JP5144398B2 - Fuel cell stack - Google Patents

Description

  In the present invention, a laminate in which a plurality of unit cells each having an electrolyte / electrode structure and a separator each having a pair of electrodes provided on both sides of the electrolyte is accommodated in a box-shaped casing and disposed in a vehicle. The present invention relates to a fuel cell stack.

  For example, a polymer electrolyte fuel cell employs an electrolyte membrane (electrolyte) made of a polymer ion exchange membrane. A unit cell is configured by sandwiching an electrolyte membrane / electrode structure in which an anode side electrode and a cathode side electrode are disposed on both sides of the electrolyte membrane with a separator.

  Usually, a fuel cell is used as a fuel cell stack in which a predetermined number (for example, several tens to several hundreds) of unit cells are stacked in order to obtain a desired power generation. In this type of fuel cell stack, it is necessary to detect whether each unit cell has a desired power generation performance. For this reason, usually, an operation of detecting a cell voltage for each unit cell during power generation by connecting a cell voltage terminal provided in the separator to a voltage detection device (cell voltage monitor) is performed.

  For example, in Patent Document 1, a cell voltage monitor 2 is attached to the fuel cell 1 as shown in FIG. Each terminal (not shown) of the cell voltage monitor 2 is in contact with the metal plate 3 and detects the potential of the fuel cell 1.

  The fuel cell 1 is provided with a resin frame 4, and the resin frame 4 is provided with a retaining portion 5 for retaining the cell voltage monitor 2 from the fuel cell 1. A lead wire 6 is connected to a terminal of the cell voltage monitor 2, and this lead wire 6 is connected to a controller or the like (not shown).

JP 2004-87163 A

  By the way, the fuel cell stack may be used as an in-vehicle fuel cell stack mounted on a fuel cell vehicle in a state in which a stacked body in which a plurality of unit cells are stacked is housed in a box-shaped casing. In that case, in said cell voltage monitor 2, the conducting wire 6 is taken out outside through the opening part provided in the casing.

  Therefore, when an external load is applied to the fuel cell vehicle and the casing is deformed, the edge forming the opening is likely to contact the conductor 6. Thereby, there exists a problem that the coating | cover of the conducting wire 6 is damaged, for example.

  An object of the present invention is to solve this kind of problem, and to provide a fuel cell stack capable of suppressing damage to a cable connected to a cell voltage terminal in a simple and favorable manner. To do.

  In the present invention, a laminate in which a plurality of unit cells each having an electrolyte / electrode structure and a separator each having a pair of electrodes provided on both sides of the electrolyte is accommodated in a box-shaped casing and disposed in a vehicle. The present invention relates to a fuel cell stack.

  On at least one surface of the casing, in order to detect a cell voltage for each unit cell or for each unit cell, an opening is formed corresponding to a cell voltage terminal provided in the unit cell, The cable connected to the cell voltage terminal is provided with a protective member for protecting the cable.

  Then, when an external load is applied to the fuel cell stack, the length of the protective member is such that the edge portion forming the opening contacts the protective member in a state where the casing is deformed until it abuts against the inner wall of the vehicle. And the slack length of the cable is set.

  Moreover, it is preferable that the cable is provided with a breaking portion that is intensively cut when the casing is deformed to be larger than the deformed state.

  Furthermore, in the present invention, at least one surface of the casing has an opening corresponding to a cell voltage terminal provided in the unit cell in order to detect a cell voltage for each unit cell or for each unit cell. The cable connected to the cell voltage terminal is provided with a protective member for protecting the cable.

  The casing is provided to project between the casing and the cable toward the opening, and when the external deformation is applied to the fuel cell stack and the casing is deformed, the cable forms the opening. A protective sheet for preventing contact with the edge portion is provided.

  In the present invention, since the length of the protective member and the slack length of the cable are set, even if the casing is deformed by the application of an external load, the edge portion that forms the opening of the casing contacts the cable. There is nothing. For this reason, it becomes possible to suppress damage to the cable connected to the cell voltage terminal with a simple configuration.

  In the present invention, the protective sheet is provided on the casing so as to protrude toward the opening. Therefore, even if the casing is deformed by the application of an external load, the edge portion forming the opening does not contact the cable. Thereby, damage of the cable connected to the cell voltage terminal can be satisfactorily and reliably suppressed with a simple configuration.

  FIG. 1 is a partial side view of a fuel cell vehicle 12 on which a fuel cell stack 10 according to a first embodiment of the present invention is mounted.

  The fuel cell vehicle 12 is located between the left and right front seats (driver's seat and front passenger seat) 18a, 18b in the passenger compartment 16, and a center console 14 is provided. The center console 14 is connected to the fuel cell vehicle 12. Extending in the vehicle length direction (arrow L direction). The fuel cell stack 10 is accommodated in the center console 14.

  As shown in FIG. 2, the fuel cell stack 10 includes a stacked body 24 in which a plurality of unit cells 22 are stacked in the horizontal direction (arrow A direction). A terminal plate 26a, an insulating plate 28a, and an end plate 30a are sequentially disposed at one end of the stack 24 in the stacking direction (arrow A direction).

  At the other end in the stacking direction of the stacked body 24, a terminal plate 26b, an insulating plate 28b, and an end plate 30b are sequentially disposed outward. The fuel cell stack 10 is integrally held by a box-shaped casing 32 including end plates 30a and 30b configured in a vertically long rectangular shape as end plates. The end plates 30a and 30b are made of, for example, an aluminum plate.

  As shown in FIG. 3, each unit cell 22 includes an electrolyte membrane / electrode structure (electrolyte / electrode structure) 40, and a thin plate-shaped first and second metal sandwiching the electrolyte membrane / electrode structure 40. Separators 42 and 44 are provided. Instead of the first and second metal separators 42 and 44, a carbon separator may be used.

  In order to supply an oxidant gas, for example, an oxygen-containing gas, to one end edge (upper edge) in the long side direction (arrow C direction in FIG. 3) of the unit cell 22 in communication with each other in the arrow A direction. The oxidant gas supply communication hole 46a and a fuel gas supply communication hole 48a for supplying a fuel gas, for example, a hydrogen-containing gas, are provided.

  The other end edge (lower edge) in the long side direction of the unit cell 22 communicates with each other in the direction of the arrow A, and discharges the fuel gas discharge communication hole 48b for discharging the fuel gas and the oxidant gas. An oxidant gas discharge communication hole 46b is provided.

  A cooling medium supply communication hole 50a for supplying a cooling medium is provided at one end edge of the unit cell 22 in the short side direction (arrow B direction), and the other end edge of the unit cell 22 in the short side direction. Is provided with a cooling medium discharge communication hole 50b for discharging the cooling medium.

  The electrolyte membrane / electrode structure 40 includes, for example, a solid polymer electrolyte membrane 52 in which a perfluorosulfonic acid thin film is impregnated with water, and an anode side electrode 54 and a cathode side electrode 56 that sandwich the solid polymer electrolyte membrane 52. With.

  The anode side electrode 54 and the cathode side electrode 56 are uniformly coated with a gas diffusion layer (not shown) made of carbon paper or the like, and porous carbon particles carrying a platinum alloy on the surface thereof. And an electrode catalyst layer (not shown) formed. The electrode catalyst layers are formed on both surfaces of the solid polymer electrolyte membrane 52.

  A fuel gas flow path 58 that connects the fuel gas supply communication hole 48a and the fuel gas discharge communication hole 48b is formed along the arrow C direction on the surface 42a of the first metal separator 42 facing the electrolyte membrane / electrode structure 40. Is done. A cooling medium flow path 60 that communicates the cooling medium supply communication hole 50a and the cooling medium discharge communication hole 50b is formed on the surface 42b of the first metal separator 42 along the arrow B direction.

  The surface 44a of the second metal separator 44 facing the electrolyte membrane / electrode structure 40 is provided with an oxidant gas flow path 62 along the direction of arrow C, and the oxidant gas flow path 62 is provided with an oxidant gas supply. The communication hole 46a communicates with the oxidant gas discharge communication hole 46b. On the surface 44 b of the second metal separator 44, a cooling medium flow path 60 is integrally formed so as to overlap the surface 42 b of the first metal separator 42.

  A first seal member 64 a is integrally formed on the surfaces 42 a and 42 b of the first metal separator 42 around the outer peripheral edge of the first metal separator 42. A second seal member 64 b is integrally formed on the surfaces 44 a and 44 b of the second metal separator 44 around the outer peripheral edge of the second metal separator 44.

  A recess 66 is formed at one edge of the unit cell 22 in the short side direction (arrow B direction). For example, the first metal separator 42 is provided with a cell voltage terminal 68 disposed in the recess 66. Is done.

  As shown in FIG. 2, first and second power extraction terminals 70 a and 70 b are provided to extend outward in the stacking direction from the in-plane centers of the terminal plates 26 a and 26 b. The first power extraction terminal 70a penetrates the insulating plate 28a and the end plate 30a and protrudes outside, while the second power extraction terminal 70b penetrates the insulation plate 28b and the end plate 30b and protrudes outside. For example, a load such as a vehicle driving motor is connected to the first and second power extraction terminals 70a and 70b.

  The casing 32 includes end plates 30 a and 30 b that are end plates, a plurality of side plates 74 a to 74 d disposed on the side of the laminate 24, and end portions of the side plates 74 a to 74 d that are close to each other via screws 75. And an angle member 76 that is connected to each other, and a hinge mechanism 78 that connects the end plates 30a and 30b and the side plates 74a to 74d.

  The side plates 74a to 74d are composed of thin metal plates, and at least the side plate 74a has a pair of plate portions 80a and 80b that are divided into two parts in the vertical direction (arrow C direction) and are spaced apart from each other. An opening 82 is formed between the plate portions 80a and 80b, and an edge portion 82a is provided around the opening 82.

  The hinge mechanism 78 includes first hinge portions 84a and 84b provided on the end plates 30a and 30b, a second hinge portion 86 provided on the side plates 74a to 74d, and the first hinge portions 84a and 84b and the second hinge portion 86. Are provided with connecting pins 88a and 88b inserted in an alternately arranged state.

  An oxidant gas inlet manifold 90a that communicates with the oxidant gas supply communication hole 46a and a fuel gas inlet manifold 92a that communicates with the fuel gas supply communication hole 48a are provided on the upper side of the end plate 30a. An oxidant gas outlet manifold 90b that communicates with the oxidant gas discharge communication hole 46b and a fuel gas outlet manifold 92b that communicates with the fuel gas discharge communication hole 48b are provided on the lower side of the end plate 30a.

  Although not shown, the end plate 30b is provided with a cooling medium inlet manifold that extends in the direction of arrow C and communicates with the cooling medium supply communication hole 50a, and a cooling medium outlet manifold that communicates with the cooling medium discharge communication hole 50b. It is done.

  As shown in FIG. 4, a connector 94 is attached every predetermined number of cell voltage terminals 68. The connector 94 includes a connection terminal portion 96 connected to each cell voltage terminal 68, and the connection terminal portion 96 is coupled to one end of a cable (harness) 98 via a solder portion 100 (see FIG. 5). A connector cover 102 is attached to the connector 94, and an end portion of the connector cover 102 and a part of the cable 98 are fixed by a protective member 104 such as a heat shrinkable tube, for example.

  The connector cover 102 and the cable 98 are exposed to the outside of the side plate 74a from the opening 82, and the cable 98 extends upward along the plate portion 80b that constitutes the side plate 74a. And is fixed to the plate portion 80b, and a slack portion 108 is formed.

  In the first embodiment, as shown in FIG. 6, when an external load is applied to the fuel cell stack 10, the plate portion 80 b constituting the casing 32 is deformed until it abuts against the inner wall of the center console 14. The length L of the protection member 104 and the length of the slack portion 108 of the cable 98 are set so that the edge portion 82 a forming the opening 82 contacts the protection member 104.

  Furthermore, in the first embodiment, the center console 14 is also deformed, and the cable 98 is configured to be intensively cut by the solder portion 100 when the plate portion 80b is further deformed.

  The operation of the fuel cell stack 10 configured as described above will be described below.

  First, in the fuel cell stack 10, as shown in FIG. 2, an oxidant gas such as an oxygen-containing gas is supplied from the oxidant gas inlet manifold 90a of the end plate 30a to the oxidant gas supply communication hole 46a, and the fuel gas A fuel gas such as a hydrogen-containing gas is supplied from the inlet manifold 92a to the fuel gas supply communication hole 48a. On the other hand, a cooling medium such as pure water or ethylene glycol is supplied from the cooling medium inlet manifold of the end plate 30b to the cooling medium supply communication hole 50a.

  Therefore, in the stacked body 24, the oxidant gas, the fuel gas, and the cooling medium are supplied in the arrow A direction to the plurality of unit cells 22 that are overlapped in the arrow A direction.

  As shown in FIG. 3, the oxidant gas is introduced into the oxidant gas flow path 62 of the second metal separator 44 through the oxidant gas supply communication hole 46 a, and along the cathode side electrode 56 of the electrolyte membrane / electrode structure 40. Move. On the other hand, the fuel gas is introduced into the fuel gas flow path 58 of the first metal separator 42 from the fuel gas supply communication hole 48 a and moves along the anode side electrode 54 of the electrolyte membrane / electrode structure 40.

  Therefore, in each electrolyte membrane / electrode structure 40, the oxidant gas supplied to the cathode side electrode 56 and the fuel gas supplied to the anode side electrode 54 are consumed by an electrochemical reaction in the electrode catalyst layer, Power generation is performed.

  Next, the oxidant gas consumed by being supplied to the cathode side electrode 56 flows along the oxidant gas discharge communication hole 46b, and then is discharged to the outside from the oxidant gas outlet manifold 90b of the end plate 30a. Similarly, the fuel gas consumed by being supplied to the anode electrode 54 flows along the fuel gas discharge communication hole 48b, and is then discharged to the outside from the fuel gas outlet manifold 92b of the end plate 30a.

  The cooling medium flows in the direction of arrow B after being introduced into the cooling medium flow path 60 between the first and second metal separators 42 and 44 from the cooling medium supply communication hole 50a. After cooling the electrolyte membrane / electrode structure 40, the cooling medium moves through the cooling medium discharge communication hole 50b and is discharged from the cooling medium outlet manifold of the end plate 30b.

  In this case, in the first embodiment, as shown in FIG. 5, the connector 94 connected to the predetermined number of cell voltage terminals 68 is provided with a protective member 104 at the end of the connector cover 102 and a part of the cable 98. In addition, the length L of the protective member 104 and the length of the slack portion 108 of the cable 98 are set in advance.

  For this reason, as shown in FIG. 6, when an external load is applied to the fuel cell stack 10, the plate portion 80 b constituting the casing 32 may be deformed until it abuts against the inner wall of the center console 14. At that time, although the cable 98 is sandwiched between the inner wall of the center console 14 and the edge portion constituting the opening portion 82 of the plate portion 80 b, the protective member 104 that protects the cable 98 from turning around the opening portion 82. It is in contact with the edge portion to be formed.

  Therefore, the cable 98 is not damaged and the cable 98 and the plate portion 80b are not electrically connected. Thereby, the effect that it becomes possible to suppress the damage of the cable 98 favorably and reliably with a simple configuration is obtained.

  Next, after the plate portion 80b comes into contact with the inner wall of the center console 14, it returns to the laminated body 24 side (see FIG. 7). Here, since the length of the slack portion 108 is set in advance, the cable 98 is stretched so as not to be slack when the plate portion 80b is deformed. Therefore, when the plate part 80b returns to the laminated body 24 side, there is an advantage that the cable 98 is not wound on the opening part 82 side and damage to the cable 98 is suppressed as much as possible.

  Further, in the first embodiment, when the external load is relatively large and the center console 14 is deformed from the position of the solid line to the position of the two-dot chain line in FIG. 6, the deformed state of the plate portion 80b is the position of FIG. Will be even bigger. At that time, since the cable 98 is further pulled from a predetermined tension state, it can be ruptured intensively at the solder portion 100. As a result, energization of the cable 98 is stopped, the short circuit of the cable 98 is prevented, and the insulation distance of the high voltage portion can be secured.

  FIG. 8 is an explanatory cross-sectional view of a main part of the fuel cell stack 120 according to the first embodiment of the present invention. The same components as those of the fuel cell stack 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the second embodiment, a protective sheet 122 is provided on the surface of the plate portion 80 b constituting the casing 32 so as to protrude toward the opening 82 between the plate portion 80 b and the cable 98. The protective sheet 122 is made of, for example, silicon rubber containing glass cloth or EPDM (ethylene / propylene rubber). This is to prevent the protective sheet 122 from being damaged by hitting the edge portion 82a. The protective sheet 122 protrudes into the opening 82 by a predetermined distance T and is separated from the protective member 104 by a distance d (T ≧ d). This is to prevent the end portion of the protection sheet 122 from rolling and entering between the protection member 104 and the plate portion 80b.

  In the second embodiment configured as described above, when an external load is applied to the fuel cell stack 120, the plate portion 80 b is deformed to the inner wall side of the center console 14 as shown in FIG. 9. At that time, the protective sheet 122 provided on the surface of the plate portion 80b covers the edge portion forming the opening portion 82 of the plate portion 80b, and the cable 98 does not directly contact the edge portion.

  Thereby, with the simple configuration, damage to the cable 98 can be reliably and reliably suppressed, and the same effects as those of the first embodiment can be obtained, such as prevention of a short circuit of the cable 98.

  In the first and second embodiments, the fuel cell stacks 10 and 120 are disposed on the center console 14 in the passenger compartment 16, but the present invention is not limited to this. For example, it can be accommodated in the front part (bonnet part) of the fuel cell vehicle 12 or the lower floor of the fuel cell vehicle 12.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial side view of a fuel cell vehicle on which a fuel cell stack according to a first embodiment of the present invention is mounted. It is a perspective view of the fuel cell stack. It is a disassembled perspective explanatory drawing of the unit cell which comprises the said fuel cell stack. It is a perspective view which shows the connection state of the cell voltage terminal and connector which comprise the said fuel cell stack. It is principal part sectional drawing which shows the connection state of the said cell voltage terminal and the said connector. It is explanatory drawing of the state which the casing which comprises the said fuel cell stack deform | transformed. It is explanatory drawing of the state which the deformed casing returned. It is principal part cross-sectional explanatory drawing of the fuel cell stack which concerns on the 2nd Embodiment of this invention. It is explanatory drawing of the state which the casing which comprises the said fuel cell stack deform | transformed. It is explanatory drawing of the attachment structure of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 120 ... Fuel cell stack 12 ... Fuel cell vehicle 14 ... Center console 18a, 18b ... Front seat 22 ... Unit cell 24 ... Laminated body 30a, 30b ... End plate 32 ... Casing 40 ... Electrolyte membrane electrode assembly 42, 44 ... Metal separator 52 ... Solid polymer electrolyte membrane 54 ... Anode side electrode 56 ... Cathode side electrode 58 ... Fuel gas passage 60 ... Cooling medium passage 62 ... Oxidant gas passage 68 ... Cell voltage terminals 74a to 74d ... Side plate 76 ... Angle member 78 ... Hinge structure 94 ... Connector 96 ... Connection terminal part 98 ... Cable 100 ... Solder part 102 ... Connector cover 104 ... Protective member 108 ... Loose part 122 ... Protective sheet

Claims (3)

A fuel cell stack disposed in a vehicle while accommodating a stacked body in which a plurality of unit cells each having an electrolyte / electrode structure and a separator each having a pair of electrodes provided on both sides of the electrolyte are stacked in a box-shaped casing There,
In at least one surface of the casing, an opening is formed corresponding to a cell voltage terminal provided in the unit cell in order to detect a cell voltage for each unit cell or for each unit cell. ,
The cable connected to the cell voltage terminal is provided with a protective member for protecting the cable,
When an external load is applied to the fuel cell stack, the protective member is configured such that an edge portion forming the opening contacts the protective member in a state in which the casing is deformed until it abuts against an inner wall of the vehicle. And a slack length of the cable are set.   2. The fuel cell stack according to claim 1, wherein the cable is provided with a broken portion that is intensively cut when the casing is deformed to a greater extent than the deformed state. 3. A fuel cell stack disposed in a vehicle while accommodating a stacked body in which a plurality of unit cells each having an electrolyte / electrode structure and a separator each having a pair of electrodes provided on both sides of the electrolyte are stacked in a box-shaped casing There,
In at least one surface of the casing, an opening is formed corresponding to a cell voltage terminal provided in the unit cell in order to detect a cell voltage for each unit cell or for each unit cell. ,
The cable connected to the cell voltage terminal is provided with a protective member for protecting the cable,
The casing is provided between the casing and the cable so as to protrude toward the opening, and when the external deformation is applied to the fuel cell stack and the casing is deformed, the cable opens the opening. A fuel cell stack comprising a protective sheet for preventing contact with an edge portion to be formed.

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