JPH07259812A - Tightening device - Google Patents

Abstract

PURPOSE:To provide a tightening utensil which is lightweight and can tighten a work evenly. CONSTITUTION:On one end surface side of each boxlike fluid container 11 in whose inside a liquid is filled and which consists of a high molecule material, plural projection portions 12 that are of spherical surfaces and can be deformed are formed at predetermined positions so that the insides of the projection portions 12 and the inside of each fluid container 11 may be connected to each other, and each fluid container 11 is each provided on both layer accumulation direction end sides of a stack so that the projection portions 12 may butt against the stack, and end plates 13 are respectively provided so as to pinch the stack and the fluid containers 11, and tightening bolts 14 and tightening nuts 15 are provided at the four corners of the end plates 13 so that the confronting end plates 13 may be connected to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for tightening a work such as a stack such as a fuel cell stack.

[0002]

2. Description of the Related Art In order to obtain a predetermined electric power, a fuel cell is usually a device in which a plurality of unit cells are stacked in series (hereinafter referred to as a stack).

A schematic structure of such a fuel cell is shown in FIG. As shown in FIG. 6, the electrolyte 6a is applied to the electrode 6 in the thickness direction.
The cell 6 is sandwiched by b, the cell 6 is sandwiched in the thickness direction by the gas partition plate 7, and further sandwiched by the cooling plate 8 to construct the unit cell 10. A plurality of the unit cells 10 are stacked in the thickness direction (however, only one layer is shown in FIG. 6) to form a stack, and the stack is sandwiched by the end plates 3 and the four opposite corners of the end plates 3 are tightened. The bolts 4 and the tightening nuts 5 are tightened respectively.

[0004]

In the fuel cell as described above, since the four corners of the flat end plate 3 are tightened with the tightening bolts 4, the end plate 3 is easily bent. When the end plate 3 is bent, the stack tightening pressure becomes uneven, and the reaction gas and cooling water leak from the stack. Therefore, the rigidity of the end plate 3 is increased to prevent the end plate 3 from bending. However, since the end plate 3 is thick, the weight of the end plate 3 is heavy, and the end plate 3 is not easily transported or transported. It takes a lot of time to install it.

[0005]

In order to solve the above-mentioned problems, the present invention provides a fluid container in which a work is sandwiched and tightened and a fluid is filled therein, and the fluid container is provided so as to abut against the work. Moreover, the tightening device is configured by including the projecting portion that can be changed.

Here, the protrusion may be made of a deformable polymer material formed in a spherical shape.

Further, the projection may be made of a polymer material formed in a bellows shape so as to expand and contract.

The projection may be a rod slidably provided on the fluid container so as to expand and contract.

[0009]

In the tightening device having the above-described structure, when the work is sandwiched by the fluid container and tightened, the tightening pressure is transmitted to the projection through the liquid, and the projection tightens the work. At this time, when the fluid container bends due to the reaction from the work due to tightening, the protrusion changes according to the deflection of the fluid container, and the liquid in the fluid container presses the protrusion evenly as the protrusion moves. Since it is pushed back with, the work is always tightened evenly by the protrusion.

If the protrusion is made of a deformable polymer material formed in a spherical shape, the protrusion is deformed in accordance with the deflection of the fluid container, and the liquid is uniform as the protrusion deforms. Since it is pushed back with sufficient pressure, the work piece is always tightened evenly due to the protrusion.

If the protrusion is made of a polymer material formed in a bellows shape so as to expand and contract, the protrusion expands and contracts in accordance with the deflection of the fluid container, and the liquid projects as the protrusion expands and contracts. Since the part is pushed back with uniform pressure, the work piece is always tightened evenly by the protrusion.

Further, if the rod is slidably provided in the fluid container so that the projection portion expands and contracts, the rod expands and contracts in accordance with the deflection of the fluid container, and the projection portion expands as the liquid expands and contracts. Since it is pushed back with uniform pressure, the work is always tightened evenly by the rod.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the fastening device according to the present invention will be described with reference to FIGS. 1 to 3 when applied to a fuel cell stack which is an example of a work. 1 is a schematic configuration diagram thereof, FIG. 2 is a partially cutaway view of a main part thereof, and FIG. 3 is an operation diagram thereof.

As shown in FIG. 1, electrodes 6b are provided on both ends of the electrolyte 6a in the thickness direction, and the electrolyte 6a and the electrodes 6b constitute a cell 6. Gas partition plates 7 are provided at both ends of the cell 6 in the thickness direction. Cooling plates 8 are provided outside the gas partition plates 7, and the cells 6, the gas partition plates 7, and the cooling plates 8 constitute a single battery 10. A plurality of the unit cells 10 are stacked in the thickness direction (however, only one layer is shown in FIG. 1) to form a stack.

Box-shaped fluid containers 11 made of a polymeric material such as resin or rubber filled with a liquid such as oil or water are provided at both ends of the stack in the stacking direction. As shown in FIGS. 1 and 2, a plurality of spherical protrusions 12 are formed at predetermined positions on one end surface side of the fluid container 11, that is, on the stack side. The protrusions 12 are formed by molding. It is formed integrally with the fluid container 11. As shown in FIG. 2, the insides of the protrusions 12 communicate with the inside of the fluid container 11, respectively. These protrusions 12 can be deformed by pressing force. Fluid container 1
On the other end surface side of 1 is provided an injection port 11a communicating with the inside of the fluid container 11 so that the liquid can be injected into the inside of the fluid container 11. The inlet 11a is fitted with a sealing plug 11b that prevents the liquid inside from flowing out.

As shown in FIG. 1, end plates 13 are provided outside the fluid container 11 in the stacking direction. Tightening bolts 14 pass through the four corners of the end plates 13 so as to connect the end plates 13 facing each other.
The end plates 13 facing each other are provided on the tip side of the tightening bolts 14.
A tightening nut 15 is sandwiched between the tightening bolt 14 and the head 14a of the tightening bolt 14.

A case where the fuel cell stack is fastened with such a fastening tool will be described below. Turn the tightening nut 15 so that the tightening nut 15 and the head 14a of the tightening bolt 14
By shortening the distance between and, the facing distance of the end plate 13 is reduced, the facing distance of the fluid container 11 is reduced, and the protrusion 12 is pressed against the stack via the liquid in the fluid container 11 and the protrusion 12, Tighten.

When the tightening nut 15 is further rotated, as shown in FIG. 2, the end plate 13 and the fluid container 11 are bent due to the reaction from the stack accompanying the tightening. In response to this deflection, the protrusion 12 of the fluid container 11 is deformed,
The liquid in the fluid container 11 and the protrusions 12 pushes the protrusions 12 back with a uniform pressure as the protrusions 12 are deformed. That is, when the protrusion 12 near the tightening bolt 14 is compressed due to the bending, the liquid corresponding to the compression enters the protrusion 12 near the center of the stack. Therefore, the tightening pressures of the protrusions 12 on the stack are equal to each other, and the stack can be tightened with uniform tightening pressure.

Therefore, since it is not necessary for the end plate 13 and the like to have high rigidity, the overall weight of the fuel cell is lightened, and while facilitating transportation and installation, it is possible to prevent reaction gas and cooling water from leaking from the stack. There is no. Also, cell 6
The flatness is improved and the contact between adjacent cells 6 is improved, so that the current collecting effect is improved.

A case in which the second embodiment of the fastening device according to the present invention is applied to fastening a stack of a fuel cell which is an example of a work will be described with reference to FIG. Note that FIG.
FIG. 4 is a partially cutaway view of the main part. However, the same members as those in the above-described embodiment are designated by the same reference numerals as those in the above-described embodiment, and the description thereof will be omitted.

As shown in FIG. 4, a box-shaped fluid container 21 made of a polymer material such as resin or rubber, which is filled with a liquid such as oil or water, has a bellows-like protrusion on one end surface side thereof. A plurality of parts 22 are formed at predetermined positions, and the projections 22
Is integrally formed with the fluid container 21 by molding.
The insides of these protrusions 22 communicate with the inside of the fluid container 21, respectively. These protrusions 22 can be expanded and contracted by pressing force. 21a in FIG.
Is an inlet for injecting a liquid, and 21b is a sealing stopper.

When the fluid container 21 having such a protrusion 22 is used in the same manner as in the above-described embodiment, the protrusion 22 is formed.
In the same manner as in the above-mentioned embodiment, the stack is tightened with a uniform tightening pressure. Therefore, also in this embodiment, it is possible to obtain the same effect as that of the above-mentioned embodiment.

A case where the third embodiment of the fastening device according to the present invention is applied to fastening a stack of a fuel cell, which is an example of a work, will be described with reference to FIG. Note that FIG.
FIG. 4 is a partially cutaway view of the main part. However, the same members as those in the above-described embodiment are designated by the same reference numerals as those in the above-described embodiment, and the description thereof will be omitted.

As shown in FIG. 5, one end face side of a box-shaped fluid container 31 made of a metal material such as a steel plate or a stainless steel plate, which is filled with a liquid such as oil or water, has a cylindrical holding shape. A plurality of parts 31c are provided at predetermined positions so that the insides of the holding parts 31c communicate with the inside of the fluid container 31, respectively. Cylindrical rods 32 made of the metal material as described above are fitted into these holding portions 31c via seals 31d such as O-rings, and these rods 32 expand and contract with respect to the holding portions 31c. Each is slidable. Flange portions 32a are provided on both ends of these rods 32,
The rod 32 does not come off from the holding portion 31c. Hollow portions 32b communicating with the inside of the fluid container 31 are formed inside the rods 32, respectively, so that liquid can freely flow in and out. Incidentally, 31a in FIG.
Is an inlet for injecting a liquid, and 31b is a sealing stopper.

Fluid container 3 provided with such a rod 32
1 is used in the same manner as in the embodiment described above, the rod 32 is
Similar to the protrusions 12 and 22 of the above-described embodiment, the stack is tightened with a uniform tightening pressure. Therefore, also in this embodiment, it is possible to obtain the same effect as that of the above-mentioned embodiment.

In the above-described embodiments, the fluid containers 11, 21, 31 are filled with the liquid, but a gas such as air or nitrogen can be used without any particular problem. In the above-described embodiment, the end plates 13 are used to form the fluid containers 11, 21,
31 was pressed against the stack and tightened the stack,
A flange portion may be provided on the fluid container to replace the end plate.
Although the stack of the fuel cell is tightened in the above-described embodiment, the present invention is not limited to this, and any work that requires uniform pressure tightening may be used in the same manner as in the above-described embodiment.

[0027]

As described above, in the tightening device according to the present invention, even if the fluid container bends due to the reaction from the work due to the tightening, the protrusion changes depending on the deflection of the fluid container, and Since the liquid pushes back the protrusion with uniform pressure as the protrusion expands and contracts, the work is always clamped evenly by the protrusion. Therefore, for example, if it is used for tightening a stack of a fuel cell, it is not necessary to use an end plate having high rigidity, the overall weight of the fuel cell can be reduced, and transportation and installation can be facilitated, It does not leak reaction gas or cooling water. Further, the flatness of the cells is improved and the contact between adjacent cells is improved, so that the current collecting effect is improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram when a first embodiment of a fastening device according to the present invention is applied to a stack of a fuel cell which is an example of a work.

FIG. 2 is a partially cutaway view of its main part.

FIG. 3 is an operation diagram thereof.

FIG. 4 is a partial cutaway view of the essential parts of a second embodiment of the fastening device according to the present invention.

FIG. 5 is a partial cutaway view of the main parts of the third embodiment of the fastening device according to the present invention.

FIG. 6 is a schematic configuration diagram of a conventional fastening device for a fuel cell stack.

[Explanation of symbols]

 11 Fluid Container 12 Projection 13 End Plate 14 Tightening Bolt 15 Tightening Nut 21 Fluid Container 22 Projection 31 Fluid Container 32 Rod

Claims (4)

[Claims] 1. A tightening device, comprising: a fluid container in which a work is sandwiched and tightened and a fluid is filled therein; and a variable protrusion provided on the fluid container so as to abut against the work. Attached equipment. 2. The tightening device according to claim 1, wherein the protrusion is made of a deformable polymer material formed in a spherical shape. 3. The projecting portion is made of a polymer material formed in a bellows shape so as to expand and contract.
The tightening device described in. 4. The tightening device according to claim 1, wherein the protrusion is a rod slidably provided on the fluid container so as to expand and contract.