An outlet-side cooling medium communication hole 43b is provided.

Further, the separator 3 has an outlet-side oxidizing gas communication hole 41b for allowing an oxidizing gas to pass therethrough, and a fuel gas for allowing the fuel gas to pass therethrough, at the lower portion in the horizontal direction located in the plane and at the outer peripheral edge. Are provided so as to be diagonal to the inlet-side oxidizing gas communication hole 41a and the inlet-side fuel gas communication hole 42a, respectively.

Then, in the cathode-side separator 3 shown in FIG. 1, the oxidizing gas flows from the inlet-side oxidizing gas communication hole 41 a, then flows into each concave portion 31 of the corrugated plate portion 33 and has one short side of the separator 3. From the right side in FIG. 1 to the other short side (the left side in FIG. 1), the gas flows out from the outlet-side oxidant gas communication hole 41b.
Similarly, also in the anode-side separator (not shown in the plan view), the fuel gas flows from the inlet-side fuel gas communication hole 42a, then flows into each concave portion of the corrugated plate portion, and the short side of the separator. From the side to the other short side, and flows out from the outlet side fuel gas communication hole 42b.

The above-described inlet-side oxidant gas communication hole 41a, inlet-side fuel gas communication hole 42a, inlet-side cooling medium communication hole 43a, outlet-side oxidant gas communication hole 41b, outlet-side fuel gas communication hole 42b, and outlet side The cooling medium communication hole 43b corresponds to the communication hole according to the present invention.

On the front and back surfaces of the separator 3, the corrugated plate 33, the inlet-side oxidant gas communication hole 41a, the outlet-side oxidant gas communication hole 41b, the inlet-side fuel gas communication hole 42a, and the outside of the outlet-side fuel gas communication hole 42b. And a second sealant 53 surrounding the outside of the inlet-side cooling medium communication hole 43a and the outlet side cooling medium communication hole 43b.
Here, the corrugated plate portion 33 is a portion corresponding to the reaction surface of the separator, and the outer peripheral sealing material 52 surrounding the portion corresponding to the outer periphery of the corrugated plate portion 33 in the first sealing material 51 is This corresponds to the reaction surface outer peripheral sealing member according to the present invention.
A portion of the outer peripheral seal member 52 adjacent to the inlet-side oxidant gas communication hole 41a and the outlet-side oxidant gas communication hole 41b has a cut portion for allowing the oxidant gas to flow in or out. Similarly, in the anode-side separator (not shown in the plan view), the sealing portion of the portion of the outer peripheral sealing material 52 adjacent to the inlet side fuel gas communication hole 42a and the outlet side fuel gas communication hole 42b is cut. I have.

Further, an insulating frame-shaped member 61 that covers the outer peripheral surface and the outer peripheral end surface over the entire periphery is provided at the outer peripheral portion of the separator 3.
As shown in FIG. 2, the frame-shaped member 61 includes a main body 61a having a rectangular cross section made of a hard resin material such as polyamide or PTFE, and a material softer and more elastic than the main body 61a, such as rubber. And a stretch absorbing portion 61b having a trapezoidal cross section.

A boundary surface 61A between the main body portion 61a and the elastic absorption portion 61b, and an upper end surface 61bA of the elastic absorption portion 61b are set at lower positions than the upper end surfaces 51A and 53A of the first and second seal materials. The height difference between the upper end surface 61bA and the upper end surfaces 51A, 53A is set to be equal to or less than the compression allowance of the first and second seal members 51, 53.

圧 縮 The compression allowance refers to a crush allowance when a predetermined sealing surface pressure is applied to the separator 3 by crushing the first and second seal materials 51 and 53 at the time of laminating the separators.

Then, when the concave portion 31 of the separator 3 constituting one fuel cell 1 and the concave portion 31 of the separator 3 constituting another fuel cell 1 are sequentially butted, a gap is formed between the concave portion 31 of the separator 3 and the electrode 9. The illustrated trapezoidal cross-section space is an oxidizing gas flow path 71 for flowing an oxidizing gas and a fuel gas flow path 73 for flowing a fuel gas, and is formed by being surrounded by the separator 3. A space having a hexagonal cross section serves as a cooling medium passage 75 for flowing the cooling medium.

At the time of stacking the separators, the first and second sealing members 51 and 53 apply a predetermined sealing surface pressure to the separator 3 to reliably surround the communication holes 41a, 42a, 43a, 41b, 42b and 43b. In order to seal, it is crushed by the compression allowance.
At this time, the expansion / contraction absorbing portion 61b of the frame-shaped member 61 disposed at the outer edge of each separator 3 is also pressed by the separator 3 to a predetermined size, specifically, the first and second sealing members 51 and 53. Is compressed by the amount obtained by subtracting the height difference between the upper end face 61bA and the upper end faces 51A and 53A from the compression allowance.

For this reason, even if the separator interval is widened due to the influence of heat or the like, the elastic absorbing portion 61b of the frame-shaped member 61 elastically returns in the separator laminating direction and expands, and tends to separate from the elastic absorbing portion 61b. It follows the main body 61a of the frame-shaped member 61.
Therefore, even if the separator interval is widened, the frame-shaped members 61 that have been in contact with each other are not separated, so that the intrusion of foreign matter from the outside can be effectively prevented, and the durability of the first and second seal members 51 and 53 is also improved. improves.

In addition, since the expansion / contraction absorber 61b can elastically contract in the separator laminating direction, the relative approach of the separator 3 is not restricted as long as the elastic contraction is possible.
Therefore, even if the first and second sealing materials 51 and 53 or the electrode film structure 5 deteriorates with time and becomes lower in height, the expansion and contraction absorbing portion 61b contracts in the separator laminating direction and can reduce the separator interval. Therefore, the sealing members 51 and 53 and the electrode film structure 3 can be kept in close contact with the separator 3, so that the power generation performance does not deteriorate and power generation does not occur.

In addition, since the frame-shaped member 61 is made of an insulating material, even if the surface of the fuel cell stack gets wet due to wetness or dew condensation, a short circuit does not occur, and a short circuit also occurs due to contact between adjacent separators. It goes without saying that the effect of no longer being obtained is obtained. Further, since the outer peripheral end face of the separator 3 is covered with the insulating material, the electrical short circuit on the outer peripheral end face of the adjacent separator 3 can be similarly prevented.

Further, since the frame-shaped member 61, particularly the main body 61a made of a hard resin material, functions as a reinforcing rib, the deformation of the thin metal separator 3 is effectively performed. Can be prevented.
When a thick separator that does not require a reinforcing function is used instead of the thin metal separator 3, the frame-shaped member 61 may be entirely made of a soft material.

FIG. 3A is a sectional view showing a modification of the first embodiment, and FIG. 3B is a sectional view taken along line BB of FIG. 3A.
Hereinafter, in the description of the present modified example, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2 and the description thereof is omitted.

The frame-shaped member 81 according to the present modified example has a structure in which a stretchable absorbing portion 81b covers the main body portion 81a and a hole 83 is formed in at least one of the stretchable absorbing portions 81b1 extending in parallel with the separator 3.
The main body portion 81a and the expansion and contraction absorption portion 81b are made of, for example, the same material as the main body portion 61a and the expansion and contraction absorption portion 61b in FIG.

The vent hole 83 is for discharging excess gas or dew condensation water between the separators 3. To prevent foreign matter from entering from outside, the holes 83 a and 83 b are located at positions of the openings 83 a and 83 b as shown in FIG. Are shifted in the width direction of the separator (in the vertical direction in FIG. 3B), thereby being bent substantially in a Z-shape.

Also in this modified example, since the frame-shaped member 81 includes the expansion-contraction absorbing portion 81b, similarly to the first embodiment, prevention of foreign matter intrusion when the separator interval is increased, and deterioration of the sealing property due to deterioration with time of the sealing material and the like. Prevention can be achieved.
Note that the frame member 81 may be connected to the second seal material 53, such as the one disposed on the separator 3 located at the lowermost stage in FIG.

FIG. 18A is a cross-sectional view showing another modification of the first embodiment, and FIG. 18B is an enlarged view of the outer peripheral sealing material projection 52a.
Hereinafter, in the description of the present modified example, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2 and the description thereof is omitted.

In the frame-shaped member 261 according to the present modification, the expansion / contraction absorbing portion 261b (insulating outer edge member) covers the main body 261a, and both surfaces of the outer portion of the outer peripheral sealing material 52 of the separator 3, that is, the front and back of the outer portion cover the entire surface. And is covered by the elastic absorption part 261b. Here, the outer peripheral end surface of the separator 3 is covered with a frame-shaped member 261, and the inner peripheral end surface of each of the communication holes 41 a, 42 a, 43 a, 41 b, 42 b, 43 b is covered with a stretch absorbing portion 261 b.

The main body 261a and the expansion / contraction absorber 261b are made of, for example, the same material as the main body 61a and the expansion / contraction absorber 61b in FIG.
Further, the expansion / contraction absorbing portion 261b is formed integrally with the first seal member 51 including the outer peripheral seal member 52, and is also formed integrally with the second seal member 53.
Then, one outer peripheral sealing material flat portion 52b of the adjacent separator 3 is formed in a flat shape, and the other outer peripheral sealing material convex portion 52a is formed in a convex shape. Further, the top of the outer peripheral sealing material projection 52a is formed in an R-shaped cross section.

Also in this modification, the elastic member 261b can be elastically contracted in the separator laminating direction. Therefore, similarly to the first embodiment, prevention of intrusion of foreign matter when the separator interval is increased, and sealing performance due to deterioration with time of the sealing material and the like, as in the first embodiment. Deterioration can be prevented.
In addition, since the outer peripheral end surface of the separator 3 and the inner peripheral end surfaces of the communication holes 41a, 42a, 43a, 41b, 42b, 43b are covered by the frame member 261 and the expansion / contraction absorbing portion 261b, the outer peripheral end surface of the adjacent separator 3 is provided. In addition, it is possible to prevent an electrical short circuit on the inner peripheral end surfaces of the communication holes 41a, 42a, 43a, 41b, 42b, 43b.

In addition, since the metal exposed portion of the separator 3 in the outer portion of the outer peripheral sealing material 52 is entirely covered with the stretch absorbing portion 261b, the corrosion resistance is improved and an electrical short circuit between the adjacent separators 3 is prevented. Can be.
In addition, since the expansion / contraction absorbing portion 261b and the first sealing material 51 and the second sealing material 53 are integrally formed, they can be simultaneously molded, and the production cost can be reduced.

In addition, since the combination of the outer peripheral seal materials 52 is set to be a flat shape on one side and a convex shape on the other, the relative position shift of the outer peripheral seal material convex portion 52a corresponding to the outer peripheral seal material flat portion 52b can be reduced. This can be absorbed, so that the operation of adjusting the seal position and the like become unnecessary, and the productivity is improved.
Further, at the time of laminating the separators, the central portion of the R-shaped cross section at the top of the other outer peripheral sealing material convex portion 52a is strongly pressed against the one outer peripheral sealing material flat portion 52b, so that the sealing performance can be improved.

FIG. 4 is a cross-sectional view showing still another modification of the first embodiment.
Hereinafter, in the description of the present modified example, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2 and the description thereof is omitted.

In the frame-shaped member 91 according to this modification, the cover margin L1 of the main body 91a covering the reaction surface 3A side of the separator 3 is set to be approximately half of the cover margin L2 covering the cooling surface 3B side, and the main body 91a The expansion / contraction absorber 91b is integrated only with the inner edge of the cooling surface.
The main body portion 91a and the expansion / contraction absorbing portion 91b are made of, for example, the same material as the main body portion 61a and the expansion / contraction absorbing portion 61b in FIG.

Also in this modified example, since the frame-shaped member 91 includes the expansion-contraction absorbing portions 91b, similarly to the first embodiment, the prevention of foreign substances from entering when the separator interval is increased, and the deterioration of the sealing property due to the deterioration over time of the sealing material and the like. Prevention can be achieved.
Furthermore, since the expansion and contraction absorption portion 91b of the frame-shaped member 91 according to the present modification has a higher protruding height from the separator 3 than the expansion and contraction absorption portion 61b of the first embodiment, more expansion and contraction allowance can be taken. In particular, it is excellent in followability when the separator interval is increased.

Next, a fuel cell according to a second embodiment of the present invention will be described.
FIG. 5 is a sectional view of a main part of the fuel cell.
Hereinafter, in the description of the present embodiment, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2, and description thereof will be omitted.

額 The frame-shaped member 101 according to the present embodiment is different from the first embodiment in which elastic deformation is used to absorb expansion and contraction in the first embodiment and its modification in mechanically absorbing expansion and contraction in the separator laminating direction.

The frame-shaped member 101 has a projecting ridge 101a projecting from the base 101b, and has a convex cross-sectional shape. The ridge 101a is inside the fuel cell stack along the separator laminating direction (right side in FIG. 5). And the outside (the left side in FIG. 5).
In addition, two adjacent frame members 101 are not normally in contact with a surface 101B parallel to the separator 3, but are in contact with a surface 101A parallel to the separator laminating direction.

That is, the interval between the separators is defined by the height of the first and second seal members 51 and 53 (only the second seal member 53 is shown in FIG. 5) from the separator 3, and the height of the protrusion is The height of the protrusion 101a from the separator 3 and the height of the base 101b are set larger than the height of the protrusion.
As a result, a gap 103 is formed between the base 101b of one adjacent frame-shaped member 101 and the ridge 101a of the other frame-shaped member 101.

According to this configuration, the movement of expanding and contracting the separator interval is caused by the relative sliding of the face 101A of one adjacent frame-shaped member 101 and the face 101A of the other frame-shaped member 101 without separation. The gap 103 between the shaped members 101 is absorbed only by widening.
Therefore, similarly to the first embodiment, it is possible to prevent foreign matter from entering when the separator interval is increased and to prevent deterioration of the sealing property due to the deterioration with time of the sealing material.

Furthermore, in the present embodiment, focusing on the two adjacent frame members 101, the surfaces 101B parallel to the separator 3 do not contact each other, and therefore, between these two frame members 101, along the separator laminating direction. No load occurs.
Therefore, the compressive load acting on the first and second seal members 51 and 53 is not dispersed to the frame-shaped member 101, and a decrease in the seal surface pressure can be effectively prevented.

FIG. 6 is a cross-sectional view illustrating a modification of the second embodiment.
Hereinafter, in the description of the present modified example, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2 and the description thereof is omitted.

Also in the frame-shaped member 111 according to this modification, the surface 111A of the adjacent one of the frame-shaped members 111 and the surface 111A of the other frame-shaped member 111 are relatively slid without being separated from each other, similarly to the configuration of FIG. Meanwhile, since the gap 113 between the frame members 111 is widened and narrowed, as in the second embodiment, prevention of foreign matter intrusion when the separator interval is increased, prevention of deterioration of sealing properties due to aging of the sealing material and the like, and sealing surface The pressure can be prevented from decreasing.

Furthermore, in this modification, the frame-shaped member 111 having the same cross-sectional shape is provided on the outer edge of each separator 3 in that the frame-shaped member 111 having the same cross-sectional shape is disposed in the same shape at the outer edge of each separator 3. Is different from the second embodiment in which the protrusions 101a are alternately arranged in the direction in which the protrusions 101a protrude in the separator laminating direction.
Therefore, when the frame-shaped member 111 is integrally molded with the outer edge of the separator 3 by injection molding, molding can be performed with only one type of mold, and the production cost can be reduced.

FIG. 7 is a cross-sectional view illustrating another modified example of the second embodiment.
Hereinafter, in the description of the present modified example, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2 and the description thereof is omitted.

In the frame-shaped member 121 according to the present modification, a concave portion 123 is formed on the end surface of the separator 3 on the cooling surface 3B side, and a convex portion 125 having a shape that can be fitted into the concave portion 123 is formed on the reaction surface 3A of the separator 3. It protrudes from the end face on the side.

According to this configuration, it is possible to absorb expansion and contraction by widening and narrowing the gap 127 between the frame-shaped members 121 while the recess inner surface 123A parallel to the separator laminating direction and the protrusion outer surface 125B relatively slide without being separated from each other. At the same time, the frame-like members 121 having the same cross-sectional shape are arranged in the same form on the outer edge of each separator 3. Therefore, similarly to the modification of FIG. It is possible to prevent the deterioration of the sealing performance due to the deterioration with time, prevent the reduction of the sealing surface pressure, and reduce the production cost.

Further, according to the frame-shaped member 121 according to the present modification, the concave portion 123 of the frame-shaped member 121 disposed on the adjacent one of the separators 3 has the convex portion of the frame-shaped member 121 disposed on the other of the separators 3. When 125 is fitted, the relative position between the separators 3 is automatically adjusted, so that the workability at the time of assembly and maintenance is improved.
That is, in the present modification, the concave portion 123 and the convex portion 125 constitute a separator positioning unit according to the present invention.

Next, a fuel cell according to a third embodiment of the present invention will be described.
FIG. 8 is a sectional view of a main part of the fuel cell.
Hereinafter, in the description of the present embodiment, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2, and description thereof will be omitted.

In the frame-shaped member 131 according to the present embodiment, the end surface 131A on the cooling surface 3B side of the separator 3 and the end surface 131B on the reaction surface 3A side of the separator 3 are both inside the cooling surface 3B and the reaction surface 3A. It is a mortar-shaped inclined surface that is inclined downward (downward to the right in the cross section of the main part in FIG. 8).
In the present embodiment, the end face 131A and the end face 131B constitute separator positioning means.

According to this configuration, the end surface 131A of the adjacent one of the frame members 131 and the end surface 131B of the other frame member 131 relatively slide without being separated from each other, so that expansion and contraction of the separator interval is absorbed. The relative positions between the separators 3 are also automatically aligned, and the frame-like members 131 having the same cross-sectional shape are arranged in the same form at the outer edge of each separator 3. To prevent foreign matter from entering when the separator interval is increased, to prevent deterioration of sealing performance due to deterioration of sealing material over time, to prevent reduction of sealing surface pressure, to reduce production cost, and to improve workability during assembly and maintenance. be able to.

Next, a fuel cell according to a fourth embodiment of the present invention will be described.
FIG. 9 is a sectional view of a main part of the fuel cell.
Hereinafter, in the description of the present embodiment, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2, and description thereof will be omitted.

The frame-shaped member 141 according to the present embodiment is formed, for example, from the same soft material as the elastic absorption member 61b in FIG.
In the frame-shaped member 141, the separator positioning means is constituted by the triangular cross-sectional groove 143 formed on the end surface on the cooling surface 3B side and the triangular protruding ridge 145 formed on the end surface on the reaction surface 3A side. .

According to this configuration, the frame-like member 141 elastically expands and contracts, so that the expansion and contraction of the separator interval is absorbed, and the triangular groove portion 143 of the frame-like member 141 disposed on the adjacent one of the separators 3 has the other end. When the triangular ridges 145 of the frame-shaped member 141 disposed on the separators 3 are fitted, the relative positions between the separators 3 are automatically aligned, and the outer edges of the separators 3 have the same cross-sectional shape. Since the frame-shaped members are arranged in the same form, as in the configuration of FIG. 8, it is possible to prevent foreign matter from entering when the separator interval is increased, to prevent deterioration of the sealing property due to the aging of the sealing material, and to reduce the sealing surface pressure. Prevention of reduction, reduction of production cost, and improvement of workability during assembly and maintenance can be achieved.

In the above-described configuration in which the frame-shaped members 61, 81, 91, 101, 111, 121, 131, and 141 are provided on the outer edge of the separator, as shown in FIG. 3a, 3b and 3c may be formed.
According to this configuration, the bent portions 3a, 3b, and 3c function as reinforcing ribs and retaining members for the frame members 61, 81, 91, 101, 111, 121, 131, and 141. Deformation of the separator 3 and detachment of the frame-shaped members 61, 81, 91, 101, 111, 121, 131, 141 can be effectively prevented.

Next, a fuel cell according to a fifth embodiment of the present invention will be described.
FIG. 11 is a sectional view of a main part of the fuel cell.
Hereinafter, in the description of the present embodiment, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2, and description thereof will be omitted.

In this fuel cell, the inlet-side oxidant gas communication hole 41a, the inlet-side fuel gas communication hole 42a, the inlet-side cooling medium communication hole 43a, the outlet-side oxidant gas communication hole 41b, and the outlet-side fuel gas communication formed in the separator 3. An annular insulating member 201 made of resin, rubber, or the like that covers the inner peripheral surface and the inner peripheral end surface is provided around the hole 42b and the outlet-side cooling medium communication hole 43b.
FIG. 11 shows only the outlet side fuel gas communication hole 42b.

According to this configuration, it is possible to effectively prevent a liquid junction in the cooling medium flow path and an electrical short circuit between adjacent separators in the reaction gas flow path.
In particular, since the fuel cell according to the present embodiment uses the thin metal separator 3, the interval between the separators is short, and the structure is disadvantageous in preventing an electrical short circuit between the separators. , The effect is exceptional.
Moreover, since the insulating member 201 also functions as a reinforcing rib around the communication hole of the thin metal separator 3, the deformation can be effectively prevented.

In addition, the height of the insulating member protruding from the front and rear surfaces of the separator is set so that the insulating member 201 provided on the adjacent one of the separators 3 and the other insulating member 201 do not come into contact with each other. Since the gap 203 is set between the members 201, the gap 203 is widened and narrowed, so that the structure can absorb the expansion and contraction of the separator interval.

For this reason, it is possible to prevent foreign substances from entering when the separator interval is increased, to prevent deterioration of the sealing property due to the deterioration with time of the sealing material and the like, and to prevent reduction of the sealing surface pressure.
Furthermore, since the insulating members 201 having the same cross-sectional shape are provided in the same form around the communication holes of the separators 3, when the insulating members 201 are integrally formed with the separator 3 by injection molding, one kind of metal is used. Molding can be performed using only a mold, and production costs can be reduced.

FIG. 12 and FIG. 13 are cross-sectional views showing a modification of the fifth embodiment.
Hereinafter, in the description of the present modified example, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2 and the description thereof is omitted.

In the modification of FIG. 12, for example, an annular insulating member 211 having the same material and the same cross-sectional shape as the frame-shaped member 101 of FIG. 5 is provided around the communication holes 41a, 42a, 43a, 41b, 42b, and 43b. In the modified example of FIG. 13, an annular insulating member having the same material and the same cross-sectional shape as the frame member 111 of FIG. 6, for example, is provided around the communication holes 41a, 42a, 43a, 41b, 42b, and 43b. The sex member 221 is provided.

According to these configurations, as in the configuration of FIG. 11, the liquid junction in the cooling medium flow path, the electrical short circuit between adjacent separators in the reaction gas flow path, the prevention of foreign substances from entering when the separator interval is increased, the sealing material Thus, it is possible to prevent the deterioration of the sealing performance due to the deterioration with time and to prevent the reduction of the seal surface pressure.
In particular, in the modification of FIG. 13, since the insulating members 221 disposed around the communication holes 41a, 42a, 43a, 41b, 42b, 43b all have the same cross-sectional shape, the insulating member 221 is formed by injection molding. When the member 221 is integrally molded with the separator, molding can be performed using only one type of mold, and the production cost can be reduced.

FIGS. 14 and 15 are cross-sectional views showing still another modification of the fifth embodiment.
Hereinafter, in the description of the present modified example, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2 and the description thereof is omitted.

In the modification of FIG. 14, for example, an annular insulating member 231 having the same material and the same cross-sectional shape as the frame-shaped member 61 of FIG. 2 is provided around the communication holes 41a, 42a, 43a, 41b, 42b, and 43b. In the modified example of FIG. 15, a flange is formed around each of the communication holes 41a, 42a, 43a, 41b, 42b, 43b, for example, at one open end made of the same material as the elastic absorption part 61b of FIG. An annular insulating member 241 having a portion 241a is provided.

According to these configurations, similarly to the configuration of FIG. 11, the liquid junction in the cooling medium flow path, the prevention of electrical short circuit between adjacent separators in the reaction gas flow path, the prevention of foreign substances from entering when the separator interval is increased, the sealing material, etc. It is also possible to prevent the deterioration of the sealing property due to the deterioration with time, prevent the reduction of the sealing surface pressure, and reduce the production cost when the insulating members 231 and 241 are integrally formed with the separator by injection molding.

Next, a fuel cell according to a sixth embodiment of the present invention will be described.
FIG. 19A is a cross-sectional view of a main part of the fuel cell, and FIG. 19B is an enlarged view of the outer peripheral sealing material projection 52a.
Hereinafter, in the description of the present modified example, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG.
In this fuel cell, both surfaces of the outer portion of the outer peripheral sealing material 52 of the separator 3, that is, the front and back of the outer portion are entirely covered with the insulating member 271. Further, the outer peripheral end surface of the separator 3 and the inner peripheral end surfaces of the communication holes 41a, 42a, 43a, 41b, 42b, 43b are also covered by the insulating member 271.
The insulating member 271 is made of a soft and elastic material such as rubber, for example, like the expansion and contraction absorbing portion 61b of FIG.

Further, the insulating member 271 is formed integrally with the first seal member 51 including the outer peripheral seal member 52, and is also formed integrally with the second seal member 53.
Then, one outer peripheral sealing material flat portion 52b (insulating member flat portion 271b) of the adjacent separator 3 is formed in a flat shape, and the other outer peripheral sealing material convex portion 52a (insulating member convex portion 271a) has a convex shape. Is formed. Further, the top of the outer peripheral sealing material projection 52a is formed in an R-shaped cross section.
An outer peripheral portion of the separator 3 and an inner peripheral portion of each of the communication holes 41a, 42a, 43a, 41b, 42b, 43b are formed with a step portion 3d, and the outer peripheral portion of the separator 3 and each of the communication holes are formed by the step portion 3d. The inner peripheral portions of 41a, 42a, 43a, 41b, 42b, 43b are changed to the reaction surface 3A side of the separator 3. A gap 273 is formed between the reaction surfaces 3A of the adjacent separators 3.

According to this configuration, it is possible to effectively prevent an electrical short circuit on the outer peripheral end surface of the adjacent separator 3 and the inner peripheral end surfaces of the communication holes 41a, 42a, 43a, 41b, 42b, 43b.
In addition, since the metal exposed portion of the separator 3 in the outer portion of the outer peripheral sealing material 52 is entirely covered with the insulating member 271 on both surfaces, the corrosion resistance is improved and an electrical short circuit between the adjacent separators 3 is prevented. can do.
Further, since the insulating member 271 and the first sealing material 51 and the second sealing material 53 are integrally formed, they can be simultaneously molded, and the production cost can be reduced.

In addition, since one of the combinations of the outer peripheral seal materials 52 is formed in a flat shape and the other is formed in a convex shape, the relative positional shift of the outer peripheral seal material convex portions 52a corresponding to the outer peripheral seal material flat portions 52b is reduced. This can be absorbed, so that the operation of adjusting the seal position and the like become unnecessary, and the productivity is improved.
Further, at the time of laminating the separators, the central portion of the R-shaped cross section at the top of the other outer peripheral sealing material convex portion 52a is strongly pressed against the one outer peripheral sealing material flat portion 52b, so that the sealing performance can be improved.

In addition, since the step portion 3d also functions as a reinforcing rib around the outer edge portion and the periphery of the communication hole of the thin metal separator 3, the deformation can be effectively prevented.
Further, since the step height from the front and back surfaces of the separator 3 is set so as not to contact each other between the reaction surfaces 3A of the adjacent separators 3, that is, the gap 273 is formed. By widening, the structure can also absorb the expansion and contraction of the space between the separators 3.
For this reason, it is possible to prevent foreign matter from entering when the separator interval is increased, to prevent deterioration of sealing performance due to deterioration of the sealing material with time, and to prevent reduction in sealing surface pressure.

FIG. 16 is a sectional view showing the sixth embodiment.
Hereinafter, in the description of the present embodiment, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2, and description thereof will be omitted.

The frame-shaped member 251 according to the present embodiment covers the outer periphery of the main body 251a disposed on the outer edge of the separator 3 with a stretchable absorbing portion 251b made of a vibration-proof material such as rubber, and the stretchable absorbing portion 251b is attached to the vehicle body. This also serves as a mount part.

According to this configuration, similarly to the configuration of FIG. 2, it is possible to prevent foreign matter from entering when the separator interval is increased, and to prevent deterioration of the sealing property due to the deterioration with time of the sealing material.
Furthermore, when the fuel cells 1 are stacked in the horizontal direction (horizontal direction) and placed on the mounting surface 300, the expansion / contraction absorbing portion 251 b of the frame-shaped member 251 comes into contact with the mounting surface 300 of the fuel cell 1, thereby providing an anti-vibration function. Therefore, it is not necessary to separately mount the vibration isolating component to the fuel cell stack, and the cost can be reduced.

Here, the expansion-contraction absorber 251b made of a vibration-proof material may be provided for each of one or more fuel cells.
The modified example shown in FIG. 17 shows a fuel cell stack in which an expansion-contraction absorber 251b made of an anti-vibration material is provided for each fuel cell. The elastic absorbers 251c made of the same material as the elastic absorbers 61b of FIG. 2 are alternately arranged for every other separator 3.

In the above-described embodiments and modified examples, the separator 3 is made of stainless steel, but may be made of a metal material such as titanium or a carbonaceous material.

1 is a plan view illustrating a separator of a polymer electrolyte membrane fuel cell according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of a fuel cell stack configured by stacking a plurality of solid polymer electrolyte membrane fuel cells including the separator of FIG. 1 at a position corresponding to line AA in FIG. 1. (A) is a sectional view of a main part showing a modification of the first embodiment, and (b) is a BB sectional view of (a). It is a principal part sectional view which shows another modification of 1st Embodiment. It is principal part sectional drawing which shows 2nd Embodiment of this invention. It is a principal part sectional view showing a modification of a 2nd embodiment. It is a principal part sectional view which shows the other modification of 2nd Embodiment. It is principal part sectional drawing which shows 3rd Embodiment of this invention. It is a principal part sectional view showing a modification of a 3rd embodiment. It is a principal part sectional view showing another modification of a 3rd embodiment. It is principal part sectional drawing which shows 4th Embodiment of this invention. It is a principal part sectional view showing a modification of a 4th embodiment. It is principal part sectional drawing which shows the other modification of 4th Embodiment. It is principal part sectional drawing which shows 5th Embodiment of this invention. It is principal part sectional drawing which shows the modification of 5th Embodiment. It is principal part sectional drawing which shows 6th Embodiment of this invention. It is a principal part sectional view showing a modification of a 6th embodiment. (A) is a principal part sectional view showing another modification of the first embodiment, and (b) is an enlarged view of an outer peripheral sealing material convex portion. (A) is sectional drawing of the principal part which shows 5th Embodiment, (b) is an enlarged view of an outer periphery sealing material convex part.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Fuel cell 3 Separator 7 Solid polymer electrolyte membrane 9 Electrode 41a Inlet side oxidant gas communication hole 41b Outlet side oxidant gas communication hole 42a Inlet side fuel gas communication hole 42b Outlet side fuel gas communication hole 43a Inlet side cooling medium communication hole 43b Outlet side cooling medium communication hole 52 Outer peripheral seal material (reactor surface outer peripheral seal member)
52a Outer peripheral seal material convex (convex shape)
52b Peripheral seal material flat part (flat shape)
61, 81, 91, 101, 111, 121, 131, 141, 251, 261 Frame member 61a, 81a, 91a, 261a Main body (portion made of hard material)
61b, 81b, 91b, 261b (insulating outer edge member) Expansion / contraction absorber (portion made of soft material)
123 recess (part of positioning means)
125 convex part (part of positioning means)
131A end face (part of positioning means)
131B end face (part of positioning means)
143 Triangular groove section (part of positioning means)
145 Triangular ridge section (part of positioning means)
201, 211, 221, 231, 241, 271 Insulating member 203 Gap 271a Insulating member convex portion (convex shape)
271b Flat part of insulating member (flat shape)

Claims (2)

In a fuel cell in which a pair of electrodes are provided on both sides of a solid polymer electrolyte membrane and the outside of which is sandwiched between a pair of thin metal plate separators, an insulating member is provided around a communication hole formed in the separator. A fuel cell, characterized in that: 2. The fuel cell according to claim 1, wherein each of the insulating members of the adjacent separators has a gap in a direction in which the separators are stacked.

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