JPH0158835B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] Rectangular plate-shaped units constituting a cell stack are stacked between a pair of tightening members, and are spanned between the four corners of both said tightening members. The present invention relates to a method of stacking a fuel cell stack, in which the stack of units is fastened between both fastening members using a fastening rod.

[Prior art and its problems]

A cell stack of a fuel cell is a stack of rectangular plate-shaped units consisting of a unit cell and plates with grooves for holding the cell and supplying a reaction gas, and is installed at the four corners of a pair of clamping members. Although it is constructed by being tightened by a tightening rod, it is difficult to vertically stack a large number of rectangular plate-shaped units without tilting them or disrupting their arrangement due to stacking.
For this reason, as a conventional technique, a rectangular square bar is placed upright on the bottom plate, which is the tightening member of the cell stack, to form a stacking jig, and on the other hand, two opposing sides of a square plate-like unit are provided with notches into which the square bars can fit. A cell stack is stacked using a stacking jig as a guide. The prior art will be explained below based on the drawings. FIG. 1 is a front view showing the prior art, and FIG. 2 is a plan view thereof. In FIG. 1, reference numeral 1 indicates a lower end plate which is a bottom plate, and rectangular plate-shaped unit bodies 2 are stacked on this lower end plate 1 to form a cell stack. The cell stack consists of a stacking jig 3 consisting of a rectangular square bar standing upright on a lower end plate 1, and a U-shaped notch provided on two opposing sides of a square plate-shaped unit body 2 as shown in FIG. 2a, the unit bodies 2 are stacked and assembled, and after assembly is completed, the upper end plate (not shown) is placed on top of the cell stack, and the fasteners provided at the four corners of the upper and lower end plates (not shown) are placed on top of the cell stack. The cells are tightened with the attachment rods, and the stacking jig 3 is removed to form a cell stack.
Normally, the stacking jig 3 for stacking the unit bodies 2 needs to have rigidity so that the cell stacks are not tilted and stacked vertically without disturbing the arrangement due to stacking. Particularly in the case of large fuel cells, the area of the cell is large and the height of the cell stack is also large, so in the conventional stacking method, the stacking jig used must be large to ensure its rigidity. However, there are limitations on the size of the notch that can be made in the unit body 2, so it is not practical. Furthermore, the conventional technique has the disadvantage that it requires the effort of machining the notches 2a in the unit body 2.

[Purpose of the invention]

In view of the above-mentioned drawbacks, this invention uses a lamination jig that can easily obtain rigidity in a practical manner.
It is an object of the present invention to provide a fuel cell stack stacking method that allows square plate-shaped units to be stacked and tightened accurately.

[Key points of the invention]

When stacking rectangular plate-shaped units of fuel cells, in this invention, the clamping rods of the fuel cell stack, for example, three of the studs provided at the four corners of the upper and lower end plates, which are a pair of clamping members, are stacked. The cell stack's upper end plate is supported by a nut at the top of the stud. At this time, the interval between the lower end plate and the upper end plate is set higher than the height of the cell stack, and at a distance that allows insertion of the lamination jig.

Next, a stacking jig that serves as a guide is placed in contact with two intersecting sides of the rectangular plate-shaped unit, and is adjusted and attached to the stud so that the rectangular plate-shaped unit is installed at the required position on the lower end plate. In this state, the lamination jig has a structure in which the upper and lower end plates are connected with three studs, and the rigidity of the lamination jig can be ensured sufficiently, so the unit without notches can be pressed against the lamination jig. If you stack the units while doing so, the units will be stacked accurately. After stacking,
Insert the remaining studs and tighten them with the lamination jig attached to each tightening rod. After this, by removing the stacking jig, an accurately stacked fuel cell stack can be obtained.

[Embodiments of the invention]

Embodiments of the present invention will be described below based on the drawings. FIG. 3 shows the installation of the lamination jig according to the present invention,
FIG. 4 is a front view of an embodiment in which rectangular plate-shaped unit bodies are stacked, and FIG. 4 is a cross-sectional view taken along line XX. In the figures after FIG. 3, the same parts as in FIGS. 1 and 2 are given the same reference numerals. In Fig. 3, the studs 4a, 4b, and 4c have a rectangular cross section only for a length slightly shorter than the length of the attachment part of the lamination jig 3, and both ends are round rod-shaped and threaded at each tip. . The studs 4a, 4b, and 4c are inserted into the reamed holes of the lower end plate 1, erected vertically, and tightened with nuts, respectively. A lamination jig 3 is removably attached to the rectangular side of the stud with bolts 3a.

The tops of the studs 4a, 4b, 4c have a margin greater than the height of the cell stacks on which the upper end plate 5 is stacked, and are held by nuts at intervals that allow the stacking jig 3 to be attached and removed. Therefore, the lower end plate 1 and the upper end plate 5 have three studs 4.
A, 4b, and 4c are connected to each other to ensure sufficient rigidity, and since there are no remaining studs, the work of stacking the units becomes easy. As shown in FIG. 4, there is one lamination jig 3 on the stud 4a,
2 on the stud 4c and 1 on the stud 4c, so that the rectangle formed by the 4 guide surfaces 3b that guide the sides of the rectangular plate-shaped unit 2 of the laminating jig 3 forms the required position and shape. The lamination jig 3 is adjusted and attached with tightening bolts 3a. In this state, the rectangular plate-shaped unit bodies 2 are stacked while being pressed against the guide surface 3b of the stacking jig 3. With this method, the rectangular plate-shaped unit body 2 is attached to the required position of the lower end plate 1, and the lamination jig 3 is attached to a rigid structure, so that the unit body 2 does not tilt.
They are stacked vertically along the guide surface 3b of the stacking jig 3 without any disturbance in the arrangement due to stacking.

After the cell stack of the desired height is stacked,
Loosen the nut and remove the upper end plate 5.
Insert the fourth stud into the reamed hole 6 of the lower end plate 5 and stand it vertically, then fit the upper end plate 5 again and place it on the top surface of the cell stack. At this time, the laminating jig 3 is attached to two sides of the square of this stud, and the laminating jig 3 is attached to each of the vacant sides of the square of the studs 4a and 4c. Tighten while applying it to all sides of the cell stack. This method allows the cell stacks to be stacked vertically without tilting or disrupting the alignment due to stacking. Note that after the tightening is completed, all the tightening jigs 3 are removed. FIG. 5 is a front view showing the state after the cell stack has been stacked, and FIG. 6 is a cross-sectional view taken along the Y-Y line in FIG. are fastened between the lower end plate 1 and the upper end plate 5 by studs 4a, 4b, 4c, and 4d. Note that a spacing ring 7 is inserted between the upper end plate 5 and the threaded portion of the stud to enable tightening with a screw.

As shown in FIG. 7, the cross section of the stud, for example, the stud 4a, other than the two sides in contact with the guide surface 3a of the laminating jig 3, may not be straight, but may be circular, for example.

FIG. 8 shows a different embodiment of the present invention, in which the upper end plate 5 is supported on studs without using lower nuts. In Fig. 8, a reamed hole is provided in the round bar part of the stud inserted into the upper end plate 5 at the same position as the reamed hole in the lower end plate 1, and the stud connects the upper and lower end plates. Insert the U-shaped spacing piece 8 between the bottom of the plate 5 and the shoulder of the stud, and hold the spacing piece 8 on the round bar of the stud as shown in Figure 9, which shows the Z-Z cross section of Figure 8. In addition, this figure shows a structure in which the upper end plate 5 is supported by being tightened with nuts from its upper surface, and the stacking method of the fuel cell stack is the same as described above.

FIG. 10 shows a different embodiment of the present invention, in which only one of the four corners is provided with a notch into which the stud is inserted, instead of a hole into which the stud is inserted. In FIG. 10, the lower end plate 5
The three corners of the upper end plate 1 are provided with reamer holes 6 into which the round rod portion of the stud is inserted, and the remaining corner is provided with a U-shaped notch 6a at the same position as the reamer hole 6 and the lower and upper plates. and lower end plate 1 and upper end plate 5
are connected by three studs (not shown), and a U-shaped spacing piece 8 is interposed between the shoulder of the stud and the lower surface of the upper end plate 5 and tightened as shown in FIG. During assembly, rectangular plate-shaped units are stacked using a stacking jig 3 attached to the studs of this structure. After the stacking is completed, the fourth stud can be inserted from the side into the notches 6a of the upper and lower end plates without removing the upper end plate 5, and by removing the three U-shaped spacing pieces 8, the upper end can be inserted. The plate 5 abuts against the upper surface of the cell stack, and the four studs can tighten the cell stack.

〔Effect of the invention〕

This invention utilizes the rigidity of the structure composed of the upper end plate, lower end plate, and studs to create a stacking jig that serves as a guide when stacking the rectangular plate-shaped unit bodies of fuel cells.
By attaching the units to the studs of the constituent members, the rectangular plate-shaped units can be vertically stacked in a predetermined position on the lower end plate without tilting or disrupting the arrangement due to stacking, and can be easily tightened in this state. There is an effect that it can be done. Furthermore, since the guide surfaces of the lamination jig are in contact with the two intersecting sides of the rectangle, there is no need for the processing effort of providing guide notches on the side surfaces of the rectangular plate-shaped unit. Especially in large fuel cells, the unit area becomes large and the height of the cell stack also becomes large.
Although rigidity is required for the lamination jig, according to the present invention, unlike the prior art, the lamination jig does not become too large, and there is no need for corresponding notches in the unit body. This method is highly effective for cell stacks made of stacked rectangular plate-shaped units of large fuel cells.

[Brief explanation of drawings]

FIG. 1 is a front view showing a cell stacking method according to the prior art, FIG. 2 is a plan view thereof, FIG. 3 is a front view showing an embodiment of the present invention, and FIG. 4 is an X--
5 is a front view after stacking rectangular plate-shaped units according to the present invention, FIG. 6 is a Y-Y sectional view in FIG. 5, and FIG. 7 is a sectional view of a different embodiment of the stud. Figure 8 is a front view showing different embodiments of supporting the upper plate of the present invention, Figure 9 is an enlarged Z-Z cross-sectional view of the stud portion in Figure 8, and Figure 10 is an attachment of the stud in the present invention. FIG. 6 is a plan view showing different embodiments of an end plate provided with holes. DESCRIPTION OF SYMBOLS 1... Lower end plate, 2... Unit body, 3... Lamination jig, 4a, 4b, 4c, 4d... Stud, 5
...Top end plate.

Claims (1)

[Scope of Claims] 1. Rectangular plate-shaped units constituting a cell stack are stacked between a pair of tightening members, and the units are secured by tightening rods stretched between the four corners of both tightening members. A method for stacking a fuel cell stack in which a laminate of the following is clamped between both clamping members, the method comprising: passing at least three of the clamping rods between the clamping members;
The clamping rod and the clamping member are rigidly assembled with the interval between both clamping members set to be larger than the dimension after tightening, and a laminating jig is provided to guide the two intersecting sides of the unit body. It is characterized by being detachably attached to a tightening rod, and after stacking the units between both tightening members using the stacking jig as a guide, the stack of units is tightened between both tightening members by the tightening rod. A method for stacking fuel cell stacks. 2. A method for stacking fuel cell stacks according to claim 1, characterized in that the stacking jig is removed after the stack is tightened.