Bipolar plate, connection system and fuel cell system
By designing plug receptacles with introduction and retention sections on the bipolar plate, and utilizing expansion angles and protrusion structures, the problem of easy connector detachment is solved, achieving stability and reliability of electrical connection, and reducing manufacturing complexity and cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ROBERT BOSCH GMBH
- Filing Date
- 2024-07-15
- Publication Date
- 2026-04-21
AI Technical Summary
In existing fuel cell stacks, the plug-in connectors are prone to coming loose due to vibration or relative movement, which leads to unstable electrical connection between the battery voltage monitoring system and the bipolar plates, affecting the monitoring and regulation effect.
Design a bipolar plate whose plug receiving portion includes an insertion section and a holding section. The maximum width of the holding section is greater than that of the insertion section, and the plug ring is clamped after insertion by an expansion angle and a protruding structure to prevent it from coming out.
It improves the reliability of the insertion contact points, ensures the stability of the electrical connection under vibration and relative motion conditions, simplifies the manufacturing process, and reduces costs.
Smart Images
Figure CN121909535A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a bipolar plate having the features of independent claim 1, a connection system having the features of independent claim 8, and a fuel cell system having the features of independent claim 11. Background Technology
[0002] As is known in the prior art, fuel cell stacks consist of multiple individual fuel cells connected in series to form a larger composite. For monitoring, controlling, or regulating these systems, it is advantageous to know not only the operating parameters of the entire stack but also the operating parameters of each individual cell within the stack. A so-called CVM system (Cell Voltage Monitor System) is used to measure the voltage or other operating parameters of individual fuel cells within the fuel cell stack.
[0003] To connect the battery to the CVM system contacts, a plug connection is typically used, in which metal pins are introduced into the battery stack.
[0004] This contact establishes a conductive connection between the evaluation electronics of the battery monitoring system and the bipolar plates of the fuel cell stack, enabling the measurement of the battery voltage.
[0005] Due to sealing requirements and accessibility within the vehicle, the plug connector must remain within the battery stack for the entire lifespan of the stack. Therefore, it is essential to reliably prevent the contacts from dislodging from their housing due to vibration or other relative movement. Summary of the Invention
[0006] The aforementioned tasks are accomplished by a bipolar plate having the features of independent claim 1, by a connection system having the features of independent claim 8, and by a fuel cell system having the features of independent claim 11. Other features and details of the invention are given in the dependent claims, the description, and the drawings. The features and details described in conjunction with the bipolar plate according to the invention are also applicable in conjunction with the connection system according to the invention and / or with the fuel cell system according to the invention, and vice versa; therefore, the disclosures regarding various aspects of the invention are always mutually referenced or may be mutually referenced.
[0007] A first aspect of the invention is a bipolar plate for a fuel cell stack in a fuel cell system, the bipolar plate having a first separation plate and a second separation plate, and the bipolar plate having at least one distributor region for distributing reactant gases to an active region. Here, the at least one distributor region has at least one plug receiving portion for a plug contact point of a battery voltage monitoring unit.
[0008] Here, the at least one plug receiving portion has an introduction section for introducing the plug contact, particularly the plug ring, and a retaining section for retaining the plug contact, wherein the retaining section is arranged downstream of the introduction section in the insertion direction of the plug contact, and wherein the maximum introduction width of the introduction section corresponds to a maximum of 100%, preferably a maximum of 99%, more preferably a maximum of 90%, and even more preferably a maximum of 70% of the maximum retaining width of the retaining section. In a particular embodiment, it is also conceivable that the retaining section is smaller than the introduction section.
[0009] Here, the retaining section of the plug receiving part is configured such that the inserted plug contact point contacts the transition area of the retaining section. Particularly advantageously, the plug contact point and the retaining section are designed to apply a clamping force to the plug contact point in the inserted state.
[0010] In this document, the maximum holding width of the holding section is understood as the maximum extension of the holding section along the width of the bipolar plate. Correspondingly, the maximum entry width of the entry section corresponds to the maximum extension of the entry section along the width of the bipolar plate. To ensure reliable retention of the plug contact or plug ring in the plug receiver, the maximum holding width of the holding section is greater than the maximum entry width of the entry section.
[0011] There is a transition section between the holding section and the introducing section. It is particularly advantageous here that the holding section expands within the area of this transition section.
[0012] This is particularly advantageous for the plug ring, because after the plug ring is introduced into the retaining section through the introduction section, it expands, thereby creating a clamping force on the plug ring at the transition section between the retaining section and the introduction section of the plug receiving part due to the narrowing formed therein.
[0013] Therefore, in order to release the plug ring, the clamping force must be overcome, as the plug ring must first be compressed before it can be removed from the plug receiver again. This has a positive impact on the electrical connection behavior between the plug ring and the bipolar plates, as it can prevent or hinder the plug contact from disengaging during vibrations or other relative movements in the fuel cell system, or when a vehicle is operating with the fuel cell system. The clamping force generated at the transition between the introduction and holding sections must be overcome to remove the plug contact from the plug receiver, thereby releasing the electrical connection.
[0014] The plug receiver can be manufactured particularly simply because the separator plate used for bipolar plates is stamped, and the plug receiver can be stamped into the separator plate as a recess during the general stamping process.
[0015] This plug housing, with its introduction and retention sections, not only positively impacts the safety of the electrical connections to be or to be generated, but also positively impacts the cost and general functionality of the fuel cell.
[0016] In order to introduce the plug ring into the introduction section of the plug receiver, the plug receiver is configured to have an opening so that the plug ring can be introduced.
[0017] Within the scope of this invention, it may be advantageous for the retaining section of the plug receiving portion to have a circular, elliptical, quadrilateral, or polygonal base surface.
[0018] It can be envisioned that the base plane of the retaining section, in combination with the base plane of the introducing section, has a basic spoon-shaped form. This allows for a particularly simple fulfillment of the criterion that the maximum retaining width of the retaining section is greater than the maximum introducing width of the introducing section.
[0019] By utilizing these shapes of the base surface of the retaining section, it is particularly easy to configure the maximum retaining width of the retaining section to be greater than the maximum width of the introducing section, and at the same time, it is easy to produce by the stamping process without introducing additional force into the bipolar plate.
[0020] Within the scope of the invention, it is conceivable that the retaining section of the plug receiving portion has at least one expansion portion, wherein the expansion portion has an expansion angle of 1° to 80°, preferably 10° to 60°, and more preferably 15° to 45° relative to the insertion section.
[0021] Here, the expansion angle can be viewed from either the central axis or the longitudinal axis of the plug receiving portion. The longitudinal axis can then extend along the length of the bipolar plate, which corresponds to the maximum extension of the bipolar plate.
[0022] Therefore, it is advantageous to maintain the mirror symmetry of the retaining section or general plug receiving portion about the longitudinal axis of the plug receiving portion. This ensures that the plug contact point or plug ring can be retained on both sides by means of the same clamping force.
[0023] Within the scope of this invention, the insertion section of the plug receiving portion may be configured to have a rectangular or trapezoidal base surface.
[0024] It is particularly important to note that the maximum width of the introduction section is less than the maximum width of the retention section. A trapezoidal base has proven particularly advantageous. Here, the parallel sides of the trapezoid are arranged such that one side serves as an opening for introducing the plug ring into the introduction section, while the other side is positioned in the transition region between the retention section and the introduction section. It is particularly advantageous that the smaller of the two parallel sides of the trapezoid corresponds to the transition region. This allows the plug or plug ring to be introduced into the introduction section particularly easily through the wider opening, while simultaneously generating a sufficiently large retaining or clamping force at the transition with the retention section.
[0025] Furthermore, it is conceivable that the first or second separation plate has a protrusion in the base surface of the retaining section of the plug receiving portion.
[0026] The protrusion can be easily created during the stamping process because it only needs to be set in the stamping die of the bipolar plate.
[0027] The protrusions in the retaining section base serve as additional safety protection to prevent the plug or plug ring from coming off or loosening from the plug receiver due to vibration and relative movement.
[0028] When the plug or plug ring is introduced into the retaining section via the introduction section, the plug contact or plug ring is pushed over the protrusion. This means that in the event of vibration or other relative movement, not only the clamping force but also the insertion resistance over the protrusion must be overcome to release or disengage the plug. Therefore, this improves the safety of preventing the plug or plug ring from loosening or disengaging from the plug receiver in a simple way during fuel cell system operation.
[0029] It can also be envisioned that the protrusions in the base surface of the retaining section of the plug receptacle are symmetrical or asymmetrical. In this text, symmetry is understood as a protrusion shaped like a truncated sphere (Kugelkalotte). Asymmetry means that the protrusion has a basic circular or elliptical shape, and that the slope of the protrusion is asymmetrically configured in the insertion direction and the withdrawal direction opposite to the insertion direction. Advantageously, the slope of the protrusion in the insertion direction of the plug contact or plug ring is less than the slope in the withdrawal direction of the plug contact. Therefore, the resistance or force required for insertion of the plug contact is less than the resistance or force required for disengagement or release of the plug contact.
[0030] Therefore, by changing the slope of the bulge in the base of the holding section, the force can be matched according to the direction of movement.
[0031] It is also conceivable that an undercut could be created, allowing the protrusion to function as a hook shape.
[0032] Optionally, within the scope of the invention, the protrusion height of the protrusion in the base surface of the retaining section corresponds to 5% to 100% of the separation plate height of the first separation plate or the separation plate height of the second separation plate, preferably 10% to 80%, and more preferably 15% to 50%.
[0033] The height of the protrusion allows for easy adjustment of resistance during insertion and disengagement.
[0034] A second aspect of the invention is a connection system for a fuel cell system, the connection system having at least one plug contact of a battery voltage monitoring unit and at least one bipolar plate according to a first aspect of the invention. Here, the plug contact is a plug ring that is inserted into a plug receiving portion of the bipolar plate. Here, the maximum ring width of the plug ring in the holding section corresponds to at least 105%, preferably at least 110%, and more preferably at least 115% of the maximum introduction width of the introduction section of the plug receiving portion.
[0035] This is particularly advantageous because the plug ring expands within the holding section or can expand due to the geometry of the plug receiving portion. This expansion of the plug ring, or the fact that the maximum ring width is greater than the maximum insertion width of the insertion section, allows for a simple configuration and ensures the retention or connection of the battery voltage monitoring unit within the bipolar plates.
[0036] Furthermore, within the scope of this invention, the plug ring section may be configured to contact the retaining section in the transition region.
[0037] Here, the retaining area and the corresponding plug ring are designed to apply a clamping force to the plug ring in the transition area. This ensures, in a simple way, that an electrical connection is established and can be established, and that the plug ring will not loosen from the plug receiver due to vibration and relative movement, or can only be loosened by overcoming the clamping force.
[0038] Regarding the present invention, it is conceivable that the plug ring is pushed over the protrusion of the first or second separating plate while in the holding position.
[0039] When inserting the plug ring into the plug receiver, the resistance generated by the narrow insertion section must first be overcome. To further improve or optimize retention, the plug ring needs to be pushed over the protrusion. This additional resistance during plug ring insertion leads to increased resistance when the ring loosens or disengages due to vibration and other relative movements. The retaining position of the plug ring behind the protrusion thus provides greater security, ensuring that the plug ring will not loosen from the plug receiver due to vibration and other relative movements.
[0040] A third aspect of the invention is a fuel cell system having a fuel cell stack having a plurality of bipolar plates according to a first aspect of the invention, and the fuel cell having a voltage monitoring unit having a plurality of plug contacts, wherein the bipolar plates and plug contacts are connected by a connection system according to a second aspect of the invention.
[0041] The advantages described in detail for the bipolar plate according to the first aspect of the invention also apply to the connection system according to the second aspect of the invention and the fuel cell system according to the third aspect of the invention. Attached Figure Description
[0042] Other advantages, features, and details of the invention are set forth in the following description, in which various embodiments of the invention are described in detail with reference to the accompanying drawings. Here, the features mentioned in the claims and specification are important to the invention, either individually or in any combination. The invention is illustrated in the following drawings: Figure 1 A schematic top view of a bipolar plate, showing a plug receiving portion or multiple plug receiving portions. Figure 2 A partial schematic top view of the plug receiving portion of the bipolar plate. Figure 3 A partial schematic cross-sectional view of the plug receiving portion of the bipolar plate. Figure 4 Schematic top view of the connection system for a fuel cell system. Figure 5 A schematic cross-sectional view of a fuel cell system. Detailed Implementation
[0043] exist Figures 1 to 3 The bipolar plate is shown here. Figure 2 and Figure 3 The one in the middle is Figure 1 The part shown.
[0044] according to Figure 1 The bipolar plate 10 of the fuel cell stack 12 for the fuel cell system 14 has a first separation plate 16 and a second separation plate 18. The bipolar plate 10 is formed by assembling the first separation plate 16 and the second separation plate 18 together. Here, the bipolar plate 10 has at least one distributor region 20 for distributing the reactant gases in the active region 22. Here, in the application of the bipolar plate, the reaction of the supplied gases, especially air and hydrogen, on the proton exchange membrane occurs in the active region 22. The at least one distributor region 20 has at least one plug receiving portion 24 for the plug contact 26 of the battery voltage monitoring unit 30.
[0045] The at least one plug receiving portion 24 is here divided into an introduction section 32 for introducing the plug contact 26, and in particular the plug ring 28, and a retaining section 34 for retaining the plug contact 26. Here, the retaining section 34 is arranged downstream of the introduction section 32 in the insertion direction 36 of the plug contact 26. The maximum introduction width BE of the introduction section 32 corresponds to a maximum of 100%, preferably a maximum of 990%, more preferably a maximum of 90%, and even more preferably a maximum of 70% of the maximum retaining width BH of the retaining section 34.
[0046] In this embodiment, the maximum introduction width BE of the introduction section 32 corresponds to 90% of the maximum retention width BH of the retention section.
[0047] The retaining section 34 of the plug receiving portion 24 has an elliptical base surface 38. The base surface 38 can also be configured as a circle, a quadrilateral, or a polygon.
[0048] like Figure 2 As can be seen in particular, the retaining section 34 of the plug receiving portion 24 has at least one expansion portion 40. Here, the expansion portion 40 has an expansion angle α. This expansion angle, in this embodiment, is in the range of 1° to 80°, and is relative to the insertion section 32. Figure 2 As can be seen, the expansion section is directly attached to the introduction section. Correspondingly, the retaining section 34 expands immediately from the end of the introduction section 32 to its maximum retaining width BH.
[0049] The insertion section 32 of the plug receiving portion 24 has a rectangular base surface 38. A trapezoidal base surface 38 may also be conceived at this location.
[0050] like Figure 3 As can be seen, the first separating plate 16 has a protrusion 44 in the base surface 38 of the retaining section 34 of the plug receiving portion 24. In an embodiment not shown here, it is also possible that, instead of the first separating plate 16, the second separating plate 18 has a protrusion 44 in the corresponding base surface 38 of the retaining section 34 of the plug receiving portion 24.
[0051] In this embodiment, the protrusion 44 of the base surface 38 of the retaining section 34 is symmetrically configured. This means that the same force needs to be applied whether the plug is being inserted in the insertion direction or being pulled out of the contact point 26 in the opposite direction of insertion.
[0052] Here, the protrusion 44 has a protrusion height HE. The protrusion height HE is between 5% and 100% of the separation plate height H_SP1 of the first separation plate 16. If the protrusion 44 is provided in the second separation plate 18, the protrusion height HE corresponds to 5% to 100% of the separation plate height H_SP2.
[0053] exist Figure 4 The diagram shows a connection system 46 for a fuel cell system 14, the connection system having at least one plug contact 26 of a battery voltage monitoring unit 30 and according to... Figures 1 to 3 At least one bipolar plate 10 as described in one of the embodiments. Here, the insertion contact 26 is configured as a plug ring 28 and is inserted into the plug receiving portion 24 of the bipolar plate 10.
[0054] like Figure 4As can be seen, the maximum loop width BS of the plug ring 28 in the holding section 34 is greater than the maximum lead-in width BE of the lead-in section 32 of the plug receiving portion 24. In the illustrated embodiment, the maximum loop width BS of the plug ring 28 corresponds to at least 105% of the maximum lead-in width BE of the lead-in section 32.
[0055] Here, the plug ring 28 is configured such that it partially contacts the retaining section 34 in a transition region 48. This transition region 48 can also be considered as a transition region between the insertion section 32 and the retaining section 34. This transition region 48 is particularly advantageous when the retaining section 34 has an expansion angle α in this region. Thus, after the plug ring is inserted into the retaining section 34 via the insertion section 32, the plug ring can expand to reach its maximum ring width BS.
[0056] To occupy a particularly reliable position, the plug ring 28 is pushed over the protrusion 44 of the first separation plate 16. Thus, the plug ring 28 is held in its holding position HP not only by the clamping force FK in the transition region 48, but also by the protrusion 44, thereby preventing it from coming off due to vibration or other relative motion during operation of the fuel cell or fuel cell stack.
[0057] exist Figure 5 The diagram shows a fuel cell system 14, which has a fuel cell stack 12 with multiple bipolar plates 10. In addition, the fuel cell system 14 has a battery voltage monitoring unit 30 with multiple insertion contacts 26. Figure 4 As shown, the bipolar plate 10 and the plug contact 26 of the voltage monitoring unit 30 are interconnected through the connection system 46.
[0058] This ensures that the electrical connection between the plug contact 26 and the multiple bipolar plates 10 of the fuel cell stack 12 is maintained during operation, thereby ensuring monitoring of the fuel cell stack 12.
Claims
1. A bipolar plate (10) for a fuel cell stack (12) in a fuel cell system (14). The bipolar plate has a first separation plate (16) and a second separation plate (18), and the bipolar plate has at least one distributor region (20) for distributing the reactant gas into the active region (22), wherein, The at least one distributor region (20) has at least one plug receiving portion (24) for the plug contact (26) of the battery voltage monitoring unit (30). Its features are, The at least one plug receiving portion (24) has an introduction section (32) for introducing the plug contact (26), in particular the plug ring (28), and a retaining section (34) for retaining the plug contact (26), wherein the retaining section (34) is arranged downstream of the introduction section (32) in the insertion direction (36) of the plug contact (26), and wherein the maximum introduction width (BE) of the introduction section (32) corresponds to a maximum of 100%, preferably a maximum of 99%, preferably a maximum of 90%, and more preferably a maximum of 70% of the maximum retaining width (BH) of the retaining section (34).
2. The bipolar plate (10) according to claim 1. Its features are, The retaining section (34) of the plug receiving portion (24) has a circular, elliptical, quadrilateral, or polygonal base surface (38).
3. The bipolar plate (10) according to claim 1 or 2. Its features are, The retaining section (34) of the plug receiving portion (24) has at least one expansion portion (40), wherein the expansion portion (40) has an expansion angle (α) of 1° to 80°, preferably 10° to 60°, and more preferably 15° to 45° relative to the introduction section (32).
4. The bipolar plate (10) according to any one of the preceding claims. Its features are, The insertion section (32) of the plug receiving portion (24) has a rectangular or trapezoidal base surface (42).
5. The bipolar plate (10) according to any one of the preceding claims. Its features are, The first separation plate (16) or the second separation plate (18) has a protrusion (44) in the base surface (38) of the retaining section (34) of the plug receiving portion (24).
6. The bipolar plate (10) according to claim 5. Its features are, The protrusions (44) in the base surface (38) of the retaining section (34) of the plug receiving portion (24) are symmetrical or asymmetrical.
7. The bipolar plate (10) according to claim 5 or 6. Its features are, The height (HE) of the protrusion (44) in the base surface (38) of the retaining section (34) is 5% to 100% of the separation plate height (H_SP1) of the first separation plate (16) or the separation plate height (H_SP2) of the second separation plate (18), preferably 10% to 80%, and more preferably 15% to 50%.
8. A connection system (46) for a fuel cell system (14), the connection system having at least one plug contact (26) of a battery voltage monitoring unit (30) and at least one bipolar plate (10) according to any one of the preceding claims, wherein, The insertion contact (26) is a plug ring (28) that is inserted into the plug receiving portion (24) of the bipolar plate (10), wherein the maximum ring width (BS) of the plug ring (28) in the holding section (34) corresponds to at least 105%, preferably at least 110%, and more preferably at least 115% of the maximum lead width (BE) of the lead section (32) of the plug receiving portion (24).
9. The connection system (46) according to claim 8. Its features are, The plug ring (28) is in contact with the retaining section (34) in the transition region (48).
10. The connection system (46) according to claim 8 or 9. Its features are, The plug ring (28) is pushed over the protrusion (44) of the first separation plate (16) or the second separation plate (18) in the holding position (HP).
11. A fuel cell system (14) having a fuel cell stack (12) having a plurality of bipolar plates (10) according to any one of claims 1 to 7, and the fuel cell system having a battery voltage monitoring unit (30) having a plurality of plug contacts (26), wherein, The bipolar plate (10) and the insertion contact (26) are connected by a connection system (46) according to any one of claims 8 to 10.