JPH0347251Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a fuel cell, and particularly to a tightening structure for a cell stack thereof.

[Conventional technology]

FIG. 3 shows the tightening structure of a conventional fuel cell, particularly its cell stack. The unit cell 1 is composed of a fuel electrode 2, a matrix 3 holding an electrolyte, an air electrode 4, and a separate plate 5, and a fuel cell stack 6 is constructed by stacking a large number of the unit cells 1. At both ends of the fuel cell stack 6, current collecting plates 7 for extracting electric power to the outside are provided, and clamping plates 9 are provided above and below with an insulating plate 8 in between. The fuel cell stack 6 is tightened in the stacking direction by tightening a disc spring 10 provided on the upper part of a tightening plate 9 with a tightening rod 11 and a nut 12.

[The problem that the idea aims to solve]

In the fuel cell described above, it is important to maintain the tightening load applied to the fuel cell stack 6 at an appropriate value in order to fully demonstrate the performance of the cell. However, because the carbon that makes up the fuel cell stack and the carbon steel that is the material for the tightening rods have different coefficients of thermal expansion, temperature changes that occur during battery operation cause a difference in the amount of elongation in the stacking direction, resulting in an increase in the tightening load. decreases. For this reason, in the past, the reduction in tightening load was prevented by making the stroke of the disc spring 5 to 10 times the difference in the amount of extension, but in order to lengthen the stroke of the disc spring, it was necessary to use a large number of disc springs. It was hot.

Therefore, with the conventional apparatus, there were problems such as the height of the cell stack becoming high, the cell stack not being able to fit within a predetermined limited space, or the pressure vessel housing the cell stack becoming large. This invention was devised in view of the above-mentioned problems, and aims to provide a compact fuel cell that can obtain an appropriate tightening pressure.

[Means to solve the problem]

In order to solve this problem, in the present invention, a plurality of unit batteries are stacked to form a cell stack, and clamping plates provided at both ends of the cell stack are used to secure the cell stack to a predetermined surface via clamping rods and disc springs. In a fuel cell in which the cell stack is tightened by pressure, the tightening rod penetrating portion of the tightening plate has an open portion at one end;
A disc spring storage case having a bottomed portion at the other end and having a length dimension larger than the thickness dimension of the tightening plate is provided, and the tightening rod, the disc spring, and the disc spring storage case are each substantially concentrically arranged. and the bottomed side of the disc spring storage case is arranged on the cell stack side of the tightening plate.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 and 2. In FIG. 1, the same members as in FIG. 3 are given the same reference numerals, and explanations thereof will be omitted. Also, the second
In the figure, the same members as in FIG. 1 are given the same reference numerals.

The embodiment shown in FIG. 1 is different from the conventional structure shown in FIG. The point is that the disc spring storage case 13 is provided which is larger than the thickness of the plate. The tightening rod 11, the disc spring 10, and the disc spring storage case 13 are each arranged substantially concentrically, and the bottomed side of the disc spring storage case 13 is located on the cell stack 6 side of the clamping plate 9, The disc spring storage case 13 has a fixing screw 14
It is fixed to the tightening plate 9 by.

FIG. 2 shows an embodiment in which the length L1 of the disc spring storage case 13 in FIG. 1 is lengthened as shown in L2 according to the number of disc springs. Even if a larger number of fuel cells is required, this can be done without changing the overall height of the fuel cell.

[Effect of idea]

As described above, according to this invention, a disc spring storage case is provided, which has an open end at one end and a bottomed part at the other end, and whose length is larger than the thickness of the tightening plate. Since the disc spring storage cases are arranged substantially concentrically, and the bottomed side of the disc spring storage case is arranged on the cell stack side of the tightening plate, when a large number of disc springs are used. However, the height of the fuel cell can be made smaller than before. Furthermore, since the disc spring storage case has a removable structure, it is possible to deal with the number of disc springs required by simply replacing the disc spring storage case.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the main part of a fuel cell showing an embodiment of the present invention, Fig. 2 is an explanatory diagram when the length dimension of the disc spring storage case in Fig. 1 is changed, and Fig. 3 is a conventional one. FIG. 2 is a side view illustrating the structure of a fuel cell. In the figure, 9: tightening plate, 10: disc spring, 1
1: Tightening rod, 13: Disc spring storage case.

Claims (1)

[Scope of utility model registration request] In a fuel cell in which a cell stack is constructed by stacking a plurality of unit cells, and the cell stack is tightened with a predetermined surface pressure via a tightening rod and a disc spring using tightening plates provided at both ends of the cell stack, the tightening plate A disc spring storage case having an open part at one end and a bottomed part at the other end and having a length larger than the thickness of the clamping plate is provided in the tightening rod penetrating part, and the disc spring storage case and a disc spring storage case are arranged substantially concentrically, and the bottomed side of the disc spring storage case is arranged on the cell stack side of the tightening plate.