Cell voltage pickup having a grid geometry

Abstract

The invention relates to a fuel cell voltage pickup (100) for electrically contacting a contact device of a fuel cell stack (20) of the fuel cell having electrical contact sockets (21) arranged in one or more rows and / or columns, the contact device having a housing (15), the cell voltage pickup (100) having spring contact elements (11) at corresponding positions, the spring contact elements (11) being formed by wire loops and extending away from the cell voltage pickup (100) in the plug-in direction (S), the spring contact elements (11) forming needle-ear-shaped wire loops (12) which are resiliently compressed when the spring contact elements (11) are inserted into the contact sockets (21) such that two wire loop sections of the wire loop (12) of the spring contact elements (11) are pressed transversely to the plug-in direction (S) against the contact sockets (21) under a spring force, the contact sockets (21) being provided with latching means (23) that secure the wire loops (12) in the plugged-in state.

Description

[0001] Cell contact unit with locking geometry

[0002] Description:

[0003] The invention relates to a cell contact unit CVP, also called cell voltage pickup.

[0004] A cell voltage pickup (CVP) is a multi-channel potential pick-up for detecting cell voltages in battery or fuel cell stacks, as well as bipolar plates. Different design principles are used depending on the stack used.

[0005] Such a device is known from the prior art, for example, from JP 002002313398 A. This unit is used to measure cell voltage and is capable of simultaneously and easily measuring the voltages of all cells in a fuel cell stack. For this purpose, it comprises a plurality of voltage measurement probes and needle-like voltage measurement terminals with a tip protruding from the unit, as well as a spring mounted in the unit that preloads the needle-like voltage measurement terminals against the side surfaces of the separators of the fuel cell stack through an elastic force.

[0006] The disadvantages of this solution are the complex structure and the problem that, on the one hand, the contacts or the contact sockets can be damaged when plugged together and, on the other hand, a high plugging force is required, especially with a large number of fuel cell connections.

[0007] The invention is therefore based on the object of overcoming the aforementioned disadvantages and developing a solution for a fuel cell stack that allows for the safe, rapid, and reliable, and particularly automated, contact of a plurality of parallel bipolar plates in order to tap the cell voltage and then transmit it to measurement and evaluation electronics. Furthermore, it must be ensured that the corresponding contact enters the correct contact opening in the bipolar plate without damage, and that a good contact force is achieved there.

[0008] Furthermore, it is a goal to ensure reliable and safe contact that does not come loose accidentally, especially during operation.

[0009] This problem is solved by the combination of features according to patent claim 1.

[0010] A basic concept of the invention is that a specifically shaped, spring-loaded contact part, which has the shape of a "loop," deflects laterally when inserted into the corresponding contact pockets in the loop section. For this purpose, the width of the wire loop in the loop section is larger than the opening width on the side of the mating contact in order to achieve secure contact. The loop design enables deflection on both sides. Optionally, the wire loop can be additionally elastically deflected transversely to the insertion direction by a guide rod before reaching the end position. In this way, the connection can be established with a low but defined insertion force, and a high contact force can be generated when fully inserted.

[0011] Optionally, pre-centering can be achieved for better fixation via the housing, which provides a guide leg or guide ribs for this purpose.

[0012] According to the invention, a cell contacting unit is therefore provided, specifically for electrically contacting a contact device of a fuel cell stack, said contact device comprising a housing, with electrical contact sockets arranged in one or more rows and / or columns, wherein the cell contacting unit has spring contact elements at corresponding positions which extend away from the cell contacting unit in the plug-in direction (S), wherein the spring contact elements form a needle-eye-shaped wire loop at their plug-in end, which is spring-elastically compressed when the spring contact elements are plugged into the contact sockets, so that two wire loop sections of the wire loop of the spring contact elements are pressed against the contact sockets under spring force transversely to the plug-in direction (S), wherein the contact sockets have locking means (preferably integral) which fix the respective wire loops in the plugged-in state.

[0013] In an advantageous embodiment of the invention, it is provided that the contact sockets have a cavity corresponding to the shape of the wire loops or a correspondingly shaped receiving space, in which the respective wire loop, when plugged in, electrically contacts the contact socket partially or along the entire wire loop sections (but in principle forms a loop with a central opening).

[0014] It is further advantageous if, in the inserted state, a locking dome, locking lug, or projection (as a locking means) provided in the area of ​​the cavity protrudes at least partially or completely through the opening in the wire loop. In such an embodiment, the loop can wrap around the dome, thus engaging the dome in the loop opening in a secure manner.

[0015] Also advantageous is a design in which an inclined ramp is provided in the area of ​​the cavity, viewed in the insertion direction in front of the locking means, which serves as an inclined sliding bearing plane for guiding the wire loop when inserting it into the plug-in position.

[0016] In an advantageous embodiment of the invention, the cavity further comprises rounded side walls as a lateral counter-bearing for the resilient engagement of the wire loop sections. It is particularly advantageous if the cavity and / or the locking dome / locking lug are produced by deep drawing.

[0017] In a further advantageous embodiment of the invention, it is provided that the main component of the spring force, which presses the wire loop of the spring contact elements against a side wall of the contact sockets in the inserted state, acts transversely to the plugging direction.

[0018] It is further advantageous if the cell contacting unit is designed such that, when the spring contact elements of the cell contacting unit are plugged together with the contact sockets of the fuel cell stack, the wire loops of the spring contact elements are increasingly compressed during the plugging process due to the shape of the wire loop. This allows the plugging force to be controlled in a targeted manner along the plugging path. In a further advantageous embodiment of the invention, the wire loop is formed as a closed wire loop comprising at least two bent wire loop sections running alongside one another and a bent section formed at the end on the plugging side that connects these two wire loop sections.

[0019] Another advantage is a design in which the spring contact elements initially penetrate, at least with their front ends, into the contact openings of the contact sockets during mating, preferably approximately centrally, before the two wire loop sections encounter the wall sections of the contact sockets during further mating. Alternatively, an additional force component can be generated transversely to the mating direction by offsetting two parallel wire loops.

[0020] Also advantageous is a design in which the contact sockets have a contact cavity which, viewed in the plug-in direction, initially has an area with a smaller cross-section and then an area with a larger cross-section which clamps the wire loop when fully inserted.

[0021] Thus, it is also conceivable as a possible variant to form U-shaped contacts, each of which forms two essentially parallel (paired) spring contact elements, each of which spring contact elements is intended to be plugged into a corresponding socket on the contact device of the fuel cell stack.

[0022] As a further embodiment, the spring contact elements can have a locking geometry at or near their plug-in end, which engages with a counter-locking geometry formed in or on the contact sockets. This ensures secure holding of the contact arrangement. A further aspect of the present invention relates to such a contact arrangement consisting of a fuel cell stack with socket contacts and a cell contacting unit as described above, which is designed to be plugged together with the fuel cell stack in an electrically contacting manner.

[0023] A further aspect of the present invention relates to a fuel cell comprising a fuel cell stack with a plug-in device formed with socket contacts and a cell contacting unit as described above, which is plugged or can be plugged together in an electrically contacting manner with the fuel cell stack.

[0024] The features disclosed above can be combined as desired, as long as this is technically possible and they do not contradict each other.

[0025] Other advantageous developments of the invention are characterized in the subclaims or are presented in more detail below together with the description of the preferred embodiment of the invention with reference to the figures.

[0026] They show:

[0027] Fig. 1 is a schematic sectional view of a detail of a first embodiment of a cell contacting unit according to the invention,

[0028] Fig. 2 is a schematic sectional view of a detail of an alternative embodiment of the cell contacting unit according to the invention, in a plug-in position,

[0029] Fig. 3 is a perspective sectional view of a cell contacting unit according to the invention, showing a plurality of contacts formed according to the invention, Fig. 4 is a detailed view of the cavities in which the loop contacts are accommodated and

[0030] Fig. 5 shows a further detailed view of a section of Fig. 4.

[0031] Figures 1 to 5 are schematic examples. Identical reference numerals in the figures indicate identical functional and / or structural features.

[0032] Figure 3 shows a perspective view of a cell contacting unit 100 according to the invention. The cell contacting unit 100 is designed for electrically contacting electrical contact sockets 21 arranged in a plurality of rows or columns in a housing 1 of a fuel cell stack 20, wherein the cell contacting unit 100 has the spring contact elements 11 shown at corresponding positions for this purpose. The spring contact elements 11 extend away from the cell contacting unit 100 in the plug-in direction S (downward in Fig. 3), wherein guide ribs 27 are arranged on the housing 15 of the mating plug device of the fuel cell stack 20, viewed in the plug-in direction S, in order to ensure pre-centering before the actual plug-in process. The reference numeral 22 indicates a guide region for pre-centering the spring contact elements 11.

[0033] Figure 1 shows a schematic embodiment of the invention in the form of a partial section of a schematic sectional view of a cell contacting unit 100 which is connected to a contact device of a fuel cell stack 20, in an assembly position at the end of the plugging process in the fully plugged state.

[0034] The loop-like spring contact elements 11 formed from a wire are initially inserted, at least with their front end 11a (front-side bent section 11a of the wire loop 12), into the contact openings of the contact sockets 21 approximately centrally during mating. Subsequently, the lower loop section of each of the two wire loop sections 12a, 12b of the spring contact elements 11 contacts the edge of the opening areas of the contact cavities of the contact sockets 21 during further mating.

[0035] In the alternative embodiment according to Figure 2, a solution is shown which differs from the first embodiment, in which the contact cavity of the contact socket 21 has a lower widened contact receiving area in which the wire loop can relax elastically to a certain extent by the two wire loop sections (or loop sections 12a, 12b) springing back transversely to the plugging direction S towards the wall of the contact sockets 21.

[0036] The locking principle is explained in more detail in Figures 4 and 5. Shown are the contact cavities 24 of the contact sockets 21, each of which contains a locking means 23, designed as a locking dome. The contact cavities 24 are defined by rounded side walls 26. Figure 5 shows the ramp 25. This is located in the area of ​​the cavity 24 in front of the locking means 23 when viewed in the insertion direction and serves as an inclined sliding bearing plane for the wire loop 12 when inserted into the mating position.

[0037] The side walls 26 serve as lateral counterbearings for the resilient engagement of the wire loop sections 12a, 12b of the wire loop 12. As can be clearly seen in Figures 4 and 5, the wire loop 12 wraps around the dome-like locking means 23 and is fixed thereto against being pulled out of the plug-in position, or the separating force is increased according to the geometry of the locking elements involved.

[0038] The invention is not limited to the preferred embodiments described above. Rather, a number of variants are conceivable that utilize the solution presented even in fundamentally different embodiments.

[0039] *****

Claims

Patent claims 1 . Cell contacting unit (100) of a fuel cell for electrically contacting a contact device, comprising a housing (15), of a fuel cell stack (20) of the fuel cell with electrical contact sockets (21) arranged in one or more rows and / or columns, wherein the cell contacting unit (100) has spring contact elements (11) formed from a wire loop at corresponding positions, which extend away from the cell contacting unit (100) in the plug-in direction (S), wherein the spring contact elements (11) form a preferably needle-eye-shaped wire loop (12), which is elastically compressed when plugged into the contact sockets (21), so that two wire loop sections (12a, 12b) of the wire loop (12) of the spring contact elements (11) are pressed against the contact sockets (21) under spring force transversely to the plug-in direction (S), and wherein the contact sockets (21) locking means (23),which, when inserted, hold or fix the wire loops (12) in their position.

2. Cell contacting unit (100) according to claim 1, characterized in that the contact sockets (21) have a cavity or receiving space (24) corresponding to the shape of the wire loops (12), in which the respective wire loop (12) in the inserted state electrically contacts the contact socket (21) along the entire wire loop sections (12a, 12b).

3. Cell contacting unit (100) according to claim 1 or 2, characterized in that in the inserted state a locking dome, locking lug or projection provided in the region of the cavity by the opening in the wire loop (12) protrudes at least partially or completely.

4. Cell contacting unit (100) according to one of the preceding claims, characterized in that in the region of the cavity (24) in front of the locking means (23) as viewed in the insertion direction, an inclined ramp (25) is provided, which serves as an inclined sliding bearing plane for the wire loop (12) when inserted into the plug-in position.

5. Cell contacting unit (100) according to one of the preceding claims, characterized in that the cavity (24) has rounded side walls (26) as a lateral counter-bearing for the resilient contact of the wire loop sections (12a, 12b) of the wire loop (12).

6. Cell contacting unit (100) according to one of the preceding claims, characterized in that the cavity (24) and / or the locking dome / locking nose are produced by deep drawing.

7. Cell contacting unit (100) according to one of the preceding claims, characterized in that the main component of the spring force, which presses the wire loop (12) of the spring contact elements (11) against a side wall of the contact sockets (21) in the inserted state, acts transversely to the plugging direction (S).

8. Cell contacting unit (100) according to claim 1 or 2, characterized in that when plugging together the spring contact elements (11) of the cell contacting unit with the contact sockets (21) of the fuel cell stack, the wire loop (12) of the spring contact elements (11) are increasingly compressed by the shape of the wire loop (12) during the plugging process.

9. Cell contacting unit (100) according to one of the preceding claims, characterized in that the wire loop (12) is formed from a wire in each case as a closed, elastically deformable wire loop from at least two bent wire loop sections (12a, 12b) running next to one another and a bent section (11a) connecting these and formed at the end on the plug-in side.

10. Cell contacting unit (100) according to one of the preceding claims, characterized in that the spring contact elements (11) initially penetrate, at least with their front end, into the contact openings of the contact sockets (21) when plugged together, are then guided over a sliding bearing plane of an inclined ramp (25) and then the wire loop (12) is pushed over the locking means (23).

11. Contact arrangement consisting of a fuel cell stack with socket contacts (22) and a cell contacting unit (100) according to one of the preceding claims, which is designed to be plugged together with the fuel cell stack in an electrically contacting manner.

12. A fuel cell comprising a fuel cell stack formed with socket contacts (22) and a cell contacting unit (100) according to one of the preceding claims, which is plugged or pluggable together with the fuel cell stack in an electrically contacting manner.

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