JPH0547406A - Fuel cell - Google Patents

Abstract

PURPOSE:To make a fuel cell compact by arranging stacks into a plurality of groups in parallel separately and connecting the upper or lower end plates each other. CONSTITUTION:The lower parts of stacks 1, 1 set separately in right and left parallel are supported by one common integrated lower end plate 3 and separate upper part end plates 4, 4 are brought into contact with the upper parts and moreover, they are fastened and fixed by bolts at four corners while an X-shape fastening bar 5 is flatly put in the outside of the plate 3 and an X-shape fastening bar 6 and a spring 8 are put in the same way in the outside of the plates 4. The upper end of the spring 8 is joined with a spring seat 6a and the center periphery of the plates 4 are pressed, so that the electricity generating part in the inside can be fastened uniformly in all and the height of the whole body of the stacks can be made low while keeping the length of the spring sufficiently long and the size can be made compact by overlapping the bar 6 and the spring 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell which is compact and can be stably supported even when mounted on a moving body or the like.

[0002]

2. Description of the Related Art Generally, a fuel cell is composed of a stack in which a large number of unit cells are stacked in multiple stages. When trying to obtain a high power generation voltage from a fuel cell having such a configuration, it is sufficient to increase the number of stack stages, but as the number of stack stages increases, the stack height in the vertical direction increases and the center of gravity moves upward. It moves and the rigidity against bending load decreases. Therefore, when this fuel cell is installed in a vehicle that vibrates or swings, the support is likely to be unstable, and the bending load causes an unbalanced load on the boundary between the unit cells, resulting in a seal between the unit cells. However, there is a problem that the property is likely to deteriorate.

As a result of studying these solutions, the inventor of the present invention can reduce the center of gravity per stack by improving the rigidity against bending load by arranging the stacks separately. I found that I could solve the problem. However, in the fuel cell, the stack components repeatedly undergo thermal expansion and thermal contraction during operation and shutdown, so it is necessary to have a structure that can absorb the difference in fluctuations. There are special circumstances that are difficult to do.

Therefore, when the fuel cell is mounted on a vehicle or the like, even if the stack is divided into a plurality of stacks as described above, if each stack has a certain height or more, the stack is vibrated or rocked to cause stacking. Sometimes they collide and get damaged. Therefore, the stacks must be installed with a certain distance or more so as not to collide with each other, and there is a problem that the device cannot be made compact.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to enable stable support while compacting the device even when the stack is divided into a plurality of parts so as to be advantageously mounted on a moving body. It is to provide a fuel cell.

[0006]

Means for Solving the Problems The present invention for achieving the above object provides a fuel cell constructed by sandwiching both ends of a stack in which single cells are stacked in multiple stages between an upper end plate and a lower end plate. The stack is divided into a plurality of pieces and arranged in parallel, and the upper end plates or the lower end plates of the adjacent stacks are connected by a connecting means.

When the stack is divided into a plurality of pieces in this way,
Since the height per stack is lowered with respect to a desired generated voltage and the center of gravity is lowered, stable support can be achieved even when the stack is mounted on a moving body that generates vibration or swing. Further, the rigidity against bending load is improved, which is advantageous for maintaining the sealing property. In addition, when the upper end plates or the lower end plates of adjacent stacks are connected to each other by the connecting means, the head side or the lower side of both stacks are constrained to each other. This can be avoided and the device can be made more compact.

The present invention will be described below with reference to the embodiments shown in the drawings. In FIGS. 1 and 2, reference numerals 1 and 1 denote stacks provided separately in left and right parallel, and each stack 1 is configured by stacking a large number of unit cells 2 in multiple stages. The structure of the unit cell 2 is the same as a known one, and has a structure in which a matrix layer impregnated with an electrolytic solution is interposed between an anode plate and a cathode plate.

The two stacks 1, 1 are supported on the lower side by a common integrated lower end plate 3, and the upper end plates 4 and 4 are individually brought into contact with the upper side, and the lower end plate is further supported. 3 is a tightening bar 5 having an X shape in a plan view, and a tightening bar 6 having an X shape in a plan view is provided outside the upper end plate 4.
And the spring 8 are used to fasten and fix them by four bolts 7 that penetrate the four corners.

At the X-shaped intersection of the upper tightening bar 6, four spring bearings 6a are integrally formed so as to sandwich the intersection, and the upper end of the spring 8 is engaged with the spring bearing 6a. The lower end of the upper end plate 4 presses the upper surface near the center of the upper end plate 4. By pressing the vicinity of the central portion of the upper end plate 4 in this manner, it is possible to uniformly tighten the internal power generation portion. Further, in this tightening, since the tightening bar 6 and the spring 8 are provided so as to overlap each other in a side view as described above, the height of the entire stack can be set low while ensuring a sufficient spring length. it can.

Plate-shaped heaters 12 are inserted in each stack 1 at a plurality of unit cells 2 at both end faces and at an intermediate position with a space therebetween. By inserting the plate-shaped heater 12, the temperature rising rise time in the initial operation of the fuel cell is shortened. In addition, we are trying to stabilize the power generation performance for a long period of time. Further, the inner manifolds 13a, 13b; 14 are provided on the inner sides of the four sides around each stack 1.
a and 14b are provided so as to penetrate vertically. Of these, fuel gas (hydrogen, etc.) flows from the inner manifolds 13a to 13b to the inner manifold 14a.
14b to 14b, the air is distributed and supplied into each of the multi-stage single cells 2, and both gases react with each other in the matrix layer in each of the single cells 2 to generate water and electric energy.

The stack tightening bolt 7 is covered with a resin tube 15 having high chemical resistance such as polytetrafluoroethylene resin as shown in FIG. 4, and is electrically insulated from the unit cell 2. In addition, it is protected against corrosion by electrolytes such as phosphoric acid. Such a protective film may be resin-coated by immersing the bolt 7 in a resin liquid. The tightening bolt 7 also has a positioning function at the time of assembling the stack, and an assembling jig can be eliminated.

Pins 9 and bolts 10 are fixed to the upper end plates 4 and 4 which are independently abutted on the two stacks 1 and 1, respectively, at positions facing each other. The connecting rod 11 is engaged to connect both stacks. The connecting rod 11 restrains the two stacks 1 and 1 from each other so that the heads do not collide with each other due to vibration or the like.

FIG. 3 shows the details of the connection structure. At the connecting portion of the connecting rod 11 to the bolt 10, the vibration-proof rubber 1 in which collars 17 and 18 are integrally baked on the inner circumference and the outer circumference is provided.
6 is press-fitted and fixed to the bolt 10 via the anti-vibration rubber 16 so that the anti-vibration rubber 16 cannot be rotated or moved up and down beyond the allowable deformation range. On the other hand, at the connecting portion on the pin 9 side of the connecting rod 11, the pin 9
In contrast, it is slidably fitted in the axial direction (stack stacking direction). Therefore, although both stacks 1 and 1 are constrained in the horizontal direction, relative movement is allowed in the stacking direction of the stacks, and even if there is a difference in the amount of deformation due to thermal expansion between the stacks, this is absorbed. However, a seal failure due to an unbalanced load is prevented.

In the illustrated embodiment described above, an example in which the upper end plates are connected to each other by the connecting rod has been described. However, contrary to this embodiment, the upper end plate side is common to all stacks. Alternatively, the lower end plate side may be independently separated for each stack, and the lower end plates may be connected to each other. In the fuel cell described above, stack 1 is not stacked as a single body to obtain a desired power generation voltage, but is separated into two stacks. Therefore, the height per stack is halved compared to the case where a single stack is stacked. Can be lowered. Therefore, the center of gravity can be lowered as a whole, and stable support can be achieved even when the center of gravity is mounted on a moving body such as a vehicle that vibrates or swings. In addition, since the stack per unit is low, the rigidity against bending load becomes large, and the unbalanced load due to bending does not act on the boundary surface between unit cells,
Prevents deterioration of sealing performance. The separation arrangement of such stacks is not limited to two as illustrated in this embodiment, and may be separated into three or more if necessary.

[0016]

As described above, in the fuel cell of the present invention, the stack is divided into a plurality of stacks so that the center of gravity of the fuel cell is lowered as a whole, and the fuel cell is stably supported even when mounted on a moving body where vibration or rocking occurs. be able to. Also, since the height of each stack becomes low, the rigidity against bending becomes high, and the unbalanced load due to bending deformation does not act on the boundary surface between single cells,
Prevents deterioration of sealing performance. In addition, since the upper end plates or the lower end plates of the adjacent stacks are connected to each other by the connecting means, it is possible to prevent the stacks from colliding even if the head side or the lower side of both stacks are narrowed. The device can be made more compact.

[Brief description of drawings]

FIG. 1 is a front view of a fuel cell according to an embodiment of the present invention.

FIG. 2 is a plan view of the fuel cell.

FIG. 3 is an enlarged front view showing a connecting portion between upper end plates of the fuel cell.

FIG. 4 is an enlarged cross-sectional view of the vicinity of a tightening bolt of the fuel cell.

[Explanation of symbols]

1 Stack 2 Single cell 3
Lower end plate 4 Upper end plate 9 Pin 10
Bolt 11 Connection rod (connection means)

Claims (1)

[Claims] 1. In a fuel cell constructed so that both ends of a stack in which unit cells are stacked in multiple stages are sandwiched between an upper end plate and a lower end plate, the stack is divided into a plurality of stacks and arranged side by side. A fuel cell in which upper end plates or lower end plates of stacks adjacent to each other are connected by a connecting means.