JP2006221854A - Fuel cell for movable body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily conduct the check of a fuel cell stack and maintenance work such as the exchange of components in a fuel cell for a movable body mounted to the movable body. <P>SOLUTION: A stack case housing the fuel cell stack 40 is constituted by joining a first case 20 and a second case 10. The fuel cell stack 40 is fixed to the fixing surface of the first case 20 with the stacking direction horizontal in relation to the perpendicular line of the fixing surface. At least one region facing the wall surface of an end 44 in the stacking direction of the fuel cell stack 40, in the joining region of the first case 20 to the second case 10 is positioned between the fixed surface of the first case 20 and the wall surface of the end 44. When the first case 20 is separated from the second case 10, at least a part of the end 44 of the fuel cell stack 40 is exposed to the outside of the first case 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel cell for a mobile body mounted on a mobile body such as an electric vehicle, and more particularly to a structure of a stack case that houses a fuel cell stack.

  2. Description of the Related Art A fuel cell stack that generates power using hydrogen as a fuel is known as a power source for driving a moving body such as an electric vehicle. When a fuel cell stack is mounted on a moving body, it is required to ensure internal heat retaining properties, high voltage stability, electromagnetic shielding properties, and the like, and also to ensure rigidity against vibration and torsion input from the moving body. It must also be able to withstand harsh environmental conditions such as stepping stones, mud and water. For this reason, the fuel cell stack is usually mounted on the moving body in a state of being housed in the stack case.

Conventionally, various structures have been proposed for the structure of the stack case. As a stack case used for a fuel cell for a moving body, a bath tub type case as disclosed in Patent Document 1 is generally used. A fuel cell stack is placed horizontally in a bath-tubular case, that is, the cell stacking direction is placed beside the perpendicular to the fixed surface, and the opening at the top of the case is closed with a cover. In the fuel cell for moving bodies, the fuel cell stack in the stack case is generally placed horizontally, but in a stationary fuel cell for a power plant or the like, for example, as disclosed in Patent Document 2, Vertical placement is also common in which the cell stacking direction is set perpendicular to the fixed surface.
JP 2004-127787 A Japanese Patent Laid-Open No. 7-282834

  By the way, in the fuel cell for moving bodies, the cells, pipes, electrical parts, etc. constituting the fuel cell stack are often inspected regularly or as necessary. If there are any problems as a result of the inspection, it is necessary to replace the parts. However, in a commonly used bath bowl type case, there is a high possibility that parts cannot be easily inspected or replaced by simply removing the cover. Parts that require inspection and replacement are gathered at both ends of the fuel cell stack, but there are often no gaps between the ends of the fuel cell stack placed sideways and the side walls of the case. This is because the replacement parts cannot be touched as well as the parts are removed.

  For this reason, in the conventional mobile fuel cell, the fuel cell stack is lowered from the mobile body together with the stack case, the fuel cell stack is extracted from the stack case, and parts are replaced. However, such a method requires a great amount of time and labor every time a part is inspected or replaced. In addition, when the fuel cell stack is placed vertically as disclosed in Patent Document 2, it is easy to inspect and replace the components arranged at the upper end of the fuel cell stack, but the fuel cell stack is arranged at the lower end. The inspection and replacement of parts becomes difficult.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a mobile fuel cell that can easily perform maintenance work such as inspection of the fuel cell stack and replacement of its components. And

In order to achieve the above object, a first invention includes a fuel cell stack configured by stacking a plurality of cells, and a stack case formed by joining the first case and the second case. In a mobile fuel cell,
The first case has a fixed surface to which the fuel cell stack is fixed;
The fuel cell stack is fixed in a state in which the stacking direction is lateral to the perpendicular of the fixed surface,
At least a part of the joining portion between the first case and the second case and facing the end wall surface in the stacking direction of the fuel cell stack extends from the fixed surface to the inside of the end wall surface. It is characterized by being provided so that it may be located between.

  According to a second invention, in the first invention, the first case is fixed to a moving body.

  A third invention is characterized in that, in the first or second invention, the first case is formed in a plate shape.

  According to a fourth invention, in the third invention, the first case is provided with a structure for reinforcing rigidity.

  According to a fifth invention, in the fourth invention, the structure for reinforcing the rigidity is a plurality of ribs formed in the first case.

In a sixth aspect based on the fifth aspect, the stack case is mounted on the movable body with the first case on the lower side and the second case on the upper side.
The first case is provided with a liquid reservoir for storing liquid generated in the stack case,
The rib also serves as a guide for guiding the liquid dropped on the first case to the liquid reservoir.

  According to a seventh aspect, in the sixth aspect, the first case is provided with a discharge hole for discharging the liquid accumulated in the liquid reservoir to the outside.

  According to the first invention, when the first case and the second case are separated, at least a part of the end wall surface in the stacking direction of the fuel cell stack is exposed to the outside of the first case. Therefore, it is possible to easily inspect and replace components arranged at the end of the fuel cell stack in the stacking direction.

  According to the second invention, since the first case to which the fuel cell stack is fixed is fixed to the moving body, the fuel cell stack is mounted on the moving body simply by removing the second case. Inspection and parts replacement can be performed as is.

  According to the third invention, since the first case is plate-shaped, it can be easily processed, and the end of the fuel cell stack can be exposed to the maximum.

  Further, according to the fourth invention, it is possible to prevent the fuel cell stack from being twisted due to insufficient rigidity of the first case. In particular, according to the fifth invention, the rib can be easily formed by press molding, so that the rigidity of the first case can be easily reinforced.

  According to the sixth aspect of the invention, since the reinforcing rib is also used as a guide for guiding the liquid generated in the stack case to the liquid reservoir, the liquid generated in the stack case is scattered on the first case. This can be prevented. In particular, according to the seventh aspect, since the liquid accumulated in the liquid reservoir can be discharged out of the stack case through the discharge hole, the liquid can be prevented from overflowing from the liquid reservoir.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 4.
FIG. 1 is a side sectional view showing a configuration of a mobile fuel cell as an embodiment of the present invention. In this moving body fuel cell, the stack case that houses the fuel cell stack 40 is composed of two pieces, a hat-type upper case 10 and a plate-type lower case 20. On the lower case 20, the fuel cell stack 40 is arranged in a state where the cell stacking direction is transverse to the perpendicular direction, and the upper case 10 is covered so as to cover the fuel cell stack 40 from above. Both the upper case 10 and the lower case 20 are coated at least on the inner surface with an insulating material (for example, polyethylene). A gasket 50 is interposed between the flange of the upper case 10 and the edge of the lower case 20 to prevent water and mud from entering the stack case. The hat shape of the upper case 10 can be formed by press deep drawing such as aluminum.

  The fuel cell stack 40 is disposed on the lower case 20 via an insulator mount 60. End plates 44 are attached to both ends of the fuel cell stack 40 in the cell stacking direction. The insulator mount 60 is sandwiched between the end plate 44 and the upper surface of the lower case 20. A plurality of pipes 46 are connected to the wall surface of the end plate 44 of the fuel cell stack 40 for supplying and discharging refrigerant liquid and reaction gas. The pipe 46 extends through the lower case 20 to the outside of the stack case. A portion of the lower case 20 through which the pipe 46 passes is sealed with a gasket or the like.

  The lower case 20 is attached to a vehicle frame (or subframe) 32 via a body member 30. The body member 30 also serves as a reinforcing member for reinforcing the rigidity of the lower case 20. The body member 30 and the vehicle frame 32 are welded, and the lower case 20 and the body member 30 are fastened by bolts 34. The bolt 34 extends through the insulator mount 60 to the end plate 44 of the fuel cell stack 40, and fastens the end plate 44 and the insulator mount 60 to the lower case 20.

  The upper case 10 and the lower case 20 are fastened by a detachable fastener such as a bolt. When inspecting the fuel cell stack 40 or replacing parts, the upper case 10 can be removed from the lower case 20 to expose both ends and the upper surface of the fuel cell stack 40 in the stacking direction. The pipe 46 and the like are connected to the end wall surface in the stacking direction of the fuel cell stack 40 as described above, and the cell monitor 42 indicating the power generation status of the cell is mounted on the upper surface. By exposing these maintenance parts, it becomes possible to perform inspection work and parts replacement work with the fuel cell stack 40 mounted on the vehicle.

  2 is a top view of the mobile fuel cell with the upper case 10 removed, and FIG. 3 is a top view of the mobile fuel cell with the fuel cell stack 40 removed, that is, 3 is a top view of the lower case 20. FIG. In FIG. 3, a through hole through which the pipe 46 passes is omitted. On the upper surface of the lower case 20, as shown in FIG. 3, a plurality of rows of grooves 22 are formed vertically and horizontally in a lattice shape. FIG. 4 is a cross-sectional view taken along the line XX of FIG. 3. As shown in FIG. 4, ribs 26 are formed along the grooves 22 on the lower surface of the lower case 20. By forming the ribs 26, the thickness of the lower case 20 can be made substantially constant, stress concentration in the groove 22 can be relaxed, and the bending strength of the lower case 20 can be improved. Further, a concave portion (a liquid reservoir portion) 24 that is circular and deeper than the groove 22 is formed in the center portion of the lower case 20, and several grooves 22 in vertical and horizontal directions communicate with the concave portion 24. . In addition, the groove | channel 22, the rib 26, and the recessed part 24 can be shape | molded by the casting containing aluminum and magnesium die-casting, the press molding of a metal plate material, etc.

  During the operation of the fuel cell stack 40, the temperature inside the stack case becomes high, so that condensation may occur on the inner surface of the stack case. The condensed water drops on the lower case 20 which is the bottom surface and is collected by a groove 22 formed on the upper surface of the lower case 20. The condensed water collected in the groove 22 moves in the groove 22 due to vibration during traveling of the vehicle and G in the planar direction, and eventually flows into the central recess 24. The recess 24 is formed with a discharge hole 24a at the center thereof. The condensed water that has flowed into the recess 24 is discharged out of the stack case through the discharge hole 24a.

  According to the mobile fuel cell having the above-described configuration, not only the upper surface of the fuel cell stack 40 but also both ends in the stacking direction can be completely exposed by simply removing the upper case 10 from the lower case 20. In the case of a bath tub type stack case, maintenance work such as inspection and replacement of parts is not possible if the fuel cell stack is mounted on the vehicle because the gap between the side wall of the case and both ends in the stacking direction of the fuel cell stack is not accessible. However, in the case of the structure of the present embodiment, since all the maintenance parts are exposed, the maintenance work can be performed while the fuel cell stack 40 is mounted on the vehicle. Therefore, according to the mobile fuel cell according to the present embodiment, labor and time spent for maintenance can be significantly reduced.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the following modifications may be made.

  In the above embodiment, the lower case 20 is formed in a plate shape. However, if at least a part of the end wall surface in the stacking direction of the fuel cell stack 40 is exposed, that is, the lower case 20 and the upper case 10 are joined. If at least a part of the portion is located between the fixed surface to which the fuel cell stack 40 is fixed and the end wall surface of the fuel cell stack 40, the lower case 20 has a deep box shape. May be formed. Even when the end wall surface of the fuel cell stack 40 is not completely exposed, if at least a part (preferably half or more) of the fuel cell stack 40 is exposed, the maintenance work can be performed by putting a hand there. .

  In the above embodiment, the pipe 46 passes through the lower case 20, but the pipe 46 may pass through the upper case 10. In this case, it is desirable that the pipe 46 is formed by connecting the inner part and the outer part of the stack case with a flange or the like so that the pipe 46 can be separated inside and outside the stack case when the upper case 10 is removed. Alternatively, the upper case 10 may be moved along the pipe 46 when a grommet is attached to the through hole of the upper case 10 and the upper case 10 is removed.

  Further, in the above embodiment, the case on the side for fixing the fuel cell stack (the lower case in the above embodiment) is fixed to the vehicle frame, but the case on the side covering the fuel cell stack (in the above embodiment, the upper case) The case) may be fixed to the vehicle frame. Further, contrary to the above embodiment, the lower case may be formed in a hat shape, the upper case may be formed in a plate shape, and the fuel cell stack may be fixed to the lower surface of the upper case. Even in such a configuration, the end of the fuel cell stack can be exposed by separating the upper case and the lower case. In this case, either the upper case or the lower case may be fixed to the vehicle frame.

It is side surface sectional drawing which shows the structure of the fuel cell for moving bodies as embodiment of this invention. FIG. 2 is a top view of the moving body fuel cell of FIG. 1 with an upper case removed. FIG. 2 is a top view of the moving body fuel cell of FIG. 1 with an upper case and a fuel cell stack removed. It is XX sectional drawing of FIG. 3 which shows the cross-sectional shape of a lower case.

Explanation of symbols

10 Upper Case 20 Lower Case 22 Groove 24 Recess 24a Discharge Hole 26 Rib 30 Body Member 32 Vehicle Frame 34 Bolt 40 Fuel Cell Stack 42 Cell Monitor 44 End Plate 46 Pipe 50 Gasket 60 Insulator Mount

Claims (7)

In a mobile fuel cell comprising a fuel cell stack configured by stacking a plurality of cells, and a stack case formed by joining a first case and a second case,
The first case has a fixed surface to which the fuel cell stack is fixed;
The fuel cell stack is fixed in a state in which the stacking direction is lateral to the perpendicular of the fixed surface,
At least a part of the joining portion between the first case and the second case and facing the end wall surface in the stacking direction of the fuel cell stack extends from the fixed surface to the inside of the end wall surface. A fuel cell for a moving body, wherein the fuel cell is provided between the two.   The mobile fuel cell according to claim 1, wherein the first case is fixed to the mobile body.   The mobile fuel cell according to claim 1 or 2, wherein the first case is formed in a plate shape.   4. The mobile fuel cell according to claim 3, wherein the first case is provided with a structure for reinforcing rigidity.   5. The mobile fuel cell according to claim 4, wherein the structure for reinforcing rigidity is a plurality of ribs formed in the first case. The stack case is mounted on a movable body with the first case on the lower side and the second case on the upper side,
The first case is provided with a liquid reservoir for storing liquid generated in the stack case,
6. The mobile fuel cell according to claim 5, wherein the rib also serves as a guide for guiding the liquid dropped on the first case to the liquid reservoir. The mobile fuel cell according to claim 6, wherein the first case is provided with a discharge hole for discharging the liquid accumulated in the liquid reservoir to the outside.

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