Fuel cell stack and detection terminal for fuel cell stack

Abstract

To provide a fuel cell stack to which a detection terminal can be easily attached, and a detection terminal for the fuel cell stack.SOLUTION: When facing surfaces of a cathode side separator 50 and an anode side separator 30 are defined as a first facing surface 50b and a second facing surface 30b respectively, first engaging portions 40a and 40b are provided on the first facing surface 50b. A detection terminal 60 includes a base portion 70 that abuts on the first facing surface 50b, and an arm portion 80 that protrudes from the base portion 70 toward the second facing surface 30b and extends toward the rear side in the insertion direction of the detection terminal 60. The detection terminal 60 further includes second engaging portions 81A and 81B that are engaged with the first engaging portions 40a and 40b in an uneven relationship to prevent the detection terminal 60 from coming off from a stack body. The arm portion 80 is in contact with the second facing surface 30b while being elastically deformed toward the first facing surface 50b.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a fuel cell stack and a detection terminal for a fuel cell stack. [Background technology]

[0002] Patent Document 1 discloses a fuel cell module having a stack formed by stacking multiple cells and a connector attached to each cell. The connector measures the cell voltage. The cell includes a first separator, a second separator, an insulating frame, and a membrane electrode assembly. The membrane electrode assembly (hereinafter referred to as a power generation section) is sandwiched between the first separator and the second separator. An insulating frame is provided between the first separator and the second separator, surrounding the power generation section. An attachment section to which a connector is attached is formed on the edge of the first separator. The connector is provided with a pair of protrusions that sandwich the attachment section from both sides in the thickness direction of the first separator.

[0003] When attaching the connector, the worker inserts the attachment portion of the first separator between the tip ends of the pair of protrusions, and then pushes the connector into a predetermined position. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-9004 Summary of the Invention [Problem to be solved by the invention]

[0005] In the case of the connector disclosed in Patent Document 1, the worker needs to check that the tip portions of the pair of protrusions are sandwiching the mounting portion of the first separator, which makes the mounting work complicated.

[0006] An object of the present invention is to provide a fuel cell stack and a detection terminal for a fuel cell stack to which a detection terminal can be easily attached. [Means for solving the problem]

[0007] A fuel cell stack for solving the above problem is a fuel cell stack comprising a stack body formed by stacking a plurality of unit cells each having a power generation section, a first separator, and a second separator, the unit of which is sandwiched between the first separator and the second separator, the stack body comprising a metal detection terminal inserted from the outer periphery of the unit cell between the first separator constituting the unit and the second separator of another unit cell adjacent to the unit cell, the metal detection terminal being inserted from the outer periphery of the unit cell, when the opposing surfaces of the first separator and the second separator are defined as a first opposing surface and a second opposing surface, respectively, the first opposing surface is provided with a first engagement portion, the detection terminal has a base portion abutting the first opposing surface, an arm portion protruding from the base portion towards the second opposing surface and extending rearward in the insertion direction of the detection terminal, and a second engagement portion that engages with the first engagement portion in a concave-convex relationship to prevent the detection terminal from coming out of the stack body, the arm portion abutting the second opposing surface while being elastically deformed towards the first opposing surface.

[0008] According to this configuration, when the detection terminal is inserted between the first separator and the second separator from the outer periphery of the unit cell, the arm portion elastically deforms toward the first opposing surface, causing the base portion to abut against the first opposing surface and the arm portion to abut against the second opposing surface. The second engagement portion of the detection terminal then engages with the first engagement portion provided on the first opposing surface in a convex-concave relationship. Here, the base portion and the arm portion are biased against the first opposing surface and the second opposing surface, respectively, maintaining the engagement between the second engagement portion and the first engagement portion. This prevents the detection terminal from slipping out of the stack body. In this way, the detection terminal can be easily attached between the first separator constituting a unit cell and the second separator of another unit cell adjacent to the unit cell by a simple attachment method in which the detection terminal is inserted from the outer periphery of the unit cell.

[0009] Furthermore, a detection terminal for a fuel cell stack for solving the above problem is applied to a fuel cell stack having a stack body formed by stacking a plurality of unit cells each having a power generation unit, a first separator, and a second separator, with the power generation unit sandwiched between the first separator and the second separator, and is a metal detection terminal inserted from the outer periphery of the unit cell between the first separator constituting the unit and the second separator of another unit cell adjacent to the unit cell, and when the opposing surfaces of the first separator and the second separator are defined as a first opposing surface and a second opposing surface, respectively, the detection terminal has a base portion abutting the first opposing surface, an arm portion protruding from the base portion toward the second opposing surface and extending toward the rear in the insertion direction of the detection terminal, and an engaging portion that engages in a concave-convex relationship with an engaged portion provided on the first opposing surface to prevent the detection terminal from coming out of the stack body, and the arm portion abuts the second opposing surface while being elastically deformed toward the first opposing surface. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is an exploded perspective view of an embodiment of a fuel cell stack, showing a unit cell and a detection terminal spaced apart from each other. [Figure 2] FIG. 2 is an exploded perspective view of the unit cell of FIG. [Figure 3] FIG. 3 is a perspective view showing the detection terminal of FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line 6-6 in FIG. [Figure 7] 7(a) to 7(d) are cross-sectional views showing the procedure for attaching and detaching the detection terminal. [Figure 8] FIG. 8 is a view corresponding to FIG. 5 and is a cross-sectional view showing the attachment state of the detection terminal of the first modified example. [Figure 9] FIG. 9 is a cross-sectional view taken along line 9-9 in FIG. [Figure 10] FIG. 10 is a view corresponding to FIG. 5 and is a cross-sectional view showing the attachment state of the detection terminal of the second modified example. [Figure 11] FIG. 11 is a cross-sectional view taken along the line AA in FIG. [Figure 12] FIG. 12 is a view corresponding to FIG. 5 and is a cross-sectional view showing the attachment state of the detection terminal of the third modified example. [Figure 13] FIG. 13 is a cross-sectional view taken along line BB in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of a fuel cell stack and a detection terminal for a fuel cell stack will be described below with reference to FIGS. In each drawing, for the sake of convenience, some components are shown exaggerated or simplified, and the dimensional proportions of each component may differ from the actual proportions.

[0012] As shown in FIG. 1, the fuel cell stack includes a stack body 10 formed by stacking a plurality of unit cells 90, and a detection terminal 60 made of metal. First, the unit cell 90 will be described.

[0013] <Single cell 90> As shown in FIG. 2, the single cell 90 includes a membrane electrode assembly 11 (MEA, hereinafter referred to as the power generation section 11), an electrically insulating sheet member 20 surrounding the power generation section 11, and a cathode-side separator 50 and an anode-side separator 30 sandwiching the power generation section 11 and the sheet member 20 therebetween.

[0014] The unit cell 90 has a rectangular plate shape as a whole. In the following description, the stacking direction of the anode separator 30, the power generating section 11, the sheet member 20, and the cathode separator 50, and the stacking direction of the plurality of unit cells 90 will be referred to as a first direction X.

[0015] The directions in which the long sides of the unit cell 90 extend and the short sides of the unit cell 90 extend are respectively referred to as the second direction Y and the third direction Z. The first direction X, the second direction Y, and the third direction Z form an orthogonal coordinate system.

[0016] The unit cell 90 has inlet holes 91, 93, and 95 for introducing fuel gas, cooling medium, and oxidizer gas into the unit cell 90, respectively, and outlet holes 92, 94, and 96 for discharging the fuel gas, cooling medium, and oxidizer gas from the unit cell 90 to the outside, respectively.

[0017] The inlet holes 91, 93, 95 and the outlet holes 92, 94, 96 penetrate the unit cell 90 in the first direction X. The inlet hole 91 and the outlet holes 94, 96 are provided on one side of the unit cell 90 in the second direction Y (the left side in the left-right direction in FIG. 1). The inlet hole 91 and the outlet holes 94, 96 are lined up in sequence at intervals from each other in the third direction Z. The outlet hole 92 and the inlet holes 93, 95 are provided on the other side of the unit cell 90 in the second direction Y (the right side in FIG. 1). The outlet hole 92 and the inlet holes 93, 95 are lined up in sequence at intervals from each other in the third direction Z.

[0018] <Power Generation Section 11> 2, the power generation unit 11 has a solid polymer electrolyte membrane (hereinafter referred to as the electrolyte membrane) (not shown) and electrodes 11A and 11B provided on both sides of the electrolyte membrane. In this embodiment, the electrode bonded to one side (the upper side in the vertical direction in FIG. 1) of the electrolyte membrane (not shown) in the first direction X is the cathode electrode 11A. The electrode bonded to the other side (the lower side in FIG. 1) of the electrolyte membrane in the first direction X is the anode electrode 11B.

[0019] The electrodes 11A and 11B each have a catalyst layer (not shown) bonded to the electrolyte membrane, and a gas diffusion layer 12 (hereinafter, GDL 12) bonded to the catalyst layer. <Sheet member 20> 2, the sheet member 20 is provided between the cathode-side separator 50 and the anode-side separator 30 that constitute the unit cell 90. The sheet member 20 has a generally rectangular plate shape in plan view that is elongated in the second direction Y. The sheet member 20 is formed, for example, from an electrically insulating synthetic resin material.

[0020] The sheet member 20 has through holes 21, 22, 23, 24, 25, and 26 which constitute the holes 91, 92, 93, 94, 95, and 96, respectively. The sheet member 20 has an opening 27 in the center. The inner periphery of the opening 27 is joined to the periphery of the power generation section 11 from one side in the first direction X (the upper side in FIG. 1).

[0021] <Cathode-side separator 50> As shown in FIG. 2, the cathode separator 50 has a rectangular plate shape that is long in the second direction Y when viewed from above.

[0022] The cathode separator 50 is formed by press-forming a thin metal plate made of, for example, titanium, stainless steel, or the like. The cathode separator 50 is provided on the cathode electrode 11A side of the power generating section 11.

[0023] The cathode separator 50 has a sandwiching surface 50a that faces the power generation section 11, and a first opposing surface 50b that is the surface opposite to the sandwiching surface 50a and faces the anode separator 30 of another adjacent unit cell 90.

[0024] The cathode separator 50 has through holes 51, 52, 53, 54, 55, and 56 which constitute the holes 91, 92, 93, 94, 95, and 96, respectively. As shown in Fig. 2, the cathode separator 50 has a plurality of groove channels 57 through which an oxidant gas flows and a plurality of groove channels 58 through which a coolant flows. The groove channels 57 are provided on the sandwiching surface 50a. The groove channels 58 are provided on the first opposing surface 50b. Note that Fig. 2 shows a simplified view of the outer edge of the portion of the cathode separator 50 where the plurality of groove channels 57 are formed and the outer edge of the portion of the cathode separator 50 where the plurality of groove channels 58 are formed.

[0025] 2 and 5, a plurality of first engagement portions 40a, 40b are provided on the first opposing surface 50b. The first engagement portions 40a, 40b are provided, for example, between the through hole 51 and the through hole 55 in the second direction Y. In this embodiment, the first engagement portions 40a, 40b are provided at positions closer to the through hole 55 than the through hole 51 in the second direction Y.

[0026] The first engagement portions 40a, 40b protrude in the first direction X toward the second opposing surface 30b of another unit cell 90 adjacent to the unit cell 90 on which the first engagement portions 40a, 40b are provided.

[0027] In this embodiment, the first engagement portions 40a and 40b are frustoconical. The first engagement portions 40a, 40b are provided at an interval from each other in the third direction Z.

[0028] The cathode separator 50 corresponds to the first separator according to the present invention. <Anode-side separator 30> As shown in FIG. 2, the anode separator 30 has a rectangular plate shape that is long in the second direction Y when viewed from above.

[0029] The anode-side separator 30 is formed by press-forming a thin metal plate made of, for example, titanium, stainless steel, or the like. The anode separator 30 is provided on the anode electrode 11B side of the power generating section 11.

[0030] The anode side separator 30 has a sandwiching surface 30a that faces the power generation section 11, and a second opposing surface 30b that is the surface opposite to the sandwiching surface 30a and faces the cathode side separator 50 of another adjacent unit cell 90.

[0031] The anode separator 30 has through-holes 31, 32, 33, 34, 35, and 36 that constitute the holes 91, 92, 93, 94, 95, and 96, respectively. As shown in Fig. 2, the anode-side separator 30 has a plurality of groove channels 37 through which a fuel gas flows and a plurality of groove channels 38 through which a coolant flows. The groove channels 37 are provided on the sandwiching surface 30a. The groove channels 38 are provided on the second opposing surface 30b. Note that Fig. 2 shows a simplified view of the outer edge of the portion of the anode-side separator 30 where the plurality of groove channels 37 are formed and the outer edge of the portion of the anode-side separator 30 where the plurality of groove channels 38 are formed.

[0032] The anode side separator 30 corresponds to the second separator according to the present invention. <Detection terminal 60> 1, the detection terminals 60 are provided on both sides of the unit cell 90 in the first direction X. The detection terminals 60 are formed by press-forming a metal plate material. Examples of the metal plate material that can be used include titanium, stainless steel, aluminum, and copper.

[0033] 5 and 6, the detection terminal 60 is inserted from the outer periphery of the unit cell 90 between the cathode separator 50 constituting the unit cell 90 and the anode separator 30 of another unit cell 90 adjacent to the unit cell 90. In this embodiment, the detection terminal 60 is inserted along the third direction Z.

[0034] In the following description, the front and rear sides in the insertion direction of the detection terminal 60 will be simply referred to as the front and rear sides. As shown in FIGS. 3 and 4, the detection terminal 60 has a base portion 70, an arm portion 80, and second engagement portions 81A and 81B.

[0035] The base portion 70 has a connecting portion 71 and a pair of extending portions 72. The connecting portion 71 extends in the second direction Y. The pair of extending portions 72 extend rearward from both ends of the connecting portion 71 in the second direction Y. The connecting portion 71 and the pair of extending portions 72 are both flat plate-shaped and located on the same plane along the surface direction of the single cell 90.

[0036] 5 and 6, the base portion 70 abuts against the first opposing surface 50b. The pair of extending portions 72 sandwich the pair of first engaging portions 40a, 40b in the second direction Y. The arm portion 80 protrudes from the base portion 70 toward the second opposing surface 30b and extends rearward.

[0037] The arm portion 80 is connected to the center portion of the connecting portion 71 in the second direction Y. The arm portion 80 has, in order from the front side, a first inclined portion 81a, a first flat portion 81b, a second inclined portion 81c, a second flat portion 81d, a third inclined portion 81e, a third flat portion 81f, and a protruding portion 81g.

[0038] The first inclined portion 81a is inclined so as to approach the second opposing surface 30b in the first direction X toward the rear side. The first flat portion 81b extends in the third direction Z from the rear end of the first inclined portion 81a toward the rear side.

[0039] The second inclined portion 81c is inclined so as to move away from the second opposing surface 30b in the first direction X toward the rear side. The second flat portion 81d extends in the third direction Z from the rear end of the second inclined portion 81c toward the rear side.

[0040] The third inclined portion 81e is inclined so as to approach the second opposing surface 30b in the first direction X toward the rear side. The third flat portion 81f extends in the third direction Z from the rear end of the third inclined portion 81e toward the rear side.

[0041] The second flat portion 81d, the first flat portion 81b, and the third flat portion 81f are provided in this order at positions farther away from the second opposing surface 30b in the first direction X. The protruding portion 81g protrudes from the center of the third flat portion 81f in the third direction Z toward the second opposing surface 30b.

[0042] The first inclined portion 81a, the first flat portion 81b, and the second inclined portion 81c form a second engaging portion 81A that engages with the front first engaging portion 40a in a concave-convex relationship. The third inclined portion 81e and the third flat portion 81f form a second engagement portion 81B that engages with the rear first engagement portion 40b in a concave-convex relationship.

[0043] That is, two second engagement portions 81A and 81B are provided corresponding to the two first engagement portions 40a and 40b. With the arm portion 80 elastically deformed toward the first opposing surface 50b, the protrusion 81g abuts against the second opposing surface 30b.

[0044] The detection terminal 60 has a protruding portion 65 that protrudes outward from the edge portions 50A, 30A of the cathode-side separator 50 and the anode-side separator 30. That is, the protruding portion 65 is formed by the tip portions of the pair of extending portions 72 of the base portion 70 and the tip portion of the third flat portion 81f of the arm portion 80. That is, the base portion 70 and the arm portion 80 protrude outward from the unit cell 90.

[0045] 2 and 5, the sheet member 20 has a cover portion 28 that covers the protruding portion 65 in the first direction X. The cover portion 28 protrudes from the edge of the sheet member 20 toward the outer periphery. The cover portion 28 is provided over the entire protruding portion 65 in the second direction Y. In this embodiment, the length of the cover portion 28 in the second direction Y is greater than the length of the protruding portion 65 in the second direction Y.

[0046] The protruding portion 65 is provided with a mark 66 at the position of the tip 28a of the cover portion 28 in the third direction Z, i.e., the insertion direction, which indicates that the detection terminal 60 is inserted to the correct position.

[0047] As shown in FIGS. 5 and 6, in this embodiment, the tip 28a of the cover portion 28 coincides with the tip of the protruding portion 65 of the detection terminal 60 in the first direction X. In this embodiment, the mark 66 is the tip of the protruding portion 65 .

[0048] Next, the procedure for attaching and detaching the detection terminal 60 of this embodiment will be described. 7(a), when attaching the detection terminal 60, the worker pinches the tip ends of the pair of extension portions 72 and the tip end of the third flat portion 81f of the arm portion 80 with their fingers, and presses the arm portion 80 so that these tip ends approach each other, thereby elastically deforming the arm portion 80. The worker inserts the detection terminal 60 in this state between the anode-side separator 30 and the cathode-side separator 50 with the connecting portion 71 facing forward.

[0049] Next, as shown in FIG. 7(b), the worker slides the first flat portion 81b over the second opposing surface 30b and inserts the detection terminal 60 in the first direction X until the tip of the protruding portion 65 of the detection terminal 60 coincides with the tip 28a of the cover portion 28.

[0050] Next, as shown in Figure 7(c), when the worker releases his or her finger from the detection terminal 60, the elastically deformed arm 80 returns to its original position toward the second opposing surface 30b. As a result, the base 70 abuts against the first opposing surface 50b, and the protruding portion 81g of the arm 80 abuts against the second opposing surface 30b. Furthermore, the second engagement portions 81A and 81B are engaged with the first engagement portions 40a and 40b in a concave-convex relationship. In this way, the installation of the detection terminal 60 is completed.

[0051] 7(d), when removing the detection terminal 60, the worker pinches the tip ends of the pair of extension portions 72 and the tip end of the third flat portion 81f of the arm portion 80 with their fingers and presses the arm portion 80 so that these tip ends approach each other, thereby elastically deforming the arm portion 80. Next, the worker pulls the detection terminal 60 in this state out from between the anode-side separator 30 and the cathode-side separator 50 in the reverse order of the installation procedure. This completes the removal of the detection terminal 60.

[0052] Next, the operation of this embodiment will be described. As shown in FIG. 6 , the detection terminal 60 is inserted between the cathode-side separator 50 and the anode-side separator 30 from the outer periphery of the unit cell 90. At this time, the arm 80 elastically deforms toward the first opposing surface 50b, causing the base 70 to abut against the first opposing surface 50b and the arm 80 to abut against the second opposing surface 30b. The second engagement portions 81A and 81B of the detection terminal 60 then engage with the first engagement portions 40a and 40b provided on the first opposing surface 50b in a convex-concave relationship. Here, the base 70 and the arm 80 are biased against the first opposing surface 50b and the second opposing surface 30b, respectively, maintaining the engagement between the second engagement portions 81A and 81B and the first engagement portions 40a and 40b. This prevents the detection terminal 60 from coming off the stack body 10. Therefore, the detection terminal 60 can be attached by a simple attachment method in which the detection terminal 60 is inserted from the outer periphery of the unit cell 90 between the cathode side separator 50 that constitutes the unit cell 90 and the anode side separator 30 of another unit cell 90 adjacent to the unit cell 90.

[0053] Next, the effects of this embodiment will be described. (1) The detection terminal 60 has a base portion 70 that abuts against the first opposing surface 50b, and an arm portion 80 that protrudes from the base portion 70 toward the second opposing surface 30b and extends rearward in the insertion direction of the detection terminal 60. The detection terminal 60 also has second engagement portions 81A, 81B that engage with the first engagement portions 40a, 40b in a concave-convex relationship to prevent the detection terminal 60 from slipping out of the stack main body 10. The arm portion 80 abuts against the second opposing surface 30b in a state where it is elastically deformed toward the first opposing surface 50b.

[0054] According to this configuration, the above-mentioned effect is achieved, and the detection terminal 60 can be easily attached. (2) The first engagement portions 40a and 40b protrude toward the second opposing surface 30b.

[0055] If the first engagement portions 40a, 40b are recesses that open to the first opposing surface 50b, forming the recesses by pressing a metal sheet results in the formation of protrusions on the surface of the cathode-side separator 50 that faces the sheet member 20. In this case, since the protrusions interfere with the sheet member 20, it is necessary to take measures such as providing a recess in the sheet member 20 to allow the protrusions to escape.

[0056] In this regard, according to the above configuration, the first engagement portions 40a, 40b protrude toward the second opposing surface 30b, so the above-mentioned inconvenience does not occur. (3) The first engaging portions 40a, 40b are provided in plural and spaced apart from each other in the insertion direction. The second engaging portions 81A, 81B are provided in plural corresponding to the first engaging portions 40a, 40b, respectively.

[0057] For example, if the first and second engagement portions have a circular cross section, and one first engagement portion and one second engagement portion are provided, there is a risk that the detection terminal 60 will rotate around the first engagement portion.

[0058] In this regard, according to the above configuration, since a plurality of first engagement portions 40a, 40b are provided at intervals in the insertion direction, it is possible to prevent the detection terminal 60 from rotating around the first engagement portions 40a, 40b, thereby stabilizing the mounting posture of the detection terminal 60.

[0059] (4) The base portion 70 and the arm portions 80 protrude from the unit cell 90 toward the outer periphery. With this configuration, when removing the detection terminal 60 from the stack main body 10, the worker can pinch the portions of the base portion 70 and the arm portion 80 that protrude from the unit cell 90 toward the outer periphery. Furthermore, by pinching the protruding portions of the base portion 70 and the arm portion 80 and pressing the arm portion 80 in a direction toward the base portion 70, the arm portion 80 can be elastically deformed. This makes it possible to easily release the engagement between the first engagement portions 40a, 40b and the second engagement portions 81A, 81B. The detection terminal 60 can then be easily removed from the stack main body 10 by pulling it out.

[0060] (5) An electrically insulating sheet member 20 is provided between the cathode-side separator 50 and the anode-side separator 30 that constitute the unit cell 90, surrounding the power generation section 11. A detection terminal 60 is provided on each side of the unit cell 90 in the stacking direction. The detection terminal 60 has a protruding portion 65 that protrudes outward beyond the edge portions 50A, 30A of the cathode-side separator 50 and the anode-side separator 30. The sheet member 20 has a cover portion 28 that covers the protruding portion 65 in the stacking direction.

[0061] With this configuration, the protruding portions 65 of the detection terminals 60 provided on both sides of the unit cell 90 are electrically insulated from each other by the cover portion 28 of the sheet member 20. This makes it possible to omit a dedicated insulating member for electrically insulating the protruding portions 65 from each other.

[0062] (6) The protruding portion 65 is provided with a mark 66 at the position of the tip 28a of the cover portion 28 in the insertion direction, and the mark 66 indicates that the detection terminal 60 is inserted to the correct position.

[0063] With this configuration, the worker can easily confirm that the detection terminal 60 has been inserted to the correct position by visually checking that the mark 66 on the protruding portion 65 of the detection terminal 60 is positioned at the tip 28a of the cover portion 28 in the insertion direction.

[0064] (7) The mark 66 is the tip of the protruding portion 65. According to this configuration, the tip of the protruding portion 65 of the detection terminal 60 serves as the mark 66, which simplifies the configuration of the detection terminal 60. This eliminates the need to form a separate mark on the protruding portion 65.

[0065] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0066] The protruding portion 65 of the detection terminal 60 may be configured to protrude further outward than the tip 28a of the cover portion 28. In this case, a mark may be provided on the protruding portion 65 at the position of the tip 28a of the cover portion 28 in the third direction Z.

[0067] 8 and 9, the detection terminal 160 of the first modified example differs from the first embodiment in that the second engagement portion 181 is provided on the base portion 170 and that there is only one second engagement portion 181. In this case, the second engagement portion 181 is a through-hole that penetrates the first connecting portion 171 of the base portion 170 in the first direction X. The arm portion 180 has only an inclined portion 181a and a flat portion 181b. The flat portion 181b abuts against the second opposing surface 30b. The base portion 170 also has a second connecting portion 173 that connects the tips of the pair of extending portions 172.

[0068] 10 and 11, in a detection terminal 260 of the second modified example, an arm portion 280 has only an inclined portion 281a. The inclined portion 281a abuts against the second opposing surface 30b. 12 and 13, the base portion 370 may have a circular ring portion 382 and an extension portion 383 extending rearward from the circular ring portion 382. In this case, a hole in the circular ring portion 382 constitutes the second engagement portion 381. Also, an arm portion 380 may be configured to protrude from a front portion of the circular ring portion 382.

[0069] For example, an insulating coating may be provided on the protruding portion 65 of the detection terminal 60. In this case, the cover portion 28 may be omitted. The detection terminal 60 may be provided on one side of the unit cell 90 in the first direction X.

[0070] Three or more first engagement portions may be provided. In this case, the number of second engagement portions can be changed in accordance with the number of first engagement portions. The first engagement portions 40a, 40b are not limited to those having a truncated cone shape, i.e., a circular cross-sectional shape. The first engagement portions may have, for example, a rectangular or elliptical cross-sectional shape. In this case, even if only one first engagement portion is provided, it is possible to prevent the detection terminal 60 from rotating around the first engagement portion.

[0071] The first engagement portions 40a, 40b may be recesses that open to the first opposing surface 50b. At least one of the anode separator 30 and the cathode separator 50 may be made of a resin containing carbon.

[0072] In the above embodiment and each modified example, the first engaging portions 40a, 40b are provided on the cathode-side separator 50, but the first engaging portions 40a, 40b may be provided on the anode-side separator 30. In this case, the anode-side separator 30 corresponds to the first separator, and the cathode-side separator 50 corresponds to the second separator. [Explanation of symbols]

[0073] 10...Stack body 11...Power generation section 11A...Cathode electrode 11B...Anode electrode 12...Gas diffusion layer 20...Sheet member 21...Through hole 22...Through hole 23...Through hole 24...Through hole 25...Through hole 26...Through hole 27...Opening 28...Cover part 28a...Tip 30...Anode side separator (second separator) 30A…Edge 30a...Pinching surface 30b…Second opposing surface 31...Through hole 32...Through hole 33...Through hole 34...Through hole 35...Through hole 36...Through hole 37…Groove channel 38…Groove channel 40a, 40b...first engaging part (engaged part) 50...Cathode side separator (first separator) 50A...Edge 50a...Pinching surface 50b…First facing surface 51...Through hole 52...Through hole 53...Through hole 54...Through hole 55...Through hole 56...Through hole 57…Groove channel 58...Groove channel 60, 160, 260...Detection terminal 65...Protruding part 66...Landmark 70, 170, 370...Base 71...Connection part 72,172... Extension part 80,180,280,380... Wrist part 81A,81B,181,381... Second engaging part (engaging part) 81a... First inclined part 81b... First flat part 81c... Second inclined part 81d... Second flat part 81e... Third inclined part 81f... Third flat part 81g... Protruding part 90... Single cell 91... Introduction hole 92... Introduction hole 93... Introduction hole 94... Outlet hole 95... Outlet hole 96... Outlet hole 171... First connecting part 173... Second connecting part 181a,281a Inclined part 181b... Flat part 382... Annular part 383... Extension part

Claims

1. A fuel cell stack including a stack body configured by stacking a plurality of unit cells each having a power generation section, a first separator, and a second separator, the unit being sandwiched between the first separator and the second separator, a metal detection terminal is provided between the first separator constituting the unit cell and the second separator of another unit cell adjacent to the unit cell, the metal detection terminal being inserted from the outer periphery of the unit cell; When the opposing surfaces of the first separator and the second separator are referred to as a first opposing surface and a second opposing surface, respectively, a first engaging portion is provided on the first opposing surface, the detection terminal has a base portion that abuts against the first opposing surface, an arm portion that protrudes from the base portion toward the second opposing surface and extends toward the rear side in the insertion direction of the detection terminal, and a second engagement portion that engages with the first engagement portion in a concave-convex relationship to prevent the detection terminal from coming off the stack main body, The arm portion abuts against the second opposing surface while being elastically deformed toward the first opposing surface. Fuel cell stack.

2. The first engagement portion protrudes toward the second opposing surface. The fuel cell stack of claim 1 .

3. a plurality of the first engaging portions are provided at intervals in the insertion direction, a plurality of the second engaging portions are provided corresponding to the first engaging portions, 3. The fuel cell stack according to claim 1 or 2.

4. The base portion and the arm portion protrude from the unit cell toward the outer periphery. The fuel cell stack according to any one of claims 1 to 3.

5. When the direction in which the unit cells are stacked is defined as the stacking direction, an electrically insulating sheet member surrounding the power generation section is provided between the first separator and the second separator constituting the unit cell; the detection terminals are provided on both sides of the unit cell in the stacking direction, the detection terminal has a protruding portion that protrudes outward from an edge of each of the first separator and the second separator, The sheet member has a cover portion that covers the protruding portion in the stacking direction. The fuel cell stack according to any one of claims 1 to 4.

6. The protruding portion is provided with a mark at a position of a tip of the cover portion in the insertion direction, the mark indicating that the detection terminal is inserted to a correct position. The fuel cell stack according to claim 5 .

7. The mark is a tip of the protruding portion. The fuel cell stack according to claim 6 .

8. The present invention is applied to a fuel cell stack including a stack body formed by stacking a plurality of unit cells each having a power generation section, a first separator, and a second separator, the unit being sandwiched between the first separator and the second separator, the unit being sandwiched between the first separator and the second separator, the metal detection terminal being inserted from the outer periphery of the unit cell between the first separator constituting the unit cell and the second separator of another unit cell adjacent to the unit cell, When the opposing surfaces of the first separator and the second separator are referred to as a first opposing surface and a second opposing surface, respectively, the detection terminal has a base portion that contacts the first opposing surface, an arm portion that protrudes from the base portion toward the second opposing surface and extends toward the rear side in the insertion direction of the detection terminal, and an engaging portion that engages in a concave-convex relationship with an engaged portion provided on the first opposing surface to prevent the detection terminal from coming off the stack main body, The arm portion abuts against the second opposing surface while being elastically deformed toward the first opposing surface. Detection terminal for fuel cell stack.

Images