JP2001256991A - Cell voltage detecting terminal for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cell voltage detecting terminal of a simple structure capable of manufacturing good connecting conditions. SOLUTION: The terminal installation hole 15 in the separator 14 is provided with a recess 16 protruding inside the wall. As a result, this forms a confined part 18 narrower than the hole inlet. The cell voltage detecting terminal 21 to be inserted into the terminal installation hole 15 is provided with a return portion 24 which is able to pass the confined part 18 by means of its deformation elasticity. The return portion 24, after passing the confined part 18, recovers its original shape and engages with the recess 16 to be held in position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal used for detecting a voltage of each cell constituting a fuel cell, and a terminal mounting portion on a cell side to which the terminal is mounted.

[0002]

2. Description of the Related Art For example, there is known a fuel cell comprising a plurality of fuel cells each having an anode electrode and a cathode electrode opposed to each other with a fixed polymer electrolyte membrane interposed therebetween and sandwiched by a separator. ing. In a fuel cell, the fuel gas supplied to the anode electrode is ionized on the catalyst electrode, and moves to the cathode electrode via a moderately humidified electrolyte membrane. The electrons generated during that time are taken out to an external circuit and used as DC electric energy. To keep extracting such electric energy,
Each cell must be functioning well. In order to know whether or not each cell is in a normal state during the operation of the fuel cell, it is sufficient to measure the cell voltage. Conventionally, as a cell voltage detection terminal device, a plug-in type as shown in FIGS. Devices using terminals are known. This voltage detection terminal device,
A circuit board 3 for measuring cell voltage provided near the cells 2 constituting the fuel cell stack 1, a cell voltage detection terminal 4 fixed to the circuit board 3, and a terminal mounting hole 5 formed in the cell 2 It is comprised including.

In this voltage detecting terminal device, an inner wall of a terminal mounting hole 5 provided in the cell 2 and a cell voltage detecting terminal 4 inserted therein come into contact with each other, and the cell voltage is reduced.
, The cell voltage is measured from the potential difference between adjacent cells 2 in the circuit board 3 and transmitted to a fuel cell control device (not shown). Therefore, the abnormality of the cell 2 is detected as a decrease in the cell voltage.

[0004]

However, the above configuration has the following problems. (1) Since the cell voltage detection terminal 4 is simply inserted into the terminal mounting hole 5, wear between the cell 2 and the cell voltage detection terminal 4 due to expansion and contraction of the fuel cell stack 1 generated during operation of the fuel cell, A dimensional error may cause a contact failure, or the cell voltage detection terminal 4 may fall out of the terminal mounting hole 5 due to vibration or the like, and the cell voltage may not be detected during fuel cell operation.

[0005] (2) In the technical field of fuel cells, it is desired to reduce the size and thickness of a single cell from the viewpoint of miniaturization of equipment space. It has been formed as thin as possible. In order to provide the terminal mounting holes 5 in such a thin separator, high processing accuracy is required. Further, cell 2
In order to prevent a contact failure between the cell voltage detection terminal 4 and the cell voltage detection terminal 4, the gap between the cell voltage detection terminal 4 and the terminal mounting hole 5 needs to be set to about 0.2 mm or less. (3) When the cell voltage detection terminals 4 are inserted into the terminal mounting holes 5, since the thickness of each cell 2 is small and there are few gaps, it becomes difficult to insert the cell voltage detection terminals 4 and the work is troublesome. (4) The circuit board 3 must be mounted in consideration of the change so that the cell voltage detection terminal 4 can cope with the expansion and contraction of the fuel cell stack 1 generated during the operation of the fuel cell.

Japanese Patent Application Laid-Open Nos. 9-283166 and 11-339828 also disclose the same kind of technology. However, in the former method of mounting a voltage measurement output terminal of a fuel cell, the elastic force is not sufficient. Since only the tip of the banana clip is pressed against the inner circumference of the hole, it may easily come off due to external force.In the latter case of a fuel cell stack with a cell voltage measurement terminal, a projecting voltage is applied to the outer circumference of the separator. Since the measurement terminal is provided, there is a possibility that connection failure or breakage may occur due to easy contact or the like during handling.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and it is an object of the present invention to maintain a good connection state of a terminal with a simple structure and to effectively remove a terminal easily. And to improve the workability of attaching and detaching the terminals.

[0008]

In order to solve the above problems, the present invention employs the following constitution. The invention according to claim 1 provides a recess (terminal mounting hole 15) formed in a separator (14) of a fuel cell (fuel cell stack 11), and a terminal inserted into the recess to detect a voltage from the separator. A cell voltage detection terminal device for a fuel cell, comprising a cell voltage detection terminal 21) and a jaw (a protrusion 16) protruding from an inlet (terminal insertion port 17) and an inner wall of the recess. ), The terminal includes a barb portion (24) which can be moved over the jaw by elastic deformation, and the terminal is elastically restored after the barb portion has passed over the jaw. It is characterized in that it is retained in the recess.

According to this configuration, the terminal can be easily and reliably connected to the separator by utilizing the spring action of the barb portion, and a good connection can be maintained with a simple structure. . Further, when the barbs are elastically restored, the barbs and the jaws are engaged with each other, so that the terminal once connected to the separator does not easily come off.

According to a second aspect of the present invention, in the cell voltage detecting terminal device for a fuel cell according to the first aspect, the terminal is a circuit board (23) for measuring a detected voltage from the separator.
And a flexible portion (bent portion 26, bent portion 55, coil-shaped flexible portion 56) between the separator and the circuit board that allows relative displacement between the separator and the circuit board.

[0011] In this configuration, the flexure of the flexible portion appropriately absorbs the positional deviation generated when the cells are stacked or the like, so that the circuit board can be easily assembled to the fuel cell stack. In addition, when such a relative displacement absorbing action is exhibited, it is not necessary to consider a change in cell position that occurs during the operation of the fuel cell, and it is possible to maintain a good connection state.

According to a third aspect of the present invention, in the cell voltage detecting terminal device for a fuel cell according to the first or second aspect, the terminal is inserted from the inlet to the outside of the separator while being inserted into the recess. And a surplus portion (25) extending from the barb portion so as to protrude therefrom.

In this configuration, the engagement of the barb with the jaw can be easily released by operating the extra length, so that the terminal can be easily and easily removed. .

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a main part of a fuel cell cell voltage detecting terminal device according to the present embodiment, and FIG. 2 is a sectional view of the device.

In FIG. 1, reference numeral 11 denotes a polymer electrolyte fuel cell stack. The fuel cell stack 11 is formed by stacking a number of cells 12. Each cell 12
Is a membrane / electrode assembly (hereinafter abbreviated as “MEA”) 13 in which a fuel electrode and an air electrode are respectively joined to both surfaces of a solid polymer membrane, and a separator 14 that sandwiches the MEA 13 from both sides. It is configured with.

The separator 14 is made of a dense carbon plate or metal plate that does not allow gas to permeate, and has a groove-shaped gas flow path (one side) that faces the MEA 13 when a cell is formed. (Not shown) is formed.
Hydrogen is supplied to the gas flow path of the separator 14 in contact with the fuel electrode, and hydrogen is supplied to the separator 14 in contact with the air electrode.
By supplying air to the gas flow path, power is generated between these electrodes based on an electrochemical reaction.

One separator 14 constituting the cell 12
The other side surface, that is, the side surface 14A which faces the separator 14 of another cell 12 which is adjacent when the fuel cell stack is formed, has a terminal mounting hole in which a terminal insertion port 17 which is an inlet portion is opened on the upper surface 14B. (Recess) 15 is formed. As shown in FIG. 2, the terminal mounting hole 15 has a substantially wedge-like vertical cross section, and is formed by a convex portion (jaw) 16 protrudingly formed on the inner wall of the terminal insertion port 17 side.
The configuration is provided with a narrow portion 18 having a smaller cross section than that of FIG.

Reference numeral 21 denotes a cell voltage detection terminal (terminal) made of a conductive wire such as copper or stainless steel. The cell voltage detection terminal 21 has a hairpin-type insertion portion 22 formed on the tip end side so as to be engaged with (engaged with) the inner wall of the terminal mounting hole 15. It is fixed to a circuit board 23 for measurement.

The insertion portion 22 has a barbed portion 24 which can be elastically oscillated from the folded portion 23 as a starting point, and extends from the barbed portion 24, and the insertion portion 22 is inserted into the terminal insertion hole 15. And an extra length portion 25 protruding from the terminal insertion opening 17 to the outside of the separator 14. Also, cell voltage detection terminal 2
A bent portion (flexible portion) 26 for absorbing a relative displacement between the cell 12 and the circuit board 23 is provided in the vicinity of the middle of 1.

When connecting the cell voltage detection terminal 21 to the cell 12 (separator 14), the insertion part 22 is positioned above the terminal insertion hole 15 and the insertion part 22 is pushed from above.
Then, the wedge-shaped insertion portion 2 corresponding to the terminal insertion hole 15 is formed.
2 is inserted while being elastically deformed. When the insertion portion 22 passes over the narrow portion 18, the barbed portion 24 is elastically deformed in the projecting direction of the convex portion 16 with the folded portion 23 as a starting point, so that before the elastic deformation, the insertion is wider than the narrow portion 18. Part 2
2 can also easily pass over the narrow portion 18.

When the insertion portion 22 is inserted to a predetermined position, the barb portion 24, which has been elastically deformed so as to pass through the narrow portion 18, moves in a direction opposite to the projection direction of the projection with the folded portion 23 as a starting point. The cell voltage detection terminal 21 is connected so as not to fall out of the cell 12 due to vibration or the like because the cell voltage detection terminal 21 is engaged with the projection 16 in the terminal insertion hole 15 by being restored by elasticity.

At this time, the cell voltage detecting terminal 21 always comes into contact with the cell 12 due to the resilient force generated when the barb portion 24 tries to return to the original shape, so that not only the retaining but also a good contact state is secured. Furthermore, during fuel cell operation,
Since the used length of the cell voltage detection terminal 21 can be changed by extending the bent portion 26 provided near the center of the cell voltage detection terminal 21, the relative displacement between the circuit board 23 and the cell 12 is reduced. Can be absorbed.

When simultaneously connecting a plurality of cell voltage detection terminals 21 to a plurality of cells 12, a circuit board 23 to which a plurality of cell voltage detection terminals 21 are fixed in advance is prepared. At this time, the interval between the cell voltage detection terminals 21 is set to the interval since the interval between the cells 12 when the fuel cell stack 11 is not pressurized or the like is known in advance from a design value or the like.

Then, the circuit board 23 is lightly inserted into the terminal insertion hole 15 at a predetermined position in the horizontal direction with respect to the fuel cell stack 11 and the insertion portion 22 of the cell voltage detection terminal 21 in the vertical direction. Is provisionally positioned so that Then, the connection jig 31 is pressed from above between the bent portion 26 and the insertion portion 22 so that the insertion portion 22 is inserted deeply into the terminal insertion hole 15.

When the connection jig 31 moves a predetermined distance, it is determined that the cell voltage detection terminal 21 is connected to the cell 12, and the connection jig 31 is separated from the cell voltage detection terminal 21. This completes the connection work. In the connection jig 31,
A groove for terminal guide may be provided at an equal interval to an interval between the cell voltage detection terminals 21 fixed to the circuit board 23,
In such a case, each cell voltage detection terminal 21 can be connected to the cell 12 while maintaining the cell voltage detection terminal 21 at a fixed interval, so that workability can be improved.

As a method of confirming the temporary insertion state of the cell voltage detection terminal 21, there is also a method of confirming the position of the insertion portion 22. When the circuit board 23 is provisionally positioned, when the insertion portion 22 of the cell voltage detection terminal 21 is normally temporarily inserted into the terminal insertion hole 15, the circuit board 23 is closer to the circuit board 23 than when it is not temporarily inserted. Since the insertion portion 22 is located, the temporary insertion state of the cell voltage detection terminal 21 can be determined by detecting the position.

After that, the insertion portion 22 is connected to the terminal mounting hole 1.
Similarly, when the plug is pushed into the plug 5, the plug 22 is located closer to the circuit board 23 than when the plug is not completely inserted. The insertion state of the detection terminal 21 can be determined.

The circuit board 23 is moved in the same direction as the cell voltage detection terminals 21 in accordance with the attachment of the cell voltage detection terminals 21 and fixed to the fuel cell stack 11. When the cell voltage detection terminal 21 is detached from the cell 12, the circuit board 23 is pressed by using the detachment jig 32 while pushing the extra length 25 protruding from the terminal insertion port 17 to the outside of the separator 14 in the projection direction. By separating the cell voltage detection terminal 21 from the fuel cell stack 11,
Disconnect from

That is, the extra length portion 25 is
Is pressed, the barbed portion 24 is elastically deformed in a direction away from the convex portion 16 with the folded portion 23 as a starting point, and the convex portion 16 is deformed.
Is released, so that the insertion portion 22 can be pulled out of the narrow portion 18. Therefore, the circuit board 2
3 is lifted, the insertion portion 22 easily comes out of the terminal insertion hole 15.

By using the above method, a plurality of cell voltage detection terminals 21 can be simultaneously and easily attached and detached, and automation can be facilitated. Further, according to the cell voltage detection terminal device for a fuel cell according to the present embodiment, the cell voltage detection terminal 21 is easily and reliably connected to the cell by utilizing the spring action of the insertion portion 22 provided in the cell voltage detection terminal 21. In addition to being able to be connected, poor contact can be effectively prevented by the elasticity of the insertion portion 22.

Further, the relative displacement generated between the circuit board 23 and the cell 12 can be absorbed by the bent portion 26 provided in the middle of the cell voltage detecting terminal 21. It is not necessary to consider the change in position, and the circuit board 23 can be easily assembled to the fuel cell stack 11. Further, by engaging the barbs 24 of the cell voltage detection terminals 21 with the projections 16 of the terminal insertion holes 15, the once connected cell voltage detection terminals 21 do not easily come off unless a disconnection operation is performed. .

Next, with reference to FIGS. 2 and 3, an example of a configuration example and an operation example of the automatic system for attaching and detaching the cell voltage detection terminal 21 will be described. This system automates the positioning process of the fuel cell stack 11 and the circuit board 23 and the attaching / detaching process of the cell voltage detecting terminal 21. In addition to the connecting jig 31 and the removing jig 32, the control unit 4
1, a driving unit 42 for driving the connection jig 31 and the like, for example, a position detecting unit 43 having an optical sensor, and the fuel cell stack 1
1 is provided with a pedestal 44 on which is mounted.

Hereinafter, an operation example of the present system will be described. To connect the cell voltage detection terminal 21 to the cell 12,
First, the pedestal 44 is driven via the drive unit 42 by a control signal from the control unit 41 to position the fuel cell stack 11. This positioning is performed based on an output signal from the position detection unit 43 to the control unit 41.

Similarly, the circuit board 23 is positioned with respect to the fuel cell stack 11. The positional relationship between the circuit board 23 and the fuel cell stack 11 is as described above. Next, the connection jig 31 is driven downward by the control signal from the control section 41 via the drive section 42, and the insertion section 22 of the cell voltage detection terminal 21 is completely inserted into the terminal mounting hole 15 of the cell 12.

Conversely, in order to remove the cell voltage detection terminal 21 from the cell 12, first, the removal jig 32 is driven by a control signal from the control unit 41 via the drive unit 42, and the cell voltage detection is performed by the removal jig 32. The extra length 25 of the terminal 21 is pushed along the direction in which the projection 16 projects. Then
The barb portion 24 is separated from the convex portion 16 and the insertion portion 22 of the cell voltage detection terminal 21 exceeds the narrow portion 18 so that the terminal insertion hole 1 is formed.
5, the circuit board 23 is driven upward by the control signal from the control unit 41 via the drive unit 42, and the cell voltage detection terminal 21 is detached from the cell 12.

The present invention is not limited to the above embodiment, but includes the following embodiments. (1) The insertion part 22 of the cell voltage detection terminal 21 and the terminal mounting hole 15 of the separator 14 are replaced with the insertion part 51 and the terminal mounting hole 52 of the form shown in FIG. According to this configuration, the engagement between the convex portion 26 and the barb portion 24 is performed at two places, so that it is possible to more effectively prevent detachment and poor contact.

(2) The flexible portion provided in the middle of the cell voltage detection terminal 21 is replaced with the bent portion 26 shown in FIG. 2 and replaced with a bent portion 55 shown in FIG. 5 or a coiled flexible portion 56 shown in FIG. thing. In consideration of the fact that the space in the cell stacking direction is extremely small, it is preferable that the bent portions 26 and 55 be bent in the direction in which the cell 12 and the circuit board 23 are separated from each other (the vertical direction in FIG. 2). . (3) The narrow portion 18 is a portion having the smallest cross section in the internal space of the terminal mounting hole 15. For example, as shown in FIG. 7, a narrow portion 18 may be provided in the terminal insertion port (entrance) 17. Even with this configuration, the insertion portion 22 can be reliably attached to and detached from the terminal mounting hole 15 by the same operation as described above, and the workability can be improved.

[0038]

As is apparent from the above description, according to the present invention, the following effects can be obtained. (1) According to the first aspect of the present invention, the cell voltage detection terminal can be easily and reliably connected to the separator by using the spring action of the barb portion, and a good connection state is maintained with a simple structure. can do. Further, when the barb portion elastically returns in the recess, the barb portion and the jaw are engaged with each other, so that the terminal once connected does not easily come off. Further, since the terminal connection is performed inside the separator, the terminal does not protrude from the separator surface, and is hardly damaged.

(2) According to the second aspect of the present invention, the flexible portion flexibly bends to absorb the positional deviation generated at the time of stacking the cells, so that the circuit board can be easily assembled to the fuel cell stack. And workability can be improved. In addition, when such a relative displacement absorbing action is exhibited, it is not necessary to consider a change in cell position that occurs during fuel cell operation, so that a good connection state can be maintained.

(3) According to the third aspect of the present invention, it is possible to easily release the engagement between the barb section and the jaw section by operating the extra length section. The operation can be performed easily and easily, and the workability can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a fuel cell cell voltage detection terminal device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of the fuel cell cell voltage detection terminal device.

FIG. 3 is a system configuration diagram showing one configuration example of a system for automatically attaching and detaching cell voltage detection terminals.

FIG. 4 is an enlarged sectional view of a main part showing another embodiment of a concave portion and a barbed portion according to the present invention.

FIG. 5 is a sectional view of a main part showing another embodiment of the flexible part according to the present invention.

FIG. 6 is a cross-sectional view of a main part showing still another embodiment of the flexible part according to the present invention.

FIG. 7 is a main part enlarged sectional view showing still another embodiment of the concave portion according to the present invention.

FIG. 8 is a perspective view showing a conventional example of a cell voltage detection terminal device for a fuel cell.

FIG. 9 is a sectional view of a main part of the fuel cell cell voltage detection terminal device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 fuel cell stack 12 cell 14 separator 15, 52 terminal mounting hole (recess) 16 projection (jaw) 17 terminal insertion port (entrance) 18 narrow part 21 cell voltage detection terminal (terminal) 23 circuit board 24 barring part 25 Extra length 55, 26 Bend (flexible) 56 Coiled flexible (flexible)

Claims (3)

[Claims] 1. A fuel cell cell voltage detection terminal device comprising: a recess formed in a separator of a fuel cell; and a terminal inserted into the recess for detecting a voltage from the separator. Comprises an inlet portion and a jaw projecting from an inner wall of the concave portion.The terminal includes a barb portion capable of exceeding the jaw portion by elastic deformation, and the barb portion is provided with the barb portion. A cell voltage detection terminal device for a fuel cell, wherein the cell voltage detection terminal device is prevented from falling into the concave portion by elastically restoring after passing over the jaw. 2. The device according to claim 1, wherein the terminal is connected to a circuit board for measuring a detection voltage from the separator, and further comprises a flexible portion between the separator and the circuit board for allowing relative displacement between the separator and the circuit board. The cell voltage detection terminal device for a fuel cell according to claim 1, wherein 3. The terminal according to claim 2, wherein the terminal has an extra length extending from the barb portion so as to protrude from the inlet to the outside of the separator when inserted into the recess. 3. The fuel cell voltage detection terminal device according to claim 1 or 2.