JP2003297377A - On-vehicle type fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stably operable on-vehicle type fuel cell by protecting the fuel cell from vibration or impact when it is mounted on a vehicle and preventing deviation or distortion between each cell composing a laminated body. <P>SOLUTION: The on-vehicle type fuel cell has the laminated body 13 of laminating a plurality of cells 11, and a pair of fastening members 14 and 15 positioned in both ends of the cells in a laminating direction to hold the laminated body. It is characterized by that it has a case body 19 covering the laminated body and the fastening member, and a first elastic body 20 connected the case body with at least one of the fastening members. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a vehicle-mounted fuel cell.

[0002]

2. Description of the Related Art One of the fields of application of fuel cells is the power source of vehicles. When a fuel cell is installed in a vehicle and used, the vehicle starts, stops, shakes the vehicle body while running,
Repeated load and shock load are applied due to vibration. If the measures for eliminating these loads, that is, the so-called vibration resistance, are insufficient, the components of the fuel cell may be damaged.

As a measure against vibration resistance, a reinforcing frame is constructed around the fuel cell installed on the floor of the vehicle, and a support for supporting the upper clamping plate of the fuel cell is provided on the top of the reinforcing frame through a support tool. The structure is known (Japanese Patent Laid-Open No. 5-821).
No. 57).

[0004]

However, in the conventional support structure, the fuel cell does not rock relative to the vehicle body, but vibrations and impacts from the outside of the vehicle body are easily transmitted directly to the fuel cell.

A fuel cell generally has a laminated body in which a plurality of cells are laminated, and when subjected to vibration or impact, there is a risk that misalignment or distortion will occur between the cells constituting the laminated body.
This deviation causes an increase in electrical contact resistance of the fuel cell and a decrease in output.

In order to prevent the displacement and distortion between the cells constituting the laminated body, the tightening force for the laminated body may be increased. However, if an excessive tightening force that exceeds the force that can be tolerated by the components such as the cells forming the laminated body is applied, the components may be damaged. Further, high-frequency vibration may damage a component made of a brittle material.

The present invention has been made in view of the problems associated with the above technique, and when a fuel cell is mounted on a vehicle, the fuel cell can be protected from vibrations and impacts, and each cell constituting the laminated body can be protected. An object of the present invention is to provide a vehicle-mounted fuel cell capable of preventing a gap and a strain and stably operating.

[0008]

The objects of the present invention are achieved by the following means.

A vehicle-mounted fuel cell having a laminated body in which a plurality of cells are laminated, and a pair of fastening members which are located at both ends in the laminating direction of the cells and sandwich the laminated body,
A case body that covers the laminated body and the tightening member,
A vehicle-mounted fuel cell, comprising: a first elastic body that connects at least one of the case body and the tightening member.

[0010]

The present invention described above has the following effects.

When a fuel cell is mounted on a vehicle, it is possible to prevent displacement and strain between the cells constituting the laminated body due to various vibrations and impacts applied from the vehicle body, and the fuel cell can be stably stabilized. Can be operated.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an outline of a vehicle-mounted fuel cell according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing an exploded state of the laminated structure of the vehicle-mounted fuel cell according to the first embodiment.

There are several types of fuel cells,
In the first embodiment, a flat plate polymer electrolyte fuel cell (PEFC) was used.

The fuel cell 10 of the first embodiment has a cell 1
A laminated body 13 in which a plurality of 1 and separators 12 are alternately laminated.
And a first tightening plate 14 and a second tightening plate 14 which are located at both ends of the cell 11 in the stacking direction to uniformly press the stack 13 together.
Tightening plate 15 (corresponding to a pair of tightening members).

The cell 11 is a power generation unit of the fuel cell.
Since the output of one cell 11 is insufficient, a stacked body 13 in which a plurality of cells 11 are stacked is used to increase the output voltage. When the cells 11 are stacked, the separator 12 is used as a member for electrically connecting the cells 11 to each other.
The separator 12 also has a role of separating hydrogen and air supplied between the cells 11.

A fastening stud 16 is used to fasten between the first fastening plate 14 and the second fastening plate 15. Through holes 21 through which the fastening studs 16 are inserted are formed in the stacking direction of the cells 11. The first tightening plate 14 and the second tightening plate 15 are provided with tightening holes 22 communicating with the through holes 21 of the laminated body 13 and inserting the tightening studs 16. The first tightening plate 14 and the second tightening plate 15 are connected to each other through the through holes 21 and the tightening holes 22 through the tightening studs 16, and the laminated body 13 is pressed from above and below.

The fuel cell 10 has a manifold. The manifold is a means for supplying and discharging gas to and from each cell, and further supplying and discharging cooling water. The manifold type is roughly classified into an external type and an internal type.
In this embodiment, the manifold 17 is provided inside the laminated body 13.
An internal type manifold having The cells 11 and the separator 12 are provided with manifold grooves 23 through which various fluids flow.

Here, the assembly having the laminated body 13, the fastening plate and the manifold 17 is referred to as a cell stack 18.

The fuel cell 10 further comprises a cell stack 1
8 includes a reinforcing frame 19 (corresponding to a case body) and a spring member 20 (corresponding to a first elastic body) that is an elastic body that connects the reinforcing frame 19 and the tightening plates 14 and 15. is doing. The spring member 20 is a compression spring. Reinforcing frame 19
Is at least partially fixed to the vehicle, and in the first embodiment, is tightly connected to the floor of the vehicle. The lower part of FIG. 1 corresponds to the portion tightly connected to the floor of the vehicle.

At least one of the tightening plates 14 and 15 is connected to the reinforcing frame 19 via a spring member 20. The place to connect is the first tightening plate 14 in FIG.
And between the upper part of the reinforcing frame 19 is shown. The second tightening plate 15 and the lower portion of the reinforcing frame 19 or both of the tightening plates 14 and 15 may be connected to the reinforcing frame 19 via the spring member 20. The spring member 20 is not limited to a compression spring, and is made of a flexible resin such as a leaf spring or rubber.
Various elastic bodies can be used.

FIG. 3 shows a solid polymer electrolyte fuel cell (P
It is a schematic sectional drawing of EFC).

The PEFC used in the first embodiment will be outlined. Since PEFC can generate power at a temperature of about 70 ° C, it can be expected to be applied to a distributed power supply for small-scale power generation and a power supply for electric vehicles.

As shown in FIG. 3, in PEFC, a catalytic reaction layer 32 mainly composed of carbon powder carrying a platinum-based metal catalyst is arranged on both sides of a polymer electrolyte membrane 31 which selectively transports hydrogen ions. There is. A diffusion layer 33 having both gas permeability and conductivity is closely arranged on the outer surface. Further, in order to prevent hydrogen and air from leaking to the outside and mixing with each other, a sealing material 35 is placed around the electrodes with a polymer electrolyte membrane 31 interposed therebetween to seal a gap with the separator 12. The structure is adopted. Since the separator 12 is impermeable to hydrogen and needs to have conductivity and corrosion resistance, it is generally made of carbon. The cell 11 is formed by the electrode 34 including the catalytic reaction layer 32 and the diffusion layer 33, the electrolyte membrane 31, and the sealing material 35.

A conductive separator 12 is disposed outside the cell 11 to mechanically fix the cell 11 and to electrically connect adjacent cells 11 to each other in series. In the portion of the separator 12 that is in contact with the electrode 34, a gas flow path 38 is formed for supplying a reaction gas to the electrode and carrying away the gas generated by the reaction, moisture or excess gas. Further, inside the separator 12, a cooling water passage 39 for circulating cooling water for keeping the battery temperature constant is provided.

As described above, according to the structure of the first embodiment, the fuel cell 10 does not rock relative to the vehicle because the reinforcing frame 19 is tightly connected to the vehicle. The cell stack 18 is connected to the reinforcing frame 19 by the spring member 20. Even if vibrations caused by starting, stopping, and traveling of the vehicle are applied to the entire fuel cell 10, the cell stack 18 is directly vibrated and impacted. Is not transmitted, and only the force absorbed and relieved by the spring member 20 is transmitted.

Vibration and impact of the cells 11 in the stacking direction may cause a change in the tightening force between the cells 11.
Further, the elongation in the stacking direction due to the vibration and the shock may deteriorate the gas sealing property, increase the electrical contact resistance in the stack 13, decrease the output, and deviate the heat distribution, which may damage the entire cell stack 18. There is. In the first embodiment, since the spring member 20 supports the cell stack 18, it is possible to reduce vibration and shock to a level at which the cell stack 18 is not damaged.

Further, since the spring member 20 presses the cell stack 18 while displacing the spring member 20, the change in the tightening force on the cell stack 18 can be reduced. Therefore, the expansion and displacement of the cell stack 18 can be suppressed.

Since the change in the tightening force when vibration or impact is applied can be reduced, it is not necessary to perform excessive tightening in preparation for the case where the tightening force becomes small.
Strain of the tightening plates 14 and 15 due to excessive tightening,
Breakage of the connection between the tightening plates 14 and 15 and the tightening stud 16, abnormal crush of the sealing material, separator 12
It is possible to prevent gas leakage and damage to the cell stack 18, such as damage to the cell stack.

As described above, according to the first embodiment, when the fuel cell 10 is mounted on a vehicle, various vibrations and impacts applied from the vehicle body may cause misalignment between the cells 11 forming the laminate 13. It is possible to prevent distortion,
The fuel cell 10 can be operated safely and stably.

(Modification 1 of the first embodiment) Modification 1
Seals the reinforcing frame 19 and fills the inside of the reinforcing frame 19 with an insulating liquid. The liquid also includes a gel-like substance. Although it is not impossible to use a conductive liquid, the cell stack 18 needs to be processed so as not to leak. The boiling point of the liquid to be filled is preferably equal to or higher than the operating temperature of PEFC for safety.

The liquid filled in the reinforcing frame 19 further attenuates the vibration dampened by the spring member 20 and transmits it to the cell stack 18. Therefore, it is possible to further alleviate the vibration and shock as compared with the case of only the first embodiment.

(Modification 2 of the First Embodiment) Cell 11
Operates at a temperature higher than room temperature. In order to maintain the temperature environment inside the vehicle in a comfortable environment for humans, it is preferable that heat from the cells 11 is not output to the outside of the reinforcing frame 19 as much as possible. In Modification Example 2, the inside of the reinforcing frame 19 is hermetically sealed, and the pressure inside the reinforcing frame 19 is made lower than the atmospheric pressure.

With this structure, the cell 11 by convection is used.
It is possible to suppress the heat transfer from the vehicle and suppress the release of heat from the reinforcing frame 19 into the vehicle. In addition to the effect of mitigating vibration and shock in the case of only the first embodiment, it is possible to suppress the temperature rise inside the vehicle and reduce the load on the air conditioning equipment. In addition, the amount of heat insulating material used can be reduced, and the total weight of the fuel cell can be reduced.

(Second Embodiment) FIG. 4 is a perspective view showing the outline of a vehicle-mounted fuel cell according to the second embodiment.

The second embodiment is intended to prevent the stacked cells 11 and the separators 12 from shifting when a force is constantly applied in a direction orthogonal to the stacking direction of the cells 11. In addition to the first embodiment, the laminated body 1
Among the three side surfaces, a reinforcing member 41 supporting a side surface in a direction orthogonal to the stacking direction of the cells 11, for example, a side surface facing the floor surface of the vehicle, and between the reinforcing frame 19 and the reinforcing member 41 from the vehicle. It has a spring member 42 for removing vibration and impact. Similar to the first embodiment, the cell stack 18 is connected to the reinforcing frame 19 by the spring member 20 also in the stacking direction of the cells 11.

Although FIG. 4 shows that the vehicle is installed horizontally with respect to the floor of the vehicle, the same applies when the vehicle is installed with an inclination.

According to the structure of the second embodiment, in addition to the structure of the first embodiment, it is possible to prevent the cells 11 and the separators 12 constituting the laminated body 13 from slipping, and to prevent the cells 11 from being excessively added to the cell stack 18. It is possible to prevent a strong tightening force.

(Third Embodiment) FIG. 5 is a perspective view showing the outline of a vehicle-mounted fuel cell according to the third embodiment.

In the case of an automobile, in its basic motions such as running, turning, and stopping, movements in all directions including front and rear, left and right, and up and down always occur. Regardless of how the fuel cell 10 is arranged, a force perpendicular to the stacking direction of the cells 11, that is, a force in the direction in which the cells 11 and the separator 12 cause slippage is generated.

A factor that determines the tightening force of the laminated body 13 is a force for preventing the constituent members such as the cells 11 and the separators 12 from being displaced when a vibration or a shock is applied from a direction orthogonal to the laminating direction of the cells. Can be mentioned. By passing the fastening studs 16 through the laminate 13, large deviations can be prevented. However, there is a gap between the tightening stud 16 and the through hole 21. In the fuel cell 10, even a slight deviation of each member constituting the laminated body 13 causes a decrease in gas sealability and an increase in electrical contact resistance, so the tightening force is strengthened to prevent the deviation. However, excessive tightening may cause distortion of the tightening plates 14 and 15, breakage of the connection between the tightening plates 14 and 15 and the tightening stud 16, abnormal crushing of the sealing material, damage to the cells 11 and the separator 12, and the like. .

Therefore, in the third embodiment, in addition to the connection of the laminated body 13 by the spring member 20 from the laminating direction of the cell 11, the reinforcing plate 51 is provided on the side surface of the cell 11 in the direction orthogonal to the laminating direction and the reinforcing plate 51. The spring member 52 connects the frame 19 and the reinforcing plate 51.

In the third embodiment, by providing the reinforcing plate 51 on the side surface of the cell stack 18 and designing the side surface by the spring member 52 as well, it is not necessary to rely on the clamping force in the stacking direction for the lateral displacement. . Therefore, the tightening force can be further reduced, and the stress on each member due to the tightening can be relieved. Also,
Since the elastic constant of the spring member 20 of the first embodiment affects the force for tightening the cell stack 18, it must be designed in consideration of prevention of deviation. However, in the third embodiment, it is possible to set with a high degree of freedom without considering the function of preventing deviation, and it is possible to further improve vibration resistance and impact resistance.

FIG. 6 is a perspective view showing the outline of the external manifold type.

In general, the external manifold type 60 has a fluid supply / discharge port 62 on the end face of the laminated body 61, and the external manifold 63 is attached to this end face. Various fluids are supplied and discharged from a pipe 64 attached to the manifold 63.

Although the first to third embodiments use the internal manifold type, each embodiment can be applied to the external manifold type as well as the internal type.

(Fourth Embodiment) The present invention also deals with a solid oxide electrolyte fuel cell (SOFC). SOFC is another type of fuel cell, such as PE
It has characteristics of higher power generation efficiency and higher exhaust heat temperature than FC, and it can be expected to construct an efficient power generation system.

The SOFC structure is generally a flat plate type as in the PEFC. However, the operating temperature is 800 ℃ ~ 100
Since the temperature is as high as about 0 ° C., the cell 11 has a yttria-stabilized zirconia (Y ₂ O ₃ Stabilized Zr).
O ₂ ), scandia-stabilized zirconia (Sc ₂ O ₃ St
abilized ZrO ₂₎ ceramic-based material or the like, a nickel - composed of such cermet based material. For the separator 12, a lanthanum chromite ceramic material, a heat-resistant metal material, or the like is used as a material having a good conductive function. In an SOFC that mainly uses a ceramic material whose constituent material is more brittle than a metal material, there is a possibility that the constituent member may be damaged by high-frequency vibration during vehicle running.

FIG. 7 is a diagram showing an opening portion of an SOFC having a honeycomb structure.

FIG. 8 shows a honeycomb SOFC cell.

FIG. 9 is a perspective view of a laminate in which honeycomb SOFC cells are laminated.

The structure of SOFC is not limited to the flat plate type, and there is a honeycomb type. When the honeycomb type SOFC is outlined, a fuel electrode (Ni-YSZ) is provided on the inner wall of a honeycomb structure made of yttria-stabilized zirconia (YSZ) in which a large number of honeycomb channels 71 having a square cross section are vertically and horizontally arranged. Fuel electrode channel array 72
And the air electrode (La _1-x S on the inner wall surface 75 of the honeycomb channel).
r _x MnO ₃ ) provided on the air electrode channel row 73, and an interconnector (LaCrO) on the inner wall surface of the honeycomb channel.
₃ ) and the interconnector channel row 74 provided with ₃ ) are sequentially laminated.

Opened faces 81, 82 of the honeycomb structure
Further, gas manifolds 83 and 84 are connected to an electrode 85 for extracting an output on a surface parallel to the column direction.
In order to increase the output, as shown in FIG. 9, a plurality of box-shaped cells 80 are stacked to form a cell stack 90.

Even in the SOFC, vibration can be reduced by the same structure as in the first to third embodiments described for the PEFC.

However, the SOFC cell 11 becomes extremely hot and rises to, for example, about 800 to 1000 ° C. An elastic body made of resin or ordinary metal may not maintain its shape or elastic force during operation. So SOFC
In the fuel cell using, the spring members 20, 32, 4
For 2, it is preferable to use a ceramic spring having excellent heat resistance.

The cell stack 9 in which the honeycomb-shaped cells 81 are stacked is not limited to the case where the flat-plate type cells 11 are stacked.
Even in the case of 0, the same effect can be obtained by implementing the cell stack 18 instead.

The spring member can block high-frequency vibrations during traveling, which can prevent the risk of damage and the deterioration of the gas seal.

(Modification of Fourth Embodiment) Since the vibration from the vehicle is directly transmitted to the reinforcing frame 19, it is preferable to use a metal material resistant to vibration. It is difficult to select a metal material with high strength while withstanding the operating temperature of SOFC.
It is also expensive. Therefore, it is necessary to reduce the heat transmitted to the reinforcing frame 19.

Therefore, as described in the modified example 2 of the first embodiment, the inside of the reinforcing frame 19 is sealed and the pressure inside the reinforcing frame 19 is made lower than the atmospheric pressure.

With this structure, the heat transmitted from the cells 11 and 80 to the reinforcing frame 19 can be suppressed. It is possible to use a material having a low heat resistance temperature, and it is possible to supply an inexpensive vehicle-mounted fuel cell. Further, the temperature rise inside the vehicle can be suppressed, and the load on the air conditioner can be reduced. It is also possible to reduce the amount of heat-resistant material used.

In PEFC, Modification 1 of the first embodiment
In the above, an example was described in which the inside of the reinforcing frame was sealed and filled with liquid. However, since the operating temperature of the SOFC cell is extremely high, it is desirable to avoid filling the inside of the reinforcing frame with liquid from the viewpoint of the boiling point.

In the first to fourth embodiments, PEFC is used.
Although the SOFC fuel cell has been taken up, each embodiment of the present invention can be applied to other types of fuel cells as long as they are of a laminated type.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outline of a vehicle-mounted fuel cell according to a first embodiment.

FIG. 2 is a perspective view showing an exploded state of the laminated structure of the vehicle-mounted fuel cell according to the first embodiment.

FIG. 3 is a schematic sectional view of a solid polymer electrolyte fuel cell (PEFC).

FIG. 4 is a perspective view showing an outline of a vehicle-mounted fuel cell according to a second embodiment.

FIG. 5 is a perspective view showing an outline of a vehicle-mounted fuel cell according to a third embodiment.

FIG. 6 is a perspective view showing an outline of an external manifold type.

FIG. 7 is a view showing an opening portion of an SOFC having a honeycomb structure.

FIG. 8 is a diagram showing a cell of a honeycomb SOFC.

FIG. 9 is a perspective view of a laminated body in which cells of a honeycomb type SOFC are laminated.

[Explanation of symbols]

10 ... Vehicle-mounted fuel cell 11, 80 ... cell 13 ... Laminated body 14 ... First tightening plate (tightening member) 15 ... Second tightening plate (tightening member) 19 ... Reinforcing frame (case body) 20 ... Spring member (first elastic body) 41, 51 ... Reinforcing member 42, 52 ... Spring member (second elastic body)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Keiko Kushibiki             Nissan, Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan             Inside the automobile corporation (72) Inventor Naoki Hara             Nissan, Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan             Inside the automobile corporation F term (reference) 5H026 AA06 CC03 CC08 CX08 CX10

Claims (6)

[Claims] 1. A vehicle-mounted fuel cell, comprising: a laminated body in which a plurality of cells are laminated, and a pair of tightening members which are located at both ends of the cell in the laminating direction and which sandwich the laminated body, wherein the laminated body and the A vehicle-mounted fuel cell, comprising: a case body that covers the fastening member; and a first elastic body that connects at least one of the case body and the fastening member. 2. A reinforcing member that supports at least one side surface of a side surface of the stacked body in a direction orthogonal to a stacking direction of the cells, and a second elastic member that connects the case body and the reinforcing member. The vehicle-mounted fuel cell according to claim 1, having a body. 3. The vehicle-mounted fuel cell according to claim 1, wherein the case body is sealed, and the pressure inside the case body is lower than atmospheric pressure. 4. The cell is a solid polymer electrolyte fuel cell, the case body is sealed, and the inside of the case body is filled with an insulating liquid. The vehicle-mounted fuel cell according to item 1. 5. The vehicle-mounted fuel cell according to claim 1, wherein the cell is a solid oxide electrolyte fuel cell, and the first elastic body is a ceramic spring. 6. The vehicle-mounted type according to claim 2, wherein the cell is a solid oxide electrolyte fuel cell, and the first elastic body and the second elastic body are ceramic springs. Fuel cell.