JP2004055384A - Fuel cell module equipped with electric leak detector, and fuel cell automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a wire from an electric leak detector from interfering with other components by improving the reliability of electric leak checking. <P>SOLUTION: This fuel cell module 20 is so structured that a case 22 for covering a fuel cell stack 24 is formed, and the electric leak detector 40 is installed in the case 22. A wire 42 for a high voltage for connecting the leak detector 40 to the cell stack 24 is prevented from interfering with other components such as a relay. The leak detector 40 is preferably installed on an end plate 30. The wire 42 is preferably fixed to the end plate 30 with a bolt. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel cell module including a leakage detector and a fuel cell vehicle equipped with the fuel cell module.
[0002]
[Prior art]
Fuel cells, which generate electricity by using an electrochemical reaction between hydrogen and oxygen, are expected as next-generation energy sources, and are being studied for use in vehicles. In such a fuel cell vehicle, since the fuel cell generates a high voltage, it is important to take measures against leakage from the fuel cell. Japanese Patent Laying-Open No. 6-223859 discloses a configuration in a fuel cell vehicle in which electric conductivity of cooling water is detected by a conductivity sensor to check for leakage from the fuel cell.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional technique, the reliability of the conductivity check may be reduced. This is because the leakage detector composed of the conductivity sensor involves wiring from the fuel cell, so depending on the arrangement of the leakage detector, the wiring may be routed due to interference with other parts. This is because it becomes difficult, and as a result, the reliability of the leakage check may be reduced.
[0004]
The present invention has been made in view of the above-described problem, and has as its object to prevent wiring from an electric leakage detector from interfering with other components, thereby improving the reliability of an electric leakage check.
[0005]
[Means for Solving the Problems and Their Functions and Effects]
As means for solving at least a part of the above-described problem, the following configuration is adopted.
[0006]
The first fuel cell module of the present invention comprises:
In a fuel cell module including a fuel cell that supplies driving power of a vehicle and a leakage detector that detects leakage from the fuel cell,
A case is provided to cover the fuel cell,
The gist is that the earth leakage detector is provided in the case.
[0007]
In the first fuel cell module, since the leakage detector is provided in the case that covers the fuel cell, the wiring connecting the leakage detector and the fuel cell does not interfere with other components. For this reason, since the routing of the wiring is easy, the reliability of the leakage check can be improved.
[0008]
In the first fuel cell module, the fuel cell is composed of a stack of unit cells supported at both ends in a stacking direction by end plates having high rigidity, and the leakage detector is disposed on the end plate. Configuration.
[0009]
According to this configuration, since the leakage detector is provided on the end plate, it is possible to shorten the electric wiring connecting the leakage detector and the fuel cell. For this reason, since a high voltage part including an electric wiring is shortened, safety can be improved.
[0010]
The second fuel cell module of the present invention comprises:
In a fuel cell module including a fuel cell that supplies driving power of a vehicle and a leakage detector that detects leakage from the fuel cell,
The fuel cell includes a stack of unit cells supported at both ends in the stacking direction by end plates having high rigidity,
The gist is that the earth leakage detector is provided on the end plate.
[0011]
In the second fuel cell module, since the leakage detector is provided on the end plate, the electric wiring connecting the leakage detector and the fuel cell is shortened, and interference with other components can be prevented. . For this reason, since the wiring can be easily arranged, the reliability of the leakage check can be improved. Further, the high-voltage portion including the electric wiring can be shortened, so that the safety can be improved. be able to.
[0012]
In the first or second fuel cell module, the fuel cell is configured to charge the end plate to an intermediate potential, and the electric leakage detector directly connects an electric wire to the end plate, and A configuration may be adopted in which the intermediate potential of the fuel cell is drawn through wiring.
[0013]
According to this configuration, the electric wiring for drawing the intermediate potential to the leakage detector can be minimized. For this reason, the high-voltage portion including the wiring is shortest, so that the safety can be further improved.
[0014]
The fuel cell vehicle of the present invention,
A fuel cell vehicle equipped with a first fuel cell module or a second fuel cell module provided with the leakage detector on an end plate,
The gist is that the fuel cell module is mounted so that the stacking direction of the fuel cells is oriented in the left-right direction of the vehicle.
[0015]
In this fuel cell vehicle, the leakage detector is disposed on the high-rigidity end plate, and the fuel cell module is mounted so that the stacking direction of the fuel cells is oriented in the left-right direction of the vehicle. Can be prevented from being damaged. At the time of a collision, a large impact force is generated in the front-rear direction of the vehicle, and there is a small possibility that a large impact force will be generated in the left and right direction where the leakage detector is provided. This is because it is arranged on the plate.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described based on examples. FIG. 1 is a schematic top view of a vehicle front part of a fuel cell vehicle equipped with a fuel cell module as one embodiment of the present invention. In the figure, a fuel cell module 20 is arranged in an engine room at a front part of a 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). Although the case 22 originally contains the fuel cell stack 24 in a sealed state, the upper surface of the case 22 is removed for convenience of explanation, and the structure of the internal fuel cell stack 24 and the like is shown.
[0017]
The fuel cell stack 24 is for supplying driving power to the vehicle, and is configured by arranging a first stack 26 and a second stack 28, each of which is a stacked body of plate-like unit cells 25, in parallel. . The first and second stacks 26 and 28 are composed of the same number of cells and are configured to generate the same voltage. Here, the lamination direction of the first and second stacks 26, 28 is both the vehicle left-right direction, and relatively thick (for example, about 15 mm thick) metal end plates 30, 32 are provided at the left and right ends. Are located. The two end plates 30, 32 are fastened by a fastening member (not shown), and as a result, the stacks 26, 28 are pressed in the stacking direction.
[0018]
The first and second stacks 26 and 28 are stacked so that the polarities of the cells are opposite to each other. For example, the first stack 26 has a positive electrode on the left side and a negative electrode on the right side in FIG. In the drawings, the left side is the negative electrode, and the right side is the positive electrode. The ends of the first and second stacks 26 and 28 on the end plate 32 side are electrically connected to each other, whereby the two stacks 26 and 28 constitute one unit cell series connection body and have a desired high voltage. Is obtained.
[0019]
End electrodes 34, 36 of a common unit cell connected in series constituted by the first and second stacks 26, 28 are laminated on the end portions of the first and second stacks 26, 28 on the end plate 30 side. Is done. For example, according to the arrangement direction of the unit cells described above, the electrode 34 stacked on the first stack 26 becomes a positive electrode, and the electrode 36 stacked on the second stack 28 becomes a negative electrode. The electrodes 34 and 36 are L-shaped bent in the stacking direction of the stack at the position of the boundary between the first and second stacks 26 and 28 (that is, the center of the fuel cell stack 24 in the vehicle longitudinal direction). Having. Portions of the electrodes 34 and 36 facing the stacking direction are projected from the end plate 30 toward the vehicle side through holes formed at the center of the end plate 30 in the vehicle longitudinal direction, and are used as terminals 38.
[0020]
The dimensions of the first and second stacks 26 and 28 in the stacking direction may change due to expansion and contraction due to temperature. Therefore, between the end plate 30 and the electrode 34 and between the end plate 30 and the electrode 36, a laminated body of disc springs (not shown) is arranged, and the first and second stacks 26 and 28 are formed. It is configured such that the constituent cells are always pressed against each other with an appropriate force.
[0021]
A power output cable (not shown) is connected to the terminal 38. A relay (not shown) is provided in the middle of the power output cable. On the end plate 30 on the side where the terminal 38 protrudes, the leakage detector 40 is arranged in a fixed state. The wiring 42 extends from the electric leakage detector 40, and the end of the wiring 42 is bolted to the end plate 30. FIG. 2 is a perspective view showing the state of the bolting. As shown in the figure, the end 42 a of the wiring 42 is fixed to a mounting bracket 44, and a bolt 46 is passed through a hole (not shown) provided in the mounting bracket 44, so that the end plate 30 is located on the side of the end plate 30 on the vehicle side. Is bolted to the wall surface 30a.
[0022]
A pipe is provided between the fuel cell module 20 and a radiator (not shown), and cooling water is circulated. The cooling water air-cooled by the radiator flows into the fuel cell stack 24 from the inlet 50, flows through the gap provided in the stack, takes heat generated by the combustion of hydrogen, and flows out from the outlet 52. Is returned to the radiator again. Since the cooling water flows in the fuel cell stack 24 while being in contact with the electrode of the unit cell, the cooling water is affected by the potential of the electrode, and the cooling water flows between the positive potential (+ V) of the electrode 34 and the negative potential (−V) of the electrode 36. Take the potential of. For example, when the inlet 50 and the outlet 52 are provided on the end plate 32 opposite to the end plate 30 from which the terminal 38 protrudes, the cooling water basically has a potential (approximately zero potential) near the end plate 32. Will be.
[0023]
As described above, the gap between the end plates 30 and 32 is fastened by a fastening member, which is formed of a conductive metal. The end plate 30 also has the same potential (approximately zero potential) as the other end plate 30.
[0024]
FIG. 3 is an explanatory diagram showing the electrical configuration of the leakage detector 40 together with the fuel cell stack 24 and an electronic control unit (hereinafter, referred to as an ECU) 54. As illustrated, the leakage detector 40 is connected to the intermediate potential (about zero potential) of the fuel cell stack 24. This is achieved by bolting the wiring 42 from the leakage detector 40 to the end plate 30 as described above.
[0025]
The leakage detector 40 includes resistors 61 and 62, a voltage detection circuit 63, and a warning output circuit 64. According to the leakage detector 40, the intermediate potential from the wiring 42 is pulled in via the resistor 60, the voltage of the intermediate potential is detected by the voltage detection circuit 63, and a warning is issued according to the detection result. The output circuit 64 outputs a warning signal to the ECU 54. The resistor 60 and the voltage detection circuit 63 are connected to the ground by the resistor 62.
[0026]
If a leak or an electric shock occurs in the negative electrode 36 of the fuel cell stack 24, a current may flow between the electrode 36 and the above-described cooling water (the resistance component L in the figure). That is, when a circuit connecting the negative electrode 36 of the fuel cell stack 24 and the cooling water L is established, there is a possibility that a leakage current flows there. As a result, a high voltage is generated in the cooling water L, and the high voltage is detected by the voltage detection circuit 63.
[0027]
When a high voltage is generated in the voltage detection circuit 63, a warning signal is issued from the warning output circuit 64 to the ECU 54 as described above. The ECU 54 is configured by a so-called microcomputer including a CPU, a ROM, a RAM, and the like, and is provided outside the case 22. The CPU of the ECU 54 executes the control process according to the program stored in the ROM, and disconnects the relays 71 and 72 provided on the fuel cell stack 24 to the power output cable when receiving the warning signal.
[0028]
As described in detail above, according to the fuel cell module 20 of this embodiment, since the leakage detector 40 is provided in the case 22 that covers the fuel cell stack 24, the leakage detector 40 and the fuel cell stack 24 Does not interfere with other components such as a relay. For this reason, since the routing of the wiring is easy, the reliability of the leakage check can be improved.
[0029]
Further, in this embodiment, since the leakage detector 40 is provided on the end plate 30, the wiring 42 connecting the leakage detector 40 and the fuel cell stack 24 can be shortened. For this reason, the high voltage portion including the wiring 42 is shortened, so that safety can be improved. Particularly, in this embodiment, since the wiring 42 is directly fixed to the end plate 32 having an intermediate potential by bolting, the wiring 42 can be minimized. For this reason, the high-voltage portion including the wiring is minimized, so that the safety can be further improved.
[0030]
Further, according to the fuel cell vehicle equipped with the fuel cell module 20 of this embodiment, the leakage detector 40 is disposed on the end plate 30 and the stacking direction of the cells 25 of the fuel cell stack 24 is set to the direction of the vehicle. Since the fuel cell module 20 is mounted so as to face in the left-right direction, it is possible to prevent the leakage detector 40 from being damaged at the time of collision. At the time of a collision, a large impact force is generated in the front-rear direction of the vehicle, and there is a small possibility that a large impact force is generated in the left-right direction in which the electric leakage detector 40 is provided. This is because it is disposed on a highly rigid end plate such as a thick metal.
[0031]
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist of the present invention, and for example, the following modifications are possible.
[0032]
(1) In the above-described embodiment, the case 22 covers the entire fuel cell stack 24. Alternatively, the case 22 may cover a part of the fuel cell stack 24. For example, the case may be one that mainly covers the portion that is visible when the hood is opened, that is, the case covers the upper surface, or the upper surface and the side surface of the fuel cell stack 24, while the lower side is open.
[0033]
(2) In the above-described embodiment, the wiring 42 is directly attached to the end plate 32 having an intermediate potential by bolting. However, the wiring 42 is brazed to the end plate 32 instead. It may be configured. It may be configured to be directly attached by any method.
[0034]
(3) In the above-described embodiment, the end plate to which the wiring 42 is directly attached is the end plate 30 on the side from which the terminal 38 protrudes. Alternatively, the end plate 32 on the other side may be used.
[0035]
(4) In addition, the leakage detector 40 may be provided in the case 22 without directly attaching the wiring 42 to the end plate 30 (or 32).
[0036]
(5) The case 22 is not always necessary, and a configuration in which the leakage detector 40 is disposed on the end plate 30 (or 32) can be adopted as the invention.
[0037]
(6) The leakage detector 40 is configured to detect the leakage from the voltage fluctuation of the fuel cell stack 24. Alternatively, the leakage detector 40 may be configured to detect the electric conductivity of the cooling water. Any structure may be used as long as leakage from the fuel cell stack 24 can be detected.
[0038]
(7) In the above-described embodiment, the stacking direction of the cells 25 of the fuel cell stack 24 is set to be in the left-right direction of the vehicle, but the right-left direction is a direction perpendicular to the front-rear direction of the vehicle. However, the angle is not necessarily required to be a right angle, and if the angle is substantially a right angle, the direction is referred to as a left-right direction.
[Brief description of the drawings]
FIG. 1 is a schematic top view of a vehicle front portion of a fuel cell vehicle equipped with a fuel cell module as one embodiment of the present invention.
FIG. 2 is a perspective view showing a state in which a wiring 42 is bolted to an end plate 30.
FIG. 3 is an explanatory diagram showing an electrical configuration of a leakage detector 40 together with a fuel cell stack 24 and an ECU 54.
[Explanation of symbols]
20 fuel cell module 22 fuel cell stack case 24 fuel cell stack 25 single cell 26 first stack 28 second stack 30 end plate 30a wall surface 32 end plates 34 and 36 electrodes 38 Terminal 40: Electric leakage detector 42 ... Wiring 42a ... End 44 ... Mounting bracket 46 ... Bolt 50 ... Injection port 52 ... Discharge port 54 ... ECU
61, 62 ... resistor 63 ... voltage detection circuit 64 ... warning output circuit 71, 72 ... relay

Claims (5)

In a fuel cell module including a fuel cell that supplies driving power of a vehicle and a leakage detector that detects leakage from the fuel cell,
A case is provided to cover the fuel cell,
A fuel cell module, wherein the leakage detector is provided in the case. The fuel cell module according to claim 1, wherein
The fuel cell includes a stack of unit cells supported at both ends in the stacking direction by end plates having high rigidity,
The leakage detector is a fuel cell module disposed on the end plate. In a fuel cell module including a fuel cell that supplies driving power of a vehicle and a leakage detector that detects leakage from the fuel cell,
The fuel cell includes a stack of unit cells supported at both ends in the stacking direction by end plates having high rigidity,
The fuel cell module, wherein the leakage detector is disposed on the end plate. The fuel cell module according to claim 2 or 3, wherein
The fuel cell is configured to charge the end plate to an intermediate potential,
The fuel cell module according to claim 1, wherein the electric leakage detector directly connects an electric wiring to the end plate, and draws an intermediate potential of the fuel cell through the electric wiring. A fuel cell vehicle equipped with the fuel cell module according to claim 2,
A fuel cell vehicle, wherein the fuel cell module is mounted so that a stacking direction of the fuel cells is oriented in a lateral direction of the vehicle.

Images