JP3870724B2 - Fuel cell vehicle mounting structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure in which a fuel cell is mounted on a vehicle, and more particularly, to protection of a power supply extraction portion of a fuel cell at the time of a collision.
[0002]
[Prior art]
In recent years, automobiles using a fuel cell as a driving energy source have attracted attention as one approach to environmental problems, and a prototype has been made. For example, a fuel cell vehicle in which a fuel cell is mounted near the center of the vehicle, such as a space under the seat, has been prototyped in consideration of the vehicle weight balance and arrangement space. Recently, it has been studied to mount a fuel cell in the front part of the vehicle. Fuel cell vehicles are under development for practical use and dissemination in the near future.
[0003]
[Problems to be solved by the invention]
When the fuel cell is mounted in the front part of the vehicle, it is necessary to consider the protection of the fuel cell in the event of a vehicle collision. In particular, the fuel cell power take-out part has a high voltage, and around the power take-out part, a relay and an electric circuit for cutting off the current for safety and a distributor for supplying hydrogen, air, etc. into the fuel cell are arranged. Therefore, the need for protection is high.
[0004]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vehicle-mounted structure of a fuel cell that can reduce damage to the fuel cell in the event of a vehicle collision.
[0005]
[Means for Solving the Problems]
In the vehicle-mounted structure of the fuel cell according to the present invention, the fuel cell includes a fuel cell stack and a power supply extraction unit electrically connected to the fuel cell stack, and the power supply extraction unit includes the fuel cell. An end electrode stacked on the stack, and an output terminal provided on the periphery of the end electrode, and the fuel cell stack includes two rows arranged in parallel in the same stacking direction. The stacks are electrically connected to each other at one end side in the stacking direction, and an output terminal is provided for each stack at the other end side in the stacking direction, and the two rows of stacks are arranged in the front-rear direction of the vehicle at the front portion of the vehicle. Arranged side by side, the output terminal of one of the two rows of stacks is provided on the other stack side of the peripheral edge of the end electrode, and the output of the other stack of the two rows of stacks Child is provided on one stack side of the peripheral edge of the end electrodes.
[0006]
The impact force in the front-rear direction is large in a collision during travel of the vehicle. Therefore, in the event of a collision, the collision between the fuel cell and the devices and components arranged in the front and back of the fuel cell, and the pressure in the front-rear direction can particularly damage the fuel cell. According to the present invention, since the power supply take-out portion is arranged at the side of the vehicle, it is difficult to receive the impact force in the front-rear direction as described above, and damage is avoided or reduced.
[0007]
In another fuel cell mounting structure for a fuel cell according to another aspect of the invention, the fuel cell is formed of a single cell stack that is supported by rigid end plates at both ends in the stacking direction, and the stacking direction is the left and right of the vehicle. The power take-out part has a take-out electrode that is electrically connected to the unit cell stack and protrudes outward from the end plate through an opening provided in the end plate.
[0008]
The present invention utilizes the fact that the end plate provided at the end of the fuel cell in the stacking direction is made of a rigid member so as to exert a pressing force on the unit cell stack. That is, the end plate is strong against a compressive force in a direction parallel to the surface thereof. Therefore, by arranging the end plate so that the surface of the end plate is along the vehicle front-rear direction, the end plate can be resisted. In particular, the configuration in which the lead-out electrode connected to the cell stack through the opening in the end plate is led to the outside is arranged near the center of the end plate surface. Less susceptible to attacks by neighboring devices that hit the end of the direction.
[0009]
A preferred aspect of the present invention is a vehicle mounting structure in which a relay that cuts off a current from the fuel cell in accordance with a control signal from the outside is disposed on an outer surface of the end plate. By disposing the relay on the end plate which is not easily destroyed at the time of collision, the relay can be prevented from being damaged. As a result, the operation of the relay, such as leakage leakage, is ensured even after a collision, and safety is improved. Even if the relay is disconnected, a high voltage is applied between the relay and the extraction electrode. However, according to the present invention, the distance between the relay and the extraction electrode can be shortened. That is, since there are few portions that are kept at a high voltage when the relay is disconnected, safety is improved in that sense.
[0010]
In another fuel cell mounting structure for a fuel cell, the relay and the extraction electrode are connected by a flexible wiring member.
[0011]
The unit cell stack changes its dimension in the stacking direction due to expansion, contraction, etc. according to a temperature change due to its own heat generation, and the dimension may vary depending on manufacturing variations. On the other hand, the end plate is fixed to the vehicle body side. Therefore, the extraction electrode advances and retreats with respect to the end plate, and the protruding amount can be different. According to the present invention, since the wiring connecting the extraction electrode and the relay has flexibility, it can follow the advance and retreat of the extraction electrode, and can absorb the difference in the protruding amount due to manufacturing variation. Connection is hard to break.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0013]
FIG. 1 is a schematic top view of a front portion of a fuel cell vehicle employing a fuel cell vehicle mounting structure according to the present invention. In the figure, a fuel cell module 20 is arranged in an engine room in the front part of the vehicle. The fuel cell module 20 has a fuel cell stack 24 in a fuel cell stack case 22 (hereinafter simply referred to as case 22). Note that the case 22 originally encloses the fuel cell stack 24, but for convenience of explanation, the upper surface of the case 22 is removed and the structure of the internal fuel cell stack 24 and the like is shown for the sake of explanation.
[0014]
The fuel cell stack 24 includes a first stack 26 and a second stack 28 that are each a laminated body of plate-shaped unit cells 25 arranged in parallel. Here, both the stacking directions of the first stack 26 and the second stack 28 are the left and right directions of the vehicle, and are relatively thick (for example, about 15 mm thick) metal end plates 30 and 32 disposed at the left and right ends thereof. The stacks 26 and 28 are pressed in the stacking direction. The stack 26 and the stack 28 are stacked so that the polarities of the cells are opposite to each other. For example, the stack 26 has a positive electrode on the left side and a negative electrode on the right side, and the stack 28 has a negative electrode on the left side and a positive electrode on the right side. . The end portions on the end plate 32 side of the stack 26 and the stack 28 are electrically connected to each other, whereby both the stacks 26 and 28 constitute one single cell series connection body, and a desired high voltage is obtained.
[0015]
End electrodes 34 and 36 of a common unit cell serial connection body constituted by the stacks 26 and 28 are stacked on the end portions of the stack 26 and the stack 28 on the end plate 30 side. For example, according to the arrangement direction of the unit cells described above, the electrode 34 stacked on the stack 26 is a positive electrode, and the electrode 36 stacked on the stack 28 is a negative electrode. The electrodes 34 and 36 have an L-shape that is bent in the stacking direction of the stack at the position of the boundary between the stack 26 and the stack 28 (that is, the center of the fuel cell stack 24 with respect to the vehicle longitudinal direction). A portion of the electrodes 34, 36 facing the stacking direction is projected from the end plate 30 toward the vehicle side through a hole formed at the center position in the vehicle longitudinal direction of the end plate 30, and used as a terminal 38.
[0016]
FIG. 2 is a schematic perspective view showing the structure of the power supply extraction portion including the opening provided in the end plate 30 and the electrodes 34 and 36 extracted through the opening. The end plate 30 is provided with two vertically long openings 39 at the center in the vehicle longitudinal direction. For example, the terminal 38a of the electrode 34 protrudes outward through the upper opening 39a, and the terminal 38b of the electrode 36 protrudes outward through the lower opening 39b.
[0017]
The end plates 30 and 32 are fixed to the case 22, but the stacks 26 and 28 may change the dimensions in the stacking direction due to expansion and contraction due to temperature. Therefore, a disc spring laminated body (not shown) is disposed between the end plate 30 and the electrode 34 and between the end plate 30 and the electrode 36, and the unit cells constituting the stacks 26 and 28 are always appropriate. It is configured to be pressed against each other with a sufficient force.
[0018]
In addition to the relay 40, an electric circuit and a distributor (not shown) are disposed on the end plate 30. The relay 40 is electrically connected to the positive and negative terminals 38 taken out from the opening 39 of the end plate 30 by a flexible bus bar (referred to as a flexible bus bar) 42. Incidentally, the flexible bus bar 42 is bolted to the terminal 38 and the terminal of the relay 40, respectively. The relay 40 is provided to electrically cut off the output from the fuel cell module 20 in accordance with an external control signal. For example, the relay 40 is kept in an ON state during normal times such as when the vehicle is running, and enables output from the fuel cell module 20, while a collision sensor (not shown) detects a collision of the host vehicle. Is switched to the OFF state in accordance with a control signal issued to the engine, and the output from the fuel cell module 20 is cut off.
[0019]
Now, in the case of a collision during travel of the vehicle, the impact force in the front-rear direction is usually large. Therefore, by arranging the relay 40 and the like on the surface of the end plate 30 facing the vehicle side in this way, it is difficult to receive the impact force in the front-rear direction, and the breakage of these parts is avoided or reduced. . In particular, since the end plate 30 is made of a rigid member so as to exert a pressing force on the fuel cell stack 24 as described above, it is strong against a compressive force in a direction parallel to the surface. Here, the end plate 30 arranged along the vehicle front-rear direction can withstand the compressive force in the vehicle front-rear direction, and is not easily deformed or destroyed. It is suitably protected. In particular, as described above, the relay 40 has a role of being interrupted at the time of a collision to prevent leakage, and by protecting this, the safety is improved.
[0020]
Here, as a configuration for connecting the relay 40 and the like disposed on the end plate 30 and the fuel cell stack 24, a configuration in which the wiring is bypassed outside the end plate 30 can be considered. There is a possibility that the wiring is sandwiched between the end plate 30 and the adjacent device that hits the side of the end plate 30 in the front-rear direction of the vehicle. On the other hand, in the configuration in which the terminal 38 of the extraction electrode connected to the fuel cell stack 24 is guided to the outside through the opening 39 opened in the end plate 30 as in the present fuel cell module 20, the terminal 38 is on the end plate surface. Located near the center, it is less susceptible to attacks by adjacent devices that hit the end plate 30 from the front-rear direction of the vehicle in the event of a vehicle collision.
[0021]
Even when the relay 40 is disconnected, a high voltage is applied to the wiring between the output extraction electrode of the fuel cell stack 24 and the relay 40. In this regard, in the configuration in which the terminal 38 is taken out from the central opening 39 of the end plate 30 and connected to the relay 40 by the flexible bus bar 42, the wiring length between the terminal 38 and the relay 40 is short. That is, it can be said that the safety is high because there are few portions that are maintained at a high voltage when the relay is disconnected.
[0022]
A service plug 50 is attached to a position closer to the vehicle rear side of the side surface of the case 22 in the vehicle side direction (side surface on the end plate 30 side). The service plug 50 includes a fixing portion 52 fixed to the case 22 and a plug portion 54 provided outside the case 22 and separable from the fixing portion 52. A terminal block 60 is mounted on the end plate 30 at a position close to the service plug 50, and the fixed portion 52 of the service plug 50 and the relay 40 are electrically connected using the terminal block 60 as a relay point. That is, the harness 62 connected to the fixed portion 52 and the bus bar 64 connected to the relay 40 are electrically connected to each other at the terminal block 60. Thereby, between the relay 40 and the fixing | fixed part of the service plug 50 is electrically connected for every positive electrode and negative electrode.
[0023]
Further, the power output cable 66 is drawn from the fixing portion 52 of the service plug 50 to the outside of the case 22. The harness 62 connected to the fixing portion 52 and the power output cable 66 are electrically connected when the plug portion 54 is attached, and disconnected when the plug portion 54 is pulled out. For example, when an operator pulls out the plug portion 54 to perform maintenance work, safety against electric leakage outside the fuel cell module 20 is ensured.
[0024]
Note that cooling water from a radiator (not shown) is circulated in the fuel cell module 20. The inlet 70 and the outlet 72 provided in the end plate 32 are for injecting and discharging the cooling water.
[0025]
Next, the flexible bus bar 42 will be described. As described above, the dimensions of the fuel cell stack 24 change in the stacking direction due to expansion and contraction according to the temperature change due to the heat generation of the fuel cell stack 24, and the dimensions may vary depending on manufacturing variations. On the other hand, the end plate is fixed to the vehicle body side. Therefore, the terminal 38 advances and retreats with respect to the end plate 30, and the protruding amount can be different. The flexible bus bar 42 is configured flexibly so as to follow the advance and retreat of the terminal 38 and absorb the difference in the protruding amount due to manufacturing variations. Thereby, the connection between the terminal 38 and the relay 40 is difficult to be disconnected.
[0026]
FIG. 3 is a schematic perspective view showing the structure of the flexible bus bar 42. The flexible bus bar 42 includes a flexible bus bar portion 80 and terminals 82 at both ends. The bus bar portion 80 is constituted by, for example, a net-like conductor 84 knitted from a copper fine wire or the like, and has flexibility. Further, a plurality of flat mesh conductors 84 are stacked in the bending direction. As a result, the cross-sectional area of the bus bar portion 80 can be increased without impairing flexibility, and a large current output from the fuel cell stack 24 can flow with low loss. In order to connect the vertically projecting terminal 38 from the end plate 30 and the relay 40 disposed beside the terminal 38, the bus bar portion 80 is bent into an L shape. The terminal 82 is clamped by sandwiching the end of the bus bar portion 80. A bolt hole 86 is formed in the terminal 82, and a bolt is passed through the terminal 82. The flexible bus bar 42 is fixed to the terminal 38 and the terminal of the relay 40 by this bolt.
[0027]
【The invention's effect】
According to the vehicle mounting structure of the fuel cell of the present invention, the possibility of damage to the power supply take-out part at the time of a collision is reduced by arranging the power take-out part of the fuel cell in the side of the vehicle. In particular, the structure in which the opening is provided in the end plate and the takeout terminal constituting the power supply takeout portion protrudes therefrom prevents the takeout terminal from being damaged due to the collision. Also, by arranging a relay on the end plate to prevent leakage, the extraction terminal and the relay are placed close to each other, and the length of the wiring between the extraction terminal and the relay is maintained at a high voltage when the relay is disconnected. The effect of improving the safety is obtained. By using a flexible wiring member to connect the take-out terminal and the relay, it absorbs the advance and retreat of the take-out terminal due to expansion and contraction of the cell stack, and the connection between the take-out terminal and the relay is disconnected. The effect of being difficult is obtained.
[Brief description of the drawings]
FIG. 1 is a schematic top view of a front portion of a vehicle of a fuel cell vehicle equipped with a fuel cell module according to the present invention.
FIG. 2 is a schematic perspective view showing a structure of a power supply extraction portion including an opening provided in an end plate and an electrode extracted through the opening.
FIG. 3 is a schematic perspective view showing a structure of a flexible bus bar.
[Explanation of symbols]
20 fuel cell module, 22 case, 24 fuel cell stack, 30, 32 end plate, 34, 36 end electrode, 38 terminal, 40 relay, 42 flexible bus bar, 50 service plug, 62 harness, 64 bus bar.

Claims (4)

A structure in which a fuel cell is mounted on a vehicle,
The fuel cell
A fuel cell stack;
A power take-out section electrically connected to the fuel cell stack;
Have
The power extraction unit includes an end electrode stacked on the fuel cell stack, and an output terminal provided at the periphery of the end electrode,
The fuel cell stack includes two rows of stacks arranged in parallel in the same stacking direction, and the two rows of stacks are electrically connected to each other on one end side in the stacking direction, and each of the stacks on the other end side in the stacking direction. Each stack has an output terminal,
The two rows of stacks are arranged side by side in the vehicle front-rear direction at the front of the vehicle, and the output terminal of one of the two rows of stacks is provided on the other stack side of the peripheral edge of the end electrode, The output terminal of the other stack of the two rows of stacks is provided on one stack side of the peripheral edges of the end electrodes.
A fuel cell mounting structure for a fuel cell. The vehicle mounting structure according to claim 1,
The two rows of stacks arranged in parallel in the same stacking direction are supported by a common end plate arranged at the end in the stacking direction, and two output terminals of the two rows of stacks are connected to the end plate. Projecting outward in the stacking direction through the provided opening,
A fuel cell mounting structure for a fuel cell. In the vehicle mounting structure according to claim 1 or 2,
A fuel cell mounting structure for a fuel cell, wherein a relay that cuts off a current from the fuel cell in response to an external control signal is disposed on an outer surface of the end plate. The vehicle mounting structure according to claim 3,
A fuel cell mounting structure for a fuel cell, wherein the relay and a power supply take-out portion of the fuel cell are connected by a flexible wiring member.

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