JP3739769B2 - Fuel cell - Google Patents

Description

  The present invention relates to a solid polymer electrolyte membrane type 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 stretching and absorbing in the separator stacking direction.

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 of a fuel gas (for example, hydrogen) is provided on one surface of a separator disposed to face one electrode, and an oxidant gas (for example, oxygen) is disposed on one surface of a separator disposed to face the other electrode. Air), and a cooling medium channel is provided on the surface opposite to the surface facing one of the electrodes.

When 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. Electrons generated during this time are taken out to an external circuit and used as direct current electric energy.
Since the oxidant gas is supplied to the other electrode, hydrogen ions, electrons and oxygen react to generate water.
The surface opposite to the electrode reaction surface of the separator 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 the flow paths is important.
As a seal part, a reaction gas and a cooling medium are distributed around each of the fuel cells of the fuel cell stack, around a communication hole formed in the separator, a pair of solid polymer electrolyte membranes and a pair of both sides thereof. There are an outer periphery of an electrode film structure composed of electrodes, an outer periphery of a coolant channel surface of the separator, an outer periphery of the front and back surfaces of the separator, and the sealing material is soft and has a moderately repulsive force such as organic rubber Adopted.

By the way, when a fuel cell stack is configured by laminating a plurality of sets of fuel cells, and this fuel cell stack is mounted on a vehicle, depending on the installation position, water droplets or the like may scatter and the fuel cell may get wet, or between separators Dust may enter the gap.
However, the sealing material can prevent the water and dust from entering the reaction gas flow path and the cooling medium flow path.

However, when the separators are stacked, the thickness of the electrode membrane structure varies, the separators (particularly, metal thin separators) are warped or distorted, and the compressive load received from both ends of the fuel cell stack is insignificant. If it is uniform, the separators are not stacked in parallel, and tilting and twisting occur, resulting in an imbalance in the compression amount of each sealing material, and the sealing performance of a sealing material with a small compression amount is deteriorated.
In addition, when laminating separators, it is difficult to accurately stack the separators without shifting the relative positions along the electrode reaction surfaces.

As a countermeasure against the above, for example, by providing a frame member made of resin on the outer edge portion of the separator, it is possible to prevent foreign matter from entering into the gap between the separators and to allow the separators to be stacked in parallel (for example, Patent Document 1, Patent Document 2 and Patent Document 3).
Japanese Patent Laid-Open No. 10-074530 Japanese Patent Application Laid-Open No. 07-249417 JP-A 61-279069

However, if the sealing material or the electrode film structure contracts in the separator stacking direction due to deterioration with time or the fuel cell expands or contracts due to the influence of heat or the like, the following problems occur.
For example, if the protruding height of the sealing material from the separator is lower than the protruding height of the frame-like member, the shrinkage of the separator interval is regulated by the frame-like member, so there is a gap between the separator and the sealing material or the electrode film structure. May occur, resulting in a decrease in power generation performance and thus inability to generate power.

  On the other hand, if the separator spacing increases due to the influence of heat, etc., the sealing material made of rubber or the like elastically recovers and expands in the separator stacking direction. However, since the frame-shaped member made of resin or the like does not extend in the separator stacking direction, it cannot follow the spread of the separator interval. For this reason, a clearance gap arises between frame-shaped members, and there exists a possibility that a foreign material may penetrate | invade from there.

Furthermore, in the cooling medium flow path, it is necessary to prevent a liquid junction through which a current flows through the cooling medium, and in the reaction gas flow path, it is necessary to prevent an adjacent separator from being electrically short-circuited.
In particular, in the case of a fuel cell using a thin metal separator, the distance between the separators is short, so that there is a possibility that foreign substances such as dust and carbon particles are mixed in the reaction gas. It is desirable to take special measures to prevent a short circuit.

  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 the separator stacking direction in a solid polymer electrolyte membrane fuel cell and a fuel cell stack. The purpose is to facilitate positioning during stacking and to insulate the periphery of the communication hole formed in the separator.

To achieve the above object, in the fuel cell according to claim 1, a solid polymer electrolyte membrane type in which a pair of electrodes are provided on both sides of a solid polymer electrolyte membrane and the outside is sandwiched between a pair of metal sheet separators. In the fuel cell, communication holes formed in the separator and sealed at the periphery (for example, an inlet-side oxidant gas communication hole 41a, an outlet-side oxidant gas communication hole 41b, an inlet-side fuel gas communication hole 42a, and an outlet in the embodiment) Insulating member (for example, insulation in the embodiment) that covers the inner peripheral end face of the communication hole around the side fuel gas communication hole 42b, the inlet side cooling medium communication hole 43a, and the outlet side cooling medium communication hole 43b) Characteristic members 201, 211 , 231, 241 , 271).

  According to this configuration, it is possible to prevent a liquid junction in the cooling medium flow path and an electrical short circuit between 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, there is a gap in the stacking direction of the separator between the insulating members of the separators adjacent to each other (for example, the insulating member 201 in the embodiment). (e.g., gaps 203 in the embodiment), characterized in that is formed.

According to this configuration, expansion and contraction of the separator interval can be absorbed by widening and narrowing the gap in the stacking direction of the separator.
The invention described in claim 3 is characterized in that insulating members around the communication hole (for example, insulating members 231, 241, 261 in the embodiment) are in contact with each other between the adjacent separators.
According to this configuration, it is possible to prevent foreign matter from entering when the separator interval is increased.
According to a fourth aspect of the present invention, the insulating member around the communication hole (for example, the insulating member 211 in the embodiment) is configured to be relatively slidable between the adjacent separators. Features.
According to this configuration, it is possible to prevent foreign matter from entering when the separator interval is increased.
According to the fifth aspect of the invention, between the adjacent separators, one of the insulating members around the communication hole (for example, the insulating member 211 in the embodiment) is convex (for example, the outer peripheral sealing material in the embodiment) The projecting portion 52a) has a flat shape on the other side (for example, the outer peripheral sealing material flat portion 52b in the embodiment).
According to this structure, the relative position shift of the convex part with respect to a flat-shaped part can be absorbed.
The invention described in claim 6 is characterized in that a step (for example, a step portion 3d in the embodiment) is provided around the communication hole of the separator.
According to this configuration, the step can function as a reinforcing rib.

In addition, a fuel cell and a fuel cell stack having the following configurations may be employed.
The fuel cell of the first configuration is provided with a pair of electrodes (for example, the electrode 9 in the embodiment) on both sides of a solid polymer electrolyte membrane (for example, the solid polymer electrolyte membrane 7 in the embodiment), 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), the gap between the separators is expanded and contracted at the outer edge portion of the separator. Insulating frame-like members that allow the image (for example, frame-like members 61, 81, 91, 101, 111, 121, 131, 141, 251, 261 in the embodiment) are provided.
According to this configuration, no gap is generated between the separator and the frame-like member for the movement in which the separator interval is widened, and the movement for the movement in which the separator interval is narrowed. It will not be blocked by the frame-shaped member.
Therefore, there is no gap between the separator and the frame-like member for the movement that increases the separator interval, and the movement is prevented by the frame-like member for the movement that reduces the separator interval. As a result, it is possible to effectively prevent foreign matter intrusion when the separator interval is increased and seal failure due to deterioration over time of the sealing material, etc., and maintain good power generation performance.

The fuel cell of the second configuration is configured so that the frame-shaped members (for example, the frame-shaped members 101, 111, 121, 131 in the embodiment) can slide relative to each other in the fuel cell of the first configuration. It is characterized by being.
According to this configuration, the width of the separator interval is mechanically absorbed by the relative sliding of the frame-shaped members.
Accordingly, since the width of the separator interval can be mechanically absorbed by the relative sliding of the frame-like members, as in the above case, foreign matter intrusion when the separator interval increases and seal failure due to deterioration with time of the sealing material, etc. It can be effectively prevented and good power generation performance can be maintained.

The fuel cell of the third configuration is the fuel cell of the first or second configuration, wherein the separator is made of metal, and the frame-shaped member (for example, the frame-shaped members 61, 81, 91, 261) is composed of a hard material (for example, main body portions 61a, 81a, 91a, 261a in the embodiment) and a soft material (for example, stretchable absorption portions 61b, 81b, 91b, 261b in the embodiment). It is characterized by.
According to this configuration, since the soft member can be elastically contracted in the separator stacking direction, relative approach of the separator is not restricted.
Moreover, with respect to the spread of the separator interval, the soft member elastically returns in the separator stacking direction and expands to follow the separator.
Accordingly, since the soft member can be elastically contracted in the separator stacking direction, the relative approach of the separator is not restricted, and the soft member is elastically restored and expanded in the separator stacking direction with respect to the widening of the separator interval. Since it follows the separator, it is possible to effectively prevent foreign material intrusion when the separator interval increases and seal failure due to deterioration over time of the sealing material, etc., and maintain good power generation performance.

The fuel cell of the fourth configuration is the fuel cell of the first configuration, wherein the frame-shaped member is separator positioning means (for example, a combination of the concave portion 123 and the convex portion 125 in the embodiment, the end surface 131A and the end surface 131B, And a combination of a cross-sectional triangular groove part 143 and a cross-sectional triangular ridge part 145).
According to this structure, the shift | offset | difference of the relative position between separators which may arise at the time of separator lamination | stacking can be prevented.
Therefore, since the separator alignment is automatically performed when the separators are stacked, workability during assembly and maintenance is improved.

The fuel cell of the fifth configuration is the fuel cell of any one of the first to fourth configurations, wherein the outer peripheral end surface of the separator is the frame-shaped member (for example, the frame-shaped members 61, 81, 91, 101, 111, 121, 131, 141, 251, 261).
According to this structure, the electrical short circuit in the outer peripheral end surface between adjacent separators can be prevented.
Therefore, an electrical short circuit at the outer peripheral end face between adjacent separators can be effectively prevented, and good power generation performance can be maintained.

In the fuel cell having the sixth structure, in the fuel cell having any one of the first to fifth structures, a reaction surface outer peripheral seal member (for example, the outer peripheral seal material 52 in the embodiment) is provided so as to surround the reaction surface of the separator. The outer surface of the reaction surface outer periphery sealing member is covered with an insulating outer edge member (for example, the expansion / contraction absorbing portion 261b in the embodiment) over the entire surface.
According to this configuration, the exposed metal 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, so that the corrosion resistance is improved and an electrical short circuit between adjacent separators is achieved. Can be prevented.
Therefore, the corrosion resistance of the separator can be improved, and an electrical short circuit between adjacent separators can be effectively prevented, and good power generation performance can be maintained.

The fuel cell of the seventh configuration is the same as that of the fuel cell of the sixth configuration, with the reaction surface outer periphery sealing member (for example, the outer peripheral seal material 52 in the embodiment) having both outer surfaces covering the entire surface. It is characterized by being covered with an insulating outer edge member (for example, the expansion and contraction absorbing portion 261b in the embodiment) configured integrally with the seal member.
According to this configuration, the exposed metal 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, so that the corrosion resistance is further improved and the electrical conductivity between the adjacent separators is improved. Can prevent a short circuit.
Therefore, the corrosion resistance of the separator can be further improved, and an electrical short circuit between adjacent separators can be more effectively prevented, and good power generation performance can be maintained. Moreover, since the reaction surface outer periphery sealing member and the insulating outer edge member can be molded simultaneously, the production cost can be reduced.

In the fuel cell of the eighth configuration, in the fuel cell of the sixth or seventh configuration, one of the reaction surface outer peripheral seal members (for example, the outer peripheral seal material flat portion 52b in the embodiment) is adjacent to the separator. The reaction surface outer peripheral sealing member (for example, the outer peripheral sealing material convex portion 52a in the embodiment) of the other separator that is flat and has a flat shape is convex.
According to this configuration, since the combination of the reaction surface outer periphery sealing members is set to have a flat shape on one side and a convex shape on the other side, the reaction surface outer periphery sealing member corresponding to the flat reaction surface outer periphery sealing member is set. A shift in the relative position of the seal member can be absorbed.
Therefore, since the shift of the relative position of the convex reaction surface outer periphery seal member corresponding to the flat reaction surface outer periphery seal member can be absorbed, productivity is improved.

A ninth configuration is a fuel cell stack configured by stacking a plurality of fuel cells of any one of the first to eighth configurations, wherein the frame-shaped member has a separator interval while sealing 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 generated between the separator and the frame-like member with respect to the movement in which the separator interval is widened. In addition, the movement in which the separator interval is narrowed is not prevented by the frame-like member.
Therefore, not only within a single fuel cell but also between adjacent fuel cells, it becomes possible to follow the width of the separator interval. It is possible to effectively prevent a sealing failure due to deterioration with time and maintain good power generation performance.

A fuel cell of a tenth configuration 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 metal sheet separators. Communication holes (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, the outlet side fuel gas communication hole 42b, and the inlet side cooling medium communication hole in the embodiment) 43a, on the premise that insulating members (for example, insulating members 201, 211, 221, 231, 241, 271 in the embodiment) are provided around the outlet side cooling medium communication hole 43b), or In addition to the configuration, each of the insulating members of the separators adjacent to each other (for example, the insulating member 201 in the embodiment) has a gap in the stacking direction of the separators (for example, Assuming that there is a gap 203) in the embodiment, each insulating member of the separators adjacent to each other (for example, the insulating members 211 and 221 in the embodiment) seals the gap between the separators. It is configured to be capable of relative sliding 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 as the insulating members slide relative to each other.
Accordingly, since the expansion and contraction of the separator interval can be mechanically absorbed, it is possible to prevent foreign matter from entering when the separator interval is increased, to prevent deterioration of the sealing performance due to aging of the sealing material, and to prevent reduction of the seal surface pressure. Can do.

The eleventh configuration fuel cell is the tenth configuration fuel cell, wherein 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 be elastically contracted in the separator stacking direction. Elastically recovers in the stacking direction and extends to follow the separator.
Therefore, the expansion / contraction of the separator interval does not restrict the relative approach of the separator because the soft material can be elastically contracted in the separator stacking direction, and the soft material is elastic in the separator stacking direction with respect to the spread of the separator interval. Since it recovers and expands to follow the separator, it is possible to prevent foreign matter from entering when the separator interval is increased, to prevent deterioration of sealing performance due to aging deterioration of the sealing material and the like, and to prevent reduction of the seal surface pressure.

The fuel cell of the twelfth configuration is the fuel cell of the tenth or eleventh configuration, wherein the inner peripheral end surface of the communication hole is the insulating member (for example, the insulating members 201, 2111, 211, 231 in the embodiment). , 241, 271).
According to this structure, the electrical short circuit in the inner peripheral end surface of the communicating hole between adjacent separators can be prevented.
Therefore, an electrical short circuit at the inner peripheral end face of the communication hole between adjacent separators can be effectively prevented, and good power generation performance can be maintained.

The fuel cell of the thirteenth configuration is the fuel cell of the tenth to twelfth configurations, wherein one of the insulating members of the adjacent separator (for example, the insulating member flat portion 271b in the embodiment) is flat. And the said insulating member (for example, insulating member convex part 271a in embodiment) of the other separator which opposes this is convex shape, It is characterized by the above-mentioned.
According to this configuration, since the combination of the insulating members is formed in a flat shape on one side and a convex shape on the other side, the relative shape of the convex insulating members corresponding to the flat shape insulating member is relatively small. Misalignment can be absorbed.
Therefore, since the shift in the relative position of the convex insulating member corresponding to the flat insulating member can be absorbed, productivity is improved.

The fuel cell of the fourteenth configuration is the fuel cell of the thirteenth configuration, wherein a reaction surface outer peripheral seal member (for example, the outer peripheral seal 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 counteracts the reaction surface outer peripheral seal member (for example, the outer periphery in the embodiment). The sealing material convex portion 52a) has a convex shape.
According to this configuration, since the reaction surface outer peripheral seal member is formed in a flat shape on one side and a convex shape on the other side, the outer periphery of the convex reaction surface corresponding to the flat reaction surface outer peripheral seal member A shift in the relative position of the seal member can be absorbed.
Therefore, since the shift of the relative position of the convex outer peripheral sealing material corresponding to the flat outer peripheral sealing material can be absorbed, productivity is improved.

The fuel cell of the fifteenth configuration is the same as that of the fuel cell of the fourteenth configuration, wherein the outer surface of the reaction surface outer peripheral seal member (for example, the outer peripheral seal material 52 in the embodiment) extends over the entire surface. The insulating member 271) in the embodiment is covered.
According to this configuration, the exposed metal portion of the separator on the outer part of the reaction surface outer peripheral seal member is entirely covered with the insulating member, thereby improving the corrosion resistance and preventing an electrical short circuit between adjacent separators. it can.
Therefore, the corrosion resistance of the separator can be improved, and an electrical short circuit between adjacent separators can be effectively prevented, and good power generation performance can be maintained.

The fuel cell of the sixteenth configuration is the same as the fuel cell of the fourteenth or fifteenth configuration, wherein the reaction surface outer peripheral seal member (for example, the outer peripheral seal material 52 in the embodiment) and the insulating member (for example, the embodiment). And the insulating member 271) are integrally formed.
According to this configuration, the reaction surface outer periphery sealing member and the insulating outer edge member can be simultaneously molded.
Therefore, since the reaction surface outer periphery sealing member and the insulating member can be molded simultaneously, the production cost can be reduced.

The seventeenth configuration fuel cell is the fuel cell of any one of the fourteenth to sixteenth configurations, wherein both sides of the outer portion of the reaction surface outer peripheral seal member (for example, the outer peripheral seal 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) configured integrally with the reaction surface outer periphery sealing member.
According to this configuration, the exposed metal 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 sides, so that 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 adjacent separators can be more effectively prevented, and 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, the expansion and contraction of the separator interval can be absorbed. Therefore, the foreign matter can be prevented from entering when the separator interval is increased, the sealing property is prevented from being deteriorated with the passage of time, and the seal 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 a first embodiment.
As shown in FIG. 2, the fuel cell 1 is configured by alternately laminating separators 3 and electrode membrane structures 5 formed by sandwiching a solid polymer electrolyte membrane 7 between a pair of electrodes 9. A fuel cell stack is configured by stacking a plurality of sets of batteries 1.

  As shown in FIG. 1, the separator 3 is a wave formed by press-forming a stainless steel plate having a thickness of 0.2 to 0.5 mm to form a large number of concave portions 31 having a constant height at a constant pitch. The plate portion 33 and the flat portion 35 that is in contact with each other via a sealing material at the end located outside the corrugated plate portions 33 are provided.

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

  Further, the separator 3 has an outlet side oxidant gas communication hole 41b for allowing an oxidant gas to pass therethrough and a fuel gas to the lower side of both ends in the horizontal direction located in the outer peripheral edge portion within the plane. The outlet side fuel gas communication hole 42b is provided so as to be diagonal to the inlet side oxidant gas communication hole 41a and the inlet side fuel gas communication hole 42a.

In the cathode-side separator 3 shown in FIG. 1, the oxidant gas flows from the inlet-side oxidant gas communication hole 41 a, and then flows into the concave portions 31 of the corrugated plate portion 33, and is on the short side of the separator 3. It flows from the outlet side oxidant gas communication hole 41b toward the other short side (left side in FIG. 1) from the right side (in FIG. 1).
Similarly, in the separator on the anode side (illustration of the plan view omitted), the fuel gas flows from the inlet-side fuel gas communication hole 42a, and then flows into the respective concave portions of the corrugated plate portion, so that one short side of the separator. From the side to the other short side, it flows out from the outlet side fuel gas communication hole 42b.

  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, the outlet side fuel gas communication hole 42b, and the outlet side described above. 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, outside of the corrugated plate portion 33, the inlet side oxidant gas communication hole 41 a, the outlet side oxidant gas communication hole 41 b, the inlet side fuel gas communication hole 42 a, and the outlet side fuel gas communication hole 42 b. A first sealing material 51 is disposed so as to surround the outer side 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 periphery sealing member according to the present invention.
In addition, the part adjacent to the inlet side oxidant gas communication hole 41a and the outlet side oxidant gas communication hole 41b of the outer peripheral seal material 52 cuts a seal portion to allow the oxidant gas to flow in or out. Similarly, in the separator on the anode side (illustration of the plan view is omitted), the seal portion in the portion adjacent to the inlet side fuel gas communication hole 42a and the outlet side fuel gas communication hole 42b of the outer peripheral seal material 52 is cut. Yes.

Furthermore, an insulating frame-like member 61 that covers the outer peripheral surface and the outer peripheral end surface over the entire periphery is disposed on the outer edge 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. It is comprised from the expansion-contraction absorption part 61b of the trapezoid cross section which consists of.

  The boundary surface 61A between the main body portion 61a and the expansion / contraction absorption portion 61b and the upper end surface 61bA of the expansion / contraction absorption portion 61b are set at lower positions than the upper end surfaces 51A and 53A of the first and second sealing 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 sealing materials 51, 53.

  The compression allowance refers to a crush allowance when a predetermined seal surface pressure is applied to the separator 3 by crushing the first and second seal members 51 and 53 during stacking of the separators.

  And if the recessed part 31 in the separator 3 which comprises one fuel cell 1 and the recessed part 31 in the separator 3 which comprises the other fuel cell 1 are faced | matched one by one, it will form between the recessed part 31 of the separator 3 and the electrode 9. The trapezoidal cross-section space shown in FIG. 1 becomes an oxidant gas flow path 71 for circulating the oxidant gas and a fuel gas flow path 73 for flowing the fuel gas, and is surrounded by the separator 3. The space having the hexagonal cross section becomes a cooling medium flow path 75 for circulating the cooling medium.

When the separators are stacked, 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 and contraction absorbing portion 61b of the frame-like member 61 disposed on the outer edge portion of each separator 3 is also pressed by the separator 3 to have a predetermined size, specifically, the first and second sealing materials 51 and 53. Is compressed by an amount obtained by subtracting the difference in height between the upper end surface 61bA and the upper end surfaces 51A, 53A from the compression allowance.

For this reason, even if the separator interval increases due to the influence of heat or the like, the expansion / contraction absorption part 61b of the frame-like member 61 expands by elastic return in the separator stacking direction and is separated from the expansion / contraction absorption part 61b. The main body 61a of the frame member 61 is followed.
Therefore, even if the separator interval is widened, the frame-shaped members 61 that are in contact with each other are not separated, so that foreign matter can be effectively prevented from entering from the outside, and the durability of the first and second sealing materials 51 and 53 is also improved. improves.

Moreover, since the expansion / contraction absorption part 61b can be elastically shrunk in the separator stacking direction, the relative approach of the separator 3 is not restricted as long as it can be elastically shrunk.
Therefore, even if the first and second sealing materials 51 and 53 or the electrode film structure 5 are deteriorated with time and become low in height, the stretchable absorption part 61b can contract in the separator stacking direction to reduce the separator interval. Therefore, the sealing material 51, 53 and the electrode film structure 3 and the separator 3 can be kept in close contact with each other, and the power generation performance is not deteriorated or the power generation is not disabled.

  In addition, since the frame-shaped member 61 is made of an insulating material, even if the surface of the fuel cell stack is wet due to water exposure, condensation, etc., an effect that no short circuit occurs and a short circuit due to contact between adjacent separators occur. Of course, the effect of not being able to be obtained is obtained. Furthermore, since the outer peripheral end surface of the separator 3 is covered with an insulating material, an electrical short circuit at the outer peripheral end surface of the adjacent separator 3 can be prevented.

Further, since the frame-like member 61 disposed on the entire outer periphery of the separator 3, in particular, the main body 61 a made of a hard resin material functions as a reinforcing rib, deformation of the thin metal separator 3 is also effective. 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-like member 61 may be entirely made of a soft material.

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

The frame-shaped member 81 according to this modification is configured such that the expansion / contraction absorption part 81b covers the main body part 81a, and a hole 83 is formed in at least one of the expansion / contraction absorption part 81b1 extending in parallel with the separator 3.
The main body 81a and the expansion / contraction absorption part 81b are made of, for example, the same material as the main body 61a and the expansion / contraction absorption part 61b of FIG.

  The vent hole 83 discharges excess gas or generated condensed water between the separators 3, and the positions of the openings 83 a and 83 b as shown in FIG. 3B in order to prevent foreign matter from entering from the outside. Is bent in the separator width direction (vertical direction in FIG. 3B) to be bent in a substantially Z shape.

Also according to this modification, since the frame-shaped member 81 includes the expansion / contraction absorbing portion 81b, as in the first embodiment, prevention of foreign matter intrusion when the separator interval increases, deterioration of sealing performance due to deterioration with time of the sealing material, etc. Prevention can be achieved.
Note that the frame-shaped member 81 may be connected to the second sealing material 53 like the one disposed in 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 convex portion 52a.
Hereinafter, in the description of this modification, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG.

  In the frame-shaped member 261 according to the present modified example, the expansion / contraction absorbing portion 261b (insulating outer edge member) covers the main body portion 261a, and both the outer side surfaces of the outer peripheral sealing material 52 of the separator 3, that is, the front and back surfaces of the outer portion are all over. And is covered by the stretchable absorption part 261b. Here, the outer peripheral end surface of the separator 3 is covered with a frame-like member 261, and the inner peripheral end surfaces of the communication holes 41a, 42a, 43a, 41b, 42b, 43b are covered with an expansion / contraction absorbing portion 261b.

The main body 261a and the expansion / contraction absorption part 261b are made of the same material as the main body 61a and the expansion / contraction absorption part 61b of FIG. 2, for example.
The expansion / contraction absorbing portion 261b is configured integrally with the first sealing material 51 including the outer peripheral sealing material 52, and is also configured integrally with the second sealing material 53.
And one outer peripheral sealing material flat part 52b of the adjacent separator 3 is formed in a flat shape, and the other outer peripheral sealing material convex part 52a is formed in a convex shape. Furthermore, the top of the outer peripheral sealing material convex portion 52a is formed in a cross-sectional R shape.

Also according to this modification, the expansion / contraction absorption part 261b can be elastically contracted in the separator stacking direction, so that, as in the first embodiment, the foreign matter intrusion prevention when the separator interval is increased, and the sealing performance due to the aging deterioration of the sealing material, etc. Deterioration can be prevented.
Further, 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 with the frame-like member 261 and the expansion / contraction absorbing portion 261b, the outer peripheral end surface of the adjacent separator 3 And the electrical short circuit in the inner peripheral end surface of each communicating hole 41a, 42a, 43a, 41b, 42b, 43b can be prevented.

Moreover, since all the metal exposed parts of the separator 3 in the outer part of the outer periphery sealing material 52 are covered with the expansion / contraction absorption part 261b, corrosion resistance is improved and an electrical short circuit between the adjacent separators 3 is prevented. Can do.
Moreover, since the expansion-contraction absorption part 261b, the 1st sealing material 51, and the 2nd sealing material 53 are comprised integrally, these can be shape | molded simultaneously and production cost can be reduced.

In addition, since the combination of the outer peripheral seal materials 52 is set to have a flat shape on one side and a convex shape on the other side, the relative position shift of the outer peripheral seal material convex portions 52a corresponding to the outer peripheral seal material flat portions 52b can be reduced. Therefore, productivity is improved because adjustment work for the seal position is unnecessary.
Moreover, since the center part of the cross-sectional R shape of the top part of the other outer periphery sealing material convex part 52a is strongly pressed to one outer peripheral sealing material flat part 52b at the time of separator lamination | stacking, a 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 this modification, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG.

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

Also according to this modification, since the frame-shaped member 91 includes the expansion / contraction absorbing portion 91b, as in the first embodiment, foreign matter intrusion prevention when the separator interval is increased, and sealing performance is deteriorated due to aging deterioration of the sealing material and the like. Prevention can be achieved.
Furthermore, the expansion / contraction absorption part 91b of the frame-shaped member 91 according to the present modification has a higher protrusion height from the separator 3 than the expansion / contraction absorption part 61b of the first embodiment, so that more expansion allowance can be taken. In particular, the followability when the separator interval is increased is excellent.

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

  The frame-like member 101 according to the present embodiment is different in basic configuration from the first embodiment and its modification example that absorbs expansion and contraction using elastic deformation in that it mechanically absorbs expansion and contraction in the separator stacking direction.

The frame-shaped member 101 has a convex cross-sectional shape in which a protrusion 101a protrudes from a base 101b, and the protrusion 101a is inside the fuel cell stack (right side in FIG. 5) along the separator stacking direction. And the outer side (left side in FIG. 5) are alternately arranged.
Further, the two adjacent frame-shaped members 101 are usually not in contact with the surface 101B parallel to the separator 3, but are in contact with the surface 101A parallel to the separator stacking direction.

That is, the separator interval is defined by the protruding height of the first and second sealing materials 51 and 53 (only the second sealing material 53 is shown in FIG. 5) from the separator 3, and the protruding height is The height of the protrusion 101a protruding from the separator 3 is set larger than the sum of the protrusions of the base 101b.
As a result, a gap 103 is formed between the base 101 b of one adjacent frame-like member 101 and the protrusion 101 a of the other frame-like member 101.

According to this configuration, the movement in which the separator interval expands and contracts is performed while the surface 101A of one adjacent frame-shaped member 101 and the surface 101A of the other frame-shaped member 101 slide relative to each other without being separated from each other. It is absorbed only by widening and narrowing the gap 103 between the shaped members 101.
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 performance accompanying deterioration with time of the sealing material or the like.

Furthermore, in the present embodiment, if attention is paid to two adjacent frame-shaped members 101, the surfaces 101B parallel to the separator 3 do not contact each other, and therefore, between these two frame-shaped members 101, the separator stacking direction is met. No load is generated.
Therefore, the compressive load acting on the first and second sealing members 51 and 53 is not dispersed in the frame-like member 101, and the reduction of the seal surface pressure can be effectively prevented.

FIG. 6 is a cross-sectional view showing a modification of the second embodiment.
Hereinafter, in the description of this modification, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG.

  Similarly to the configuration of FIG. 5, the frame-shaped member 111 according to this modification also performs relative sliding without causing the surface 111 </ b> A of the adjacent one of the frame-shaped members 111 and the surface 111 </ b> A of the other frame-shaped member 111 to be separated from each other. However, since the gap 113 between the frame-shaped members 111 becomes wider and narrower, as in the second embodiment, foreign matter intrusion when the separator interval is increased, sealing performance deterioration due to deterioration with time of the sealing material, etc., and sealing surface are prevented. It is possible to prevent the pressure from decreasing.

Furthermore, in this modification, the frame-shaped member 101 having the same cross-sectional shape is disposed on the outer edge portion of each separator 3 in that the frame-shaped member 111 having the same cross-sectional shape is disposed in the same form on the outer edge portion of each separator 3. Is different from the second embodiment in which the protruding direction of the protrusion 101a is alternately changed in the separator stacking direction.
Therefore, when the frame-shaped member 111 is integrally formed on the outer edge portion of the separator 3 by injection molding, it can be molded with only one type of mold, and the production cost can be reduced.

FIG. 7 is a cross-sectional view showing another modification of the second embodiment.
Hereinafter, in the description of this modification, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG.

  In the frame-shaped member 121 according to this 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 side end face.

  According to this configuration, expansion and contraction can be absorbed by widening and narrowing the gap 127 between the frame-shaped members 121 while the concave inner surface 123A parallel to the separator stacking direction and the convex outer surface 125B slide relative to each other without being separated. In addition, since the frame-shaped member 121 having the same cross-sectional shape is arranged in the same form on the outer edge portion of each separator 3, as in the modified example of FIG. It is possible to prevent the deterioration of the sealing performance due to deterioration with time, prevent the reduction of the sealing surface pressure, and reduce the production cost.

Furthermore, according to the frame-shaped member 121 according to this modification, the convex portion of the frame-shaped member 121 disposed in the other separator 3 is formed in the concave portion 123 of the frame-shaped member 121 disposed in the one adjacent separator 3. If 125 is fitted, the relative position between the separators 3 is automatically aligned, so that the workability during assembly and maintenance is improved.
That is, in the present modification, the concave portion 123 and the convex portion 125 constitute the separator positioning means 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 cross-sectional view of the main part of the fuel cell.
Hereinafter, in the description of this embodiment, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG.

In the frame-like 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 (lower right in the cross section of the main part of 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-shaped members 131 and the end surface 131B of the other frame-shaped member 131 slide relative to each other without being separated, thereby absorbing the expansion and contraction of the separator interval. 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 on the outer edge portions of the separators 3, so that the same as in the modification of FIG. Prevents foreign matter from entering when the separator spacing increases, prevents deterioration of sealing performance due to deterioration of the sealing material, etc., prevents reduction in seal surface pressure, reduces production costs, and improves 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 cross-sectional view of the main part of the fuel cell.
Hereinafter, in the description of this embodiment, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG.

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

  According to this configuration, the frame-shaped member 141 elastically expands and contracts, so that the expansion and contraction of the separator interval is absorbed, and the cross-sectional triangular groove portion 143 of the frame-shaped member 141 disposed in one adjacent separator 3 When the triangular protrusions 145 of the cross-section of the frame-shaped member 141 disposed on the separator 3 are fitted, the relative positions between the separators 3 are automatically aligned, and furthermore, the same cross-sectional shape is formed on the outer edge of each separator 3. Since the frame-shaped members are arranged in the same form, in the same way as in the configuration of FIG. 8, the prevention of foreign matter intrusion when the separator interval is increased, the deterioration of the sealing performance with the aging of the sealing material, etc., and the sealing surface pressure It is possible to prevent reduction, reduce production costs, and improve workability during assembly and maintenance.

In the configuration in which the frame-shaped members 61, 81, 91, 101, 111, 121, 131, 141 described above are provided on the separator outer edge portion, the outer edge of the separator 3 is bent 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 frame members 61, 81, 91, 101, 111, 121, 131, and 141. The deformation of the separator 3 and the 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 invention will be described.
FIG. 11 is a cross-sectional view of the main part of the fuel cell.
Hereinafter, in the description of this embodiment, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG.

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 are provided. 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 disposed around the hole 42b and the outlet side cooling medium communication hole 43b.
In FIG. 11, only the outlet side fuel gas communication hole 42b is shown.

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, the fuel cell according to the present embodiment has a disadvantageous structure for preventing the electrical short circuit between the separators due to the short distance between the separators because the metal thin separator 3 is used. The effect is exceptional.
In addition, 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.

  Further, the protruding height of the insulating member from the front and back surfaces of the separator is such that the insulating member 201 disposed on one adjacent separator 3 and the other insulating member 201 are not in contact with each other, that is, insulative. Since the gap 203 is set to be formed between the members 201, the gap 203 is widened and narrowed to absorb the expansion and contraction of the separator interval.

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 with time of the sealing material, and to prevent reduction of the seal surface pressure.
Furthermore, since the insulating member 201 having the same cross-sectional shape is arranged in the same form around the communication hole of each separator 3, when the insulating member 201 is integrally formed with the separator 3 by injection molding, one kind of gold is used. Molding is possible with just the mold, and production costs can be reduced.

FIG.12 and FIG.13 is sectional drawing which shows the modification of 5th Embodiment.
Hereinafter, in the description of this modification, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG.

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

According to these configurations, similar to the configuration of FIG. 11, the liquid junction in the cooling medium flow path and the electrical short circuit prevention between adjacent separators in the reaction gas flow path, the prevention of foreign matter intrusion when the separator interval increases, the sealing material Thus, it is possible to prevent deterioration of the sealing performance due to deterioration over time and the like, and to prevent reduction of the seal surface pressure.
In particular, in the modified example of FIG. 13, the insulating members 221 arranged around the communication holes 41a, 42a, 43a, 41b, 42b, and 43b all have the same cross-sectional shape. When the member 221 is integrally formed with the separator, it can be formed with only one type of mold, and the production cost can be reduced.

14 and 15 are cross-sectional views showing still another modification of the fifth embodiment.
Hereinafter, in the description of this modification, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG.

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

  Also with these configurations, similar to the configuration of FIG. 11, the liquid junction in the cooling medium flow path and the electrical short circuit prevention between adjacent separators in the reaction gas flow path, the prevention of foreign matter intrusion when the separator interval increases, the sealing material, etc. It is possible to prevent the deterioration of the sealing performance accompanying the deterioration with time, the reduction of the sealing surface pressure, and 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 the main part of the fuel cell, and FIG. 19B is an enlarged view of the outer peripheral sealing material convex portion 52a.
Hereinafter, in the description of this modification, 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 part of the outer peripheral sealing material 52 of the separator 3, that is, the front and back of the outer part are covered with the insulating member 271 over the entire surface. Further, the outer peripheral end surface of the separator 3 and the inner peripheral end surfaces of the communication holes 41 a, 42 a, 43 a, 41 b, 42 b, 43 b are also covered with an insulating member 271.
The insulating member 271 is made of a soft and elastic material such as rubber, for example, like the expansion / contraction absorbing portion 61b of FIG.

Further, the insulating member 271 is configured integrally with the first sealing material 51 including the outer peripheral sealing material 52, and is also configured integrally with the second sealing material 53.
And one outer peripheral sealing material flat part 52b (insulating member flat part 271b) of the adjacent separator 3 is formed in a flat shape, and the other outer peripheral sealing material convex part 52a (insulating member convex part 271a) is convex. Is formed. Furthermore, the top of the outer peripheral sealing material convex portion 52a is formed in a cross-sectional R shape.
A stepped portion 3d is formed on the outer peripheral portion of the separator 3 and the inner peripheral portions of the communication holes 41a, 42a, 43a, 41b, 42b, 43b, and the stepped portion 3d allows the outer peripheral portion of the separator 3 and each communication hole to be formed. The inner peripheral portions of 41a, 42a, 43a, 41b, 42b, and 43b are changed to the reaction surface 3A side of the separator 3. A gap 273 is formed between the reaction surfaces 3 </ b> A of the adjacent separators 3.

According to this structure, the electrical short circuit in the outer peripheral end surface of the adjacent separator 3 and the inner peripheral end surface of each communicating hole 41a, 42a, 43a, 41b, 42b, 43b can be prevented effectively.
In addition, since the metal exposed portions of the separator 3 on both sides of the outer peripheral sealing material 52 are all covered with the insulating member 271, 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 molded at the same time, and the production cost can be reduced.

Further, since the combination of the outer peripheral sealing materials 52 is formed in a flat shape on one side and a convex shape on the other side, the relative position shift of the outer peripheral sealing material convex portion 52a corresponding to the outer peripheral sealing material flat portion 52b is reduced. Therefore, productivity is improved because adjustment work for the seal position is unnecessary.
Moreover, since the center part of the cross-sectional R shape of the top part of the other outer periphery sealing material convex part 52a is strongly pressed to one outer peripheral sealing material flat part 52b at the time of separator lamination | stacking, a sealing performance can be improved.

Further, since the step portion 3d functions as a reinforcing rib around the outer edge portion and the communication hole of the thin metal separator 3, the deformation can be effectively prevented.
Further, the height of the stepped portion protruding 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 and narrowing, it is also possible to absorb the expansion and contraction 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 with time of the sealing material, and to prevent reduction of the seal surface pressure.

FIG. 16 is a cross-sectional view showing the sixth embodiment.
Hereinafter, in the description of this embodiment, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG.

  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 an elastic absorption part 251b made of a vibration-proof material such as rubber, and the elastic absorption part 251b is attached to the vehicle main body. This is also used as a mounting part.

Also with this configuration, as in the configuration of FIG. 2, it is possible to prevent foreign matter from entering when the separator interval is increased, and to prevent deterioration in sealing performance due to deterioration over time of the sealing material or the like.
Furthermore, when the fuel cell 1 is stacked in the horizontal direction (horizontal direction) and placed on the attachment surface 300, the vibration absorbing function is achieved by the expansion / contraction absorbing portion 251 b of the frame-like member 251 being in contact with the attachment surface 300 of the fuel cell 1. Therefore, it is not necessary to separately attach a vibration isolation 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 a plurality of fuel cells.
The modification shown in FIG. 17 shows a fuel cell stack in which an expansion / contraction absorption part 251b made of an anti-vibration material is provided for each fuel cell. In this fuel cell stack, the expansion / contraction absorption part 251b made of an anti-vibration material and 2, the stretch absorbing portions 251 c made of the same material as the stretch absorbing portions 61 b of FIG. 2 are alternately arranged every other separator 3.

  In addition, in the above embodiment and modification, although the separator 3 is comprised from stainless steel, you may comprise from other metal materials and carbonaceous materials, such as titanium.

1 is a plan view showing a separator of a solid 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 the line AA in FIG. 1. (A) is principal part sectional drawing which shows the modification of 1st Embodiment, (b) is BB sectional drawing of (a). It is principal part sectional drawing which shows the further another modification of 1st Embodiment. It is principal part sectional drawing which shows the 2nd Embodiment of this invention. It is principal part sectional drawing which shows the modification of 2nd Embodiment. It is principal part sectional drawing which shows the other modification of 2nd Embodiment. It is principal part sectional drawing which shows the 3rd Embodiment of this invention. It is principal part sectional drawing which shows the modification of 3rd Embodiment. It is principal part sectional drawing which shows the other modification of 3rd Embodiment. It is principal part sectional drawing which shows the 4th Embodiment of this invention. It is principal part sectional drawing which shows the modification of 4th Embodiment. It is principal part sectional drawing which shows the other modification of 4th Embodiment. It is principal part sectional drawing which shows the 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 the 6th Embodiment of this invention. It is principal part sectional drawing which shows the modification of 6th Embodiment. (A) is principal part sectional drawing which shows the other modification of 1st Embodiment, (b) is an enlarged view of an outer peripheral sealing material convex part. (A) is principal part sectional drawing which shows 5th Embodiment, (b) is an enlarged view of an outer peripheral sealing material convex part.

Explanation of symbols

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 sealing material (reactive surface outer peripheral sealing member)
52a Peripheral sealing material convex part (convex shape))
52b Peripheral seal material flat part (flat shape)
61, 81, 91, 101, 111, 121, 131, 141, 251, 261 Frame-shaped member 61a, 81a, 91a, 261a Main body (part made of hard material)
61b, 81b, 91b, 261b (insulating outer edge member) Stretch / absorption part (part composed of soft material)
123 Concavity (part of positioning means)
125 Convex (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 Insulating member flat part (flat shape)

Claims (6)

A pair of electrodes on both sides of the solid polymer electrolyte membrane, a fuel cell formed by sandwiching the outer pair of sheet metal separator, around the communication holes ambient formed in the separator is sealed, the communicating A fuel cell comprising an insulating member that covers an inner peripheral end face of a hole so as to sandwich the hole . Between each insulating member of said separator adjacent fuel cell according to claim 1, characterized in that a gap is formed in the stacking direction of the separators. 2. The fuel cell according to claim 1, wherein insulating members around the communication hole are in contact with each other between the adjacent separators. The fuel cell according to claim 3, wherein the insulating member around the communication hole is configured to be relatively slidable between the adjacent separators. 4. The fuel cell according to claim 3, wherein between the adjacent separators, one of the insulating members around the communication hole is convex and the other is flat. 5. The fuel cell according to claim 1, wherein a step is provided around the communication hole of the separator.

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