Electric pile press-fitting device and press-fitting method thereof

Abstract

The invention relates to the technical field of fuel cell stack press-fitting, and particularly discloses a stack press-fitting device and a press-fitting method.The stack press-fitting device comprises a connecting base and a plurality of floating pressing blocks, the connecting base is provided with a pressure cavity and a connector communicated with the pressure cavity, and the connector is used for inputting compressed gas into the pressure cavity; the pressure cavity comprises a communicating cavity and a plurality of branch cavities communicating with the communicating cavity. One ends of the plurality of floating pressing blocks are slidably arranged in the plurality of sub-chambers in a one-to-one correspondence manner, and the other end of each floating pressing block extends out of the corresponding sub-chamber and is used for applying a pressing force to the fuel cell stack to be packaged, so that the plurality of fuel cell stacks can be synchronously packaged through the plurality of floating pressing blocks to ensure the operation efficiency; and the method can adapt to the condition that the actual packaging heights of different fuel cell stacks are different due to part machining errors, it can be guaranteed that the packaging force on all the fuel cell stacks is equal, and the quality stability of packaged finished products is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell stack press-assembly, and in particular to a fuel cell stack press-assembly device and a press-assembly method thereof. Background Art

[0002] A fuel cell is a device that converts the chemical energy of reactants into electrical energy. It boasts high power generation efficiency, minimal environmental pollution, high specific energy, and high reliability. A fuel cell stack is composed of core components such as end plates, insulating plates, current collectors, bipolar plates, and membrane electrodes, stacked one by one. During the fuel cell stack packaging process, it is typically assembled using a stack press.

[0003] In the prior art, most stack pressing devices usually only press-fit one fuel cell stack, while some can press-fit multiple fuel cell stacks at the same time. For example, the solution disclosed in the previous patent application number CN202311439892.0 presses multiple fuel cell stacks one by one by sliding multiple pressing heads set on the frame. Each pressing head is also provided with a bolt, which is threadedly connected to the frame. The bolt is used to tighten the pressing head to adjust the packaging force of the pressing head corresponding to the fuel cell stack, thereby achieving independent pressing of multiple fuel cell stacks. However, due to the existence of component processing errors, the height of the finished product after pressing different fuel cell stacks will vary, which in turn causes the height of each pressing head to be adjusted separately when pressing the fuel cell stack, affecting the pressing efficiency. In addition, the packaging force of each pressing head is adjusted by bolts, and the adjustment accuracy is poor, affecting the packaging quality of the finished fuel cell stack. Summary of the Invention

[0004] The purpose of the present invention is to provide a fuel cell stack press-assembly device and a press-assembly method thereof, so as to improve the press-assembly efficiency when press-assembling multiple fuel cell stacks and the packaging quality of the finished fuel cell stack after packaging.

[0005] In one aspect, the present invention provides a battery stack press assembly device, comprising:

[0006] A connecting seat, wherein the connecting seat is provided with a pressure chamber and an interface communicating with the pressure chamber, the interface being used to input compressed gas into the pressure chamber, the pressure chamber comprising a communicating chamber and a plurality of sub-chambers communicating with the communicating chamber;

[0007] A plurality of floating pressure blocks are arranged in a one-to-one correspondence with the plurality of sub-chambers, one end of the floating pressure block is slidably located in the sub-chamber, and the other end of the floating pressure block extends out of the sub-chamber and is used to apply a compressive force to the fuel cell stack.

[0008] As a preferred technical solution of the battery stack press-assembly device, the battery stack press-assembly device further includes a pressure gauge, which is used to detect the pressure of the gas in the pressure chamber.

[0009] As an optimal technical solution for the battery stack pressing device, the battery stack pressing device also includes a plurality of limit brackets, each of which is detachably connected to the connecting seat, and the plurality of limit brackets are arranged in a one-to-one correspondence with the plurality of floating pressure blocks, and the limit brackets are provided with a plurality of avoidance holes, and the plurality of avoidance holes are all connected to the sub-chambers; the floating pressure block includes a pressure block body and a plurality of pressure heads, and the plurality of pressure heads are arranged at intervals in the pressure block body, and the pressure block body can be slidably located in the corresponding sub-chamber, and the plurality of pressure heads are passed through the plurality of avoidance holes in a one-to-one correspondence, and the pressure block body can abut against the limit bracket.

[0010] As a preferred technical solution of the stack press-assembly device, the floating pressure block further includes a first sealing ring sleeved on the pressure block body, and the first sealing ring is sealed and fitted with the pressure block body and the cavity wall of the sub-chamber respectively.

[0011] As an optimal technical solution for the battery stack pressing device, the connecting seat includes a main seat body, a cover plate and a second sealing ring. The main seat body and the cover plate are detachably connected, and the main seat body and the cover plate are arranged to form the pressure chamber. The second sealing ring is arranged between the main seat body and the cover plate, and the second sealing ring is sealed and fitted with the main seat body and the cover plate respectively.

[0012] As a preferred technical solution of the battery stack press-assembly device, the battery stack press-assembly device further includes a quick-connect connector installed at the interface, and the quick-connect connector is used to connect to an external gas source.

[0013] The battery stack press assembly device provided by the present invention has at least the following beneficial effects:

[0014] The fuel cell stack pressing device includes a connecting seat and multiple floating pressure blocks. The connecting seat is provided with a pressure chamber and an interface connected to the pressure chamber. The interface is used to input compressed gas into the pressure chamber. The pressure chamber includes a connecting chamber and multiple sub-chambers connected to the connecting chamber. The multiple floating pressure blocks are arranged in a one-to-one correspondence with the multiple sub-chambers. One end of the floating pressure block is slidably located in the sub-chamber, and the other end of the floating pressure block extends out of the sub-chamber and is used to apply a pressing force to the fuel cell stack. The fuel cell stack pressing device has a connecting seat for connecting to a press. By filling a pressure chamber with compressed gas, the pressure provided by the press is transmitted to each floating pressure block through the pressure chamber, and then multiple fuel cell stacks can be pressed one by one by multiple floating pressure blocks, so that multiple fuel cell stacks can be packaged simultaneously to ensure operation efficiency; since the floating pressure blocks can slide in the sub-chambers, they can adapt to the situation where there are differences in the actual packaging heights of different fuel cell stacks caused by component processing errors; in addition, since the pressure of the press is distributed to each floating pressure head by the compressed gas in the pressure chamber, and then the packaging force is provided to the fuel cell stack to be packaged by the floating pressure head, it can ensure that the packaging force on each fuel cell stack is equal, thereby ensuring the stable quality of the finished fuel cell stack.

[0015] In another aspect, the present invention provides a method for pressing a battery stack press assembly device, which is implemented by the battery stack press assembly device in any of the above schemes, and the method for pressing a battery stack press assembly device comprises:

[0016] Obtain the design parameters of the fuel cell stack to be packaged and the stack pressing device, the design parameters of the fuel cell stack to be packaged and the stack pressing device include: the packaging force F of the fuel cell stack to be packaged s , the area S1 of the floating pressure block that bears the compressed gas pressure, the maximum sliding distance D of the floating pressure block s , the maximum difference in the design height of the fuel cell stack △H, and the maximum effective volume V1 of the pressure chamber;

[0017] Determine the initial pressure P0 of the compressed gas to be filled into the pressure chamber based on the design parameters of the fuel cell stack to be packaged and the stack press assembly device;

[0018] Obtain the current production cycle t and the current leakage mass flow Q of the pressure chamber of the stack press assembly device;

[0019] Determine the correction factor m based on t and Q;

[0020] Determine the actual pressure P1 of the compressed gas to be filled into the pressure chamber based on m and P0;

[0021] The stack pressing device is installed on the press, and compressed gas with a pressure value of P1 is filled into the pressure chamber, and the fuel cell stack is packaged.

[0022] As a preferred technical solution for the press-assembly method of the stack press-assembly device, determining the initial pressure P0 of the compressed gas to be filled into the pressure chamber based on the design parameters of the fuel cell stack to be packaged and the stack press-assembly device includes:

[0023] Judgment (V1F s -△HS1) / (V1-2D s S1) is greater than the square of the set sealing performance coefficient e; if so, the relationship between the design parameters of the fuel cell stack to be packaged and the stack press-fitting device and the initial pressure P0 of the compressed gas to be filled in the pressure chamber is:

[0024] (V1F s -2D s S1F s ) / (S1V1)≤P0≤(V1F s -△HS1F s ) / (S1V1).

[0025] As a preferred technical solution for the press-assembly method of the stack press-assembly device, the formula for determining the correction coefficient m based on T1 and Q is:

[0026] m=1+(T0QtR) / (P0V1M)+a;

[0027] Wherein, T0 is the preset ambient temperature, R is Avogadro's constant, M is the molar mass of the filled gas, and a is a constant.

[0028] As a preferred technical solution of the press-assembly method of the fuel cell stack press-assembly device, the compressed gas with a pressure value of P1 is filled into the pressure chamber, and the fuel cell stack is packaged, including:

[0029] When the fuel cell is packaged for the first time during the production cycle, the pressure of the compressed gas filled into the pressure chamber is P1 = P max , P max =(V1F s -△HS1F s ) / (S1V1m);

[0030] When the fuel cell is packaged for the nth time during the production cycle, the actual pressure P2 of the compressed gas in the pressure chamber is obtained, and the difference between P2 and P min The size of P min =m(V1F s -2D s S1F s ) / (S1V1), n ​​is an integer greater than 1;

[0031] If P2≥P min ; Then directly encapsulate, if P2<P min; Then the compressed gas is added to the pressure chamber, and the pressure of the compressed gas P1=P max .

[0032] The present invention provides a method for pressing a battery stack, which has at least the following beneficial effects:

[0033] The pressing method of the stack pressing device obtains the design parameters of the fuel cell stack to be packaged and the stack pressing device, and determines the initial pressure P0 of the compressed gas to be filled in the pressure chamber based on the design parameters of the fuel cell stack to be packaged and the stack pressing device; obtains the actual ambient temperature T1, the current production cycle t and the current leakage mass flow Q of the pressure chamber of the stack pressing device; determines the correction coefficient m based on T1, t and Q; determines the actual pressure P1 of the compressed gas to be filled in the pressure chamber based on m and P0, P1=mP0; installs the stack pressing device on the press, and fills the pressure chamber with compressed gas with a pressure value of P1, and packages the fuel cell stack, which can ensure that the actual pressure of the compressed gas to be filled in the pressure chamber is reliable, thereby ensuring the reliable pressing quality of the fuel cell stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the structure of the battery stack press assembly device in an embodiment of the present invention;

[0035] Figure 2 This is an exploded view of a battery stack press-assembly device according to an embodiment of the present invention;

[0036] Figure 3 A cross-sectional view of a battery stack press-assembly device according to an embodiment of the present invention;

[0037] Figure 4 Schematic diagram of the structure of the stack press-assembly device during press-assembly operation according to an embodiment of the present invention;

[0038] Figure 5 Flowchart of the press-assembly method of the battery stack press-assembly device in an embodiment of the present invention.

[0039] In the picture:

[0040] 100, fuel cell stack press assembly device; 200, press machine; 300, fuel cell stack; 310, end plate;

[0041] 1. Connecting seat; 11. Pressure chamber; 111. Connecting chamber; 112. Sub-chamber; 12. Interface; 13. Main seat body; 14. Cover plate; 15. Second sealing ring; 16. Second bolt;

[0042] 2. Floating pressure block; 21. Pressure block body; 22. Pressure head; 23. First sealing ring;

[0043] 3. Pressure gauge;

[0044] 4. Limit bracket; 41. Avoidance hole;

[0045] 5. First bolt; 6. Quick-connect connector. DETAILED DESCRIPTION

[0046] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0047] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature being "above", "above" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature includes the first feature being directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0048] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0049] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0050] Example 1

[0051] Existing fuel cell stack press-fitting devices use multiple pressing heads that slide onto a frame to press-fit multiple fuel cell stacks one by one. Each pressing head is also provided with a bolt that is threadedly connected to the frame. The bolt is used to tighten the pressing head to adjust the sealing force of the pressing head corresponding to the fuel cell stack, thereby achieving independent press-fitting of multiple fuel cell stacks. However, due to machining errors of components, the height of the finished fuel cell stacks after press-fitting can vary. This results in the need to adjust the height of each pressing head individually when press-fitting the fuel cell stack, affecting press-fitting efficiency. Furthermore, the sealing force of each pressing head is adjusted using bolts, resulting in poor adjustment accuracy, which affects the sealing quality of the finished fuel cell stack.

[0052] To this end, this embodiment provides a fuel cell stack press assembly device to solve the above-mentioned problem.

[0053] Please refer to Figures 1 to 4 The fuel cell stack press-assembly device 100 includes a connection base 1 and a plurality of floating pressure blocks 2. The connection base 1 is provided with a pressure chamber 11 and an interface 12 communicating with the pressure chamber 11. The interface 12 is used to connect to an external gas source and input compressed gas into the pressure chamber 11. The pressure chamber 11 includes a connecting chamber 111 and a plurality of sub-chambers 112 communicating with the connecting chamber 111. The plurality of floating pressure blocks 2 are arranged in a one-to-one correspondence with the plurality of sub-chambers 112. One end of the floating pressure block 2 is slidably positioned within the sub-chamber 112, while the other end of the floating pressure block 2 extends out of the sub-chamber 112 and is used to apply a compressive force to the fuel cell stack 300 to be packaged. The fuel cell stack pressing device 100, the connecting seat 1 is used to be connected to the press 200. By filling the pressure chamber 11 with compressed gas, the pressure provided by the press 200 is transmitted to each floating pressure block 2 through the pressure chamber 11, and then the multiple fuel cell stacks 300 can be pressed one by one by multiple floating pressure blocks 2, so that the multiple fuel cell stacks 300 can be packaged simultaneously to ensure operation efficiency; because the floating pressure blocks 2 can slide in the sub-chamber 112, they can adapt to the situation where there are differences in the actual packaging heights of different fuel cell stacks 300 caused by component processing errors; in addition, because the pressure of the press 200 is distributed to each floating pressure head 22 by the compressed gas in the pressure chamber 11, and then the floating pressure head 22 provides packaging force to the fuel cell stack 300 to be packaged, it can ensure that the packaging force on each fuel cell stack 300 is equal, thereby ensuring the stable quality of the finished fuel cell stack 300.

[0054] Specifically, after the connecting seat 1 is installed on the press 200, the press 200 can drive the mounting seat to move synchronously, and enable each floating pressure block 2 to pressurize the corresponding end plate 310 of the fuel cell stack 300 to be packaged. The pressure provided by the press 200 acts on each floating pressure block 2 through the compressed gas in the pressure chamber 11, and is then distributed to the end plate 310 of each fuel cell stack 300.

[0055] It is understandable that in this embodiment, the structures of the floating pressure blocks 2 are identical, that is, the surface areas of the floating pressure blocks 2 located in the pressure chamber 11 are identical, so that the pressure exerted by the compressed gas in the pressure chamber 11 on the floating pressure blocks 2 is equal, ensuring that the packaging forces of the fuel cell stacks 300 are equal during packaging.

[0056] Optionally, the sub-chamber 112 is square in shape to prevent the floating pressure head 22 from rotating when pressurizing the fuel cell stack 300 to be packaged.

[0057] Optionally, the compressed gas may be compressed air, nitrogen, etc. Preferably, some liquid may also be mixed into the compressed gas.

[0058] Optionally, the battery stack pressing device 100 also includes a pressure gauge 3, which is used to detect the pressure of the gas in the pressure chamber 11. Through the reading of the pressure gauge 3, it can be determined whether the pressure of the compressed gas in the pressure chamber 11 is stable, and whether it is necessary to refill the compressed gas into the pressure chamber 11.

[0059] Optionally, the stack press-assembly device 100 further includes a plurality of limiting brackets 4, each of which is detachably connected to the connecting seat 1. The plurality of limiting brackets 4 are arranged in a one-to-one correspondence with the plurality of floating pressure blocks 2. The limiting brackets 4 are provided with a plurality of avoidance holes 41, and the plurality of avoidance holes 41 are all connected to the sub-chamber 112. The floating pressure blocks 2 include a pressure block body 21 and a plurality of pressure heads 22, the plurality of pressure heads 22 being arranged at intervals on the pressure block body 21. The pressure block body 21 is slidably positioned within the corresponding sub-chamber 112. The plurality of pressure heads 22 are correspondingly provided in the plurality of avoidance holes 41, and the pressure block body 21 can abut against the limiting brackets 4. In this arrangement, each floating pressure block 2 simultaneously pressurizes the fuel cell stack 300 through the plurality of pressure heads 22, ensuring balanced force, and the floating pressure blocks 2 are separated from the sub-chamber 112 by the limiting brackets 4. Specifically, in this embodiment, the pressure head 22 is clearance-matched with the avoidance hole 41 , and the limiting bracket 4 and the connecting seat 1 are detachably connected by a plurality of first bolts 5 .

[0060] As an alternative, the sub-chamber 112 can be set as a stepped hole, which includes a first hole and a second hole interconnected with each other, the aperture of the first hole is larger than the aperture of the second hole, and the floating pressure head 22 is also set to be stepped. The floating pressure head 22 can abut against the steps of the stepped hole, which can also prevent the floating pressure head 22 from falling off from the sub-chamber 112.

[0061] Optionally, the floating pressure block 2 further includes a first sealing ring 23 sleeved on the pressure block body 21, and the first sealing ring 23 is respectively sealed against the pressure block body 21 and the cavity wall of the sub-chamber 112. Such a configuration can improve the sealing of the pressure chamber 11 and reduce the leakage of compressed gas in the pressure chamber 11. Specifically, an annular first sealing groove is provided on the outer peripheral surface of the pressure block body 21, and the first sealing ring 23 is provided in the first sealing groove, and the first sealing ring 23 can be sealed against the cavity wall of the sub-chamber 112. In other embodiments, a first sealing groove can also be provided on the cavity wall of the sub-chamber 112, and the first sealing ring 23 is sealed against the outer peripheral surface of the pressure block body 21.

[0062] Optionally, the connecting seat 1 includes a main seat body 13, a cover plate 14, and a second sealing ring 15. The main seat body 13 and the cover plate 14 are detachably connected, and the main seat body 13 and the cover plate 14 enclose a pressure chamber 11. The second sealing ring 15 is arranged between the main seat body 13 and the cover plate 14, and the second sealing ring 15 is sealed and fitted with the main seat body 13 and the cover plate 14 respectively. Such an arrangement can further improve the sealing of the pressure chamber 11 and further reduce the leakage of compressed gas in the pressure chamber 11. Specifically, the main seat body 13 is a cavity and has an opening connected to the outside world. The cover body closes the opening and then encloses the pressure chamber 11 with the main seat body 13. The main seat body 13 is provided with an annular second sealing groove, and the second sealing groove is arranged around the opening. The second sealing ring 15 is arranged in the second sealing groove, and the second sealing ring 15 can be sealed and fitted with the cover plate 14. In other embodiments, a second sealing groove may be provided in the cover plate 14 , and the second sealing ring 15 is sealed and fitted with the main seat body 13 .

[0063] Optionally, the cover plate 14 and the main seat body 13 are detachably connected via a plurality of second bolts 16. In other embodiments, a sealed threaded connection may also be used.

[0064] Optionally, the battery stack pressing device 100 also includes a quick-insert connector 6 installed at the interface 12, which is used to connect to an external gas source. In this way, the quick-insert connector 6 is convenient for quick plugging and unplugging with the air pipe of the external gas source, and is easy to operate. Preferably, a tapered internal thread is provided at the interface 12, and the quick-insert connector 6 is provided with a tapered external thread, so that the quick-insert connector 6 is threadedly connected to the connecting seat 1 and can ensure sealing. It should be noted that the quick-insert connector 6 can also be used to release the compressed gas in the pressure chamber 11.

[0065] Example 2

[0066] This embodiment provides a press-assembly method of a battery stack press-assembly device, which is implemented by the battery stack press-assembly device of one of the above embodiments.

[0067] For details, please refer to Figure 5 The press-assembly method of the stack press-assembly device includes the following steps:

[0068] S100: Obtain design parameters of a fuel cell stack to be packaged and a stack pressing device.

[0069] In this embodiment, the design parameters of the fuel cell stack to be packaged and the stack press assembly device include: the packaging force F of the fuel cell stack to be packaged s , the area S1 of the floating pressure block that bears the compressed gas pressure, the maximum sliding distance D of the floating pressure block s , the maximum difference in the design height of the fuel cell stack △H, and the maximum effective volume V1 of the pressure chamber.

[0070] Among them, the packaging force F of the fuel cell stack to be packaged s It can be determined based on the specific model of the fuel cell stack to be packaged; the area S1 of the floating pressure block under the pressure of the compressed gas is also the area of ​​action between the floating pressure block and the compressed gas in the pressure chamber; the floating pressure block slides in the sub-chamber and has an extreme position when extended and an extreme position when retracted, and the maximum sliding distance D s The maximum effective volume V1 of the pressure chamber is the volume of the remaining space within the pressure chamber when all floating pressure blocks are at their extended extreme positions within the sub-chambers.

[0071] S200: Determine the initial pressure P0 of the compressed gas to be filled into the pressure chamber based on the design parameters of the fuel cell stack to be packaged and the stack press assembly device.

[0072] Among them, the design parameters of the fuel cell stack to be packaged and the stack pressing device can be input into a predetermined initial pressure model, and the initial pressure model outputs the initial pressure P0. The initial pressure model can be a deep learning model or a mathematical model that reflects the relationship between the design parameters and initial pressure of the fuel cell stack to be packaged and the stack pressing device. This embodiment does not limit the initial pressure model, as long as the initial pressure of the compressed gas to be filled can be determined based on the design parameters of the fuel cell stack to be packaged and the stack pressing device.

[0073] Specifically, in this embodiment, the initial pressure model takes a mathematical model as an example, and the process of determining the initial pressure model is as follows:

[0074] Judgment (V1F s -△HS1) / (V1-2D sIs the value of S1 greater than the square of the set sealing performance coefficient e?

[0075] If so, the relationship between the design parameters of the fuel cell stack to be packaged and the stack press-fitting device and the initial pressure P0 of the compressed gas to be filled in the pressure chamber is: (V1F s -2D s S1F s ) / (S1V1)≤P0≤(V1F s -△HS1F s ) / (S1V1); If not, the sealing of the pressure chamber of the stack pressing device needs to be maintained.

[0076] Specifically, the derivation process of the model is as follows:

[0077] 1) When the pressure chamber is filled with gas with a pressure of P0, the pressure of the floating pressure block is F1, which is equal to the product of P0 and S1, and F1<F S , so P1<F S / S1(Formula 1).

[0078] 2) Take the case of two floating pressure blocks as an example. Initially, both floating pressure blocks are at their extended limit positions. When the fuel cell stack to be packaged is packaged, the two floating pressure blocks retract inwards. The final retracted distances of the two floating pressure blocks are marked as D1 and D2 (assuming D1≥D2). Then D1+D2≤2D S (Formula 2).

[0079] 3) After press-fitting, the final gas pressure in the pressure chamber is P n , then according to the gas equation, the product of the volume and pressure of the pressure chamber before and after pressing is equal, so P0V1=P n [V1-(D1+D2)S1](Formula 3).

[0080] 4) After press-fitting, the packaging force of the fuel cell stack to be packaged is equal to the pressure of the gas in the pressure chamber after press-fitting given to the floating pressing block, then P n S1=F S (Formula 4).

[0081] 5) The stack press-fitting device can match the height differences of different fuel cell stacks. Therefore, assuming that only one floating pressing block moves, it must be greater than △H, so D1+D2≥△H (Formula 5).

[0082] The initial pressure model can be determined by the above five formulas as follows: (V1F s -2D s S1F s ) / (S1V1)≤P0≤(V1Fs -△HS1F s ) / (S1V1).

[0083] It should be noted that, due to the actual production process, D s Usually much larger than △H, so (V1F s -2D s S1F s ) / (S1V1) must be greater than (V1F s -△HS1F s ) / (S1V1) should be small to ensure that the above pressure model is valid. However, the above pressure model also reflects the sealing performance of the pressure chamber from the side.

[0084] In addition, the sealing performance of the pressure chamber can be measured by comparing the ratio of the upper limit value to the lower limit value of P0 with the square of the set sealing performance coefficient e (which will be explained in detail below). Specifically, when [(V1F s -△HS1F s ) / (S1V1)] / [(V1F s -2D s S1F s ) / (S1V1)]=(V1F s -△HS1) / (V1-2D s S1)>e 2 When (V1F s -△HS1) / (V1-2D s S1)≤e 2 When the stack pressing device is in a state of failure, it is necessary to perform maintenance on the stack pressing device, such as replacing the sealing ring, etc., indicating that the stack pressing device is not suitable for production. s -2D s S1F s ) / (S1V1)≤P0≤(V1F s -△HS1F s ) / (S1V1) is established on the premise that (V1F s -△HS1) / (V1-2D s S1)>e 2 .

[0085] S300: Obtain the current production cycle t and the current leakage mass flow Q of the pressure chamber of the fuel cell stack press-assembly device.

[0086] Among them, the production cycle is the production interval between two adjacent batches of products, and the current production cycle t can be obtained by analyzing the order data; the pressure of the compressed gas in the pressure chamber of the battery stack pressing device will continue to decrease with the extension of the use time. The current leakage mass flow rate Q of the pressure chamber of the battery stack pressing device can be obtained by filling the pressure chamber with compressed gas with 1.2 times the initial pressure, continuously detecting the gas pressure in the pressure chamber and calculating the difference in gas pressure per unit time, and then determining it based on the difference and the volume of the pressure chamber; or detecting it through a mass flow meter.

[0087] S400: Determine the correction coefficient m based on t and Q.

[0088] Among them, t and Q can be input into a predetermined correction coefficient model, and the correction coefficient model outputs the correction coefficient m. The correction coefficient model can be a deep learning model or a mathematical model that reflects the relationship between t, Q and m. This embodiment does not limit the correction coefficient model, as long as the correction coefficient that needs to be corrected for P0 can be determined based on t and Q.

[0089] In this embodiment, the correction coefficient model takes a mathematical model as an example, and the correction coefficient model is:

[0090] m=1+(T0QtR) / (P0V1M)+a;

[0091] Wherein, T0 is the preset ambient temperature, R is Avogadro's constant, Q is the leakage mass flow rate during the airtightness self-test of the device, M is the molar mass of the filled gas, and a is a constant.

[0092] Specifically, the derivation process of the correction coefficient model is as follows:

[0093] 1) The molar amount of gas leaked from the pressure chamber during the calibration production cycle is Δn, then Δn=Qt / M (Formula 6).

[0094] 2) According to the ideal gas equation, when the volume of the pressure chamber is the maximum effective volume V1, the product of the gas pressure in the pressure chamber and the maximum effective volume before and after correction must be no less than the influence caused by changes in temperature, production cycle, and leakage mass flow rate. Therefore, (m-1)P0V1>T0△nR (Formula 7);

[0095] 3) Through the above formulas 6 and 7, it can be obtained that m>1+(T0QtR) / (P0V1M). In order to further ensure the reliability of the value of m, the value of m can be increased by a on this basis, where a is greater than zero. Specifically, a can be between 0.1 and 0.2, thereby obtaining m=1+(T0QtR) / (P0V1M)+a.

[0096] It should be noted that steps S300 and S400 can be confirmed separately for each production batch, or m can be recorded, and in subsequent production batches, it is determined whether the difference in the current production cycle exceeds the limit, and whether the difference in the current leakage mass flow rate of the pressure chamber of the stack pressing device exceeds the limit. If both differences are within the limit, the value of m is used. If either one exceeds the limit, S300 and S400 need to be performed, which can effectively improve production efficiency. Among them, the difference in the current production cycle is the difference between the current production cycle corresponding to the recorded correction coefficient m and the current production cycle of the subsequent production batch at that time; the difference in the current leakage mass flow rate is the difference between the current leakage mass flow rate corresponding to the recorded correction coefficient m and the current leakage mass flow rate of the subsequent production batch at that time.

[0097] In addition, considering that the sealing performance of the sealing ring will weaken as the number of times it is used increases during actual use, when the sealing performance weakens, that is, when the device is self-checked for airtightness, the leakage mass flow rate will be too large, and m=1+(T0QtR) / (P0V1M)+a; therefore, the value of m will also be too large. In this embodiment, when m>e, it indicates that the sealing performance does not meet the production requirements, and the battery stack pressing device needs to be maintained, such as replacing the sealing ring, etc. When m≤e, it indicates that the sealing performance meets the production requirements and production can be carried out. The ratio of the upper limit value to the lower limit value of P0 [(V1F s -△HS1F s ) / (S1V1)] / [(V1F s -2D s S1F s ) / (S1V1)]=(V1F s -△HS1) / (V1-2D s S1)>m 2 If you want to ensure the sealing of the pressure chamber, you must also ensure (V1F s -△HS1) / (V1-2D s S1)>e 2 Therefore, in step S200, it is necessary to first determine (V1F s -△HS1) / (V1-2D s Is the value of S1 greater than the set sealing performance coefficient e 2 , to measure the sealing performance of the pressure chamber.

[0098] In this embodiment, the solution of e=1.5 is exemplified. In other embodiments, the value of e can also be set according to actual needs.

[0099] S500: Determine the actual pressure P1 of the compressed gas to be filled into the pressure chamber based on m and P0.

[0100] Through step S500, the actual pressure P1 can be tightened based on P0 obtained in step S200, which can avoid the situation where the actual pressure of the actual gas does not meet the calculation range in S200 due to the ambient temperature, production cycle and slight leakage of gas in the pressure chamber during the pressing process, thereby improving the stability and reliability of the pressing effect during the operation.

[0101] Specifically, m(V1F s -2D s S1F s ) / (S1V1)≤P0≤(V1F s -△HS1F s ) / (S1V1) / m, so that the lower limit of the range of P1 is obtained by multiplying the lower limit value of P0 by m, and the upper limit of the range of P1 is obtained by dividing the upper limit value of P0 by m, so that the range of P1 is further tightened on the basis of the range of P0, ensuring the reliability of press-fitting.

[0102] S600: Install the stack pressing device on the press, fill the pressure chamber with compressed gas with a pressure value of P1, and package the fuel cell stack.

[0103] Optionally, step S600 may include the following steps:

[0104] When the fuel cell is packaged for the first time during the production cycle, the pressure of the compressed gas filled into the pressure chamber is P1 = P max , P max =m(V1F s -△HS1F s ) / (S1V1).

[0105] When the fuel cell is packaged for the nth time during the production cycle, the actual pressure P2 of the compressed gas in the pressure chamber is obtained, and the difference between P2 and P min The size of P min =m(V1F s -2D s S1F s ) / (S1V1), n ​​is an integer greater than 1.

[0106] If P2≥P min ; Then directly encapsulate, if P2<P min ; Then the compressed gas is added to the pressure chamber, and the pressure of the compressed gas P1=P max .

[0107] Because the sealing effect of the compressed gas in the pressure chamber is provided by the sealing ring, it will leak slowly over time. In the production process of subsequent batches, the first production of each batch is to choose to fill with compressed gas with the maximum pressure (the maximum value of P1). Then, in the production process after this batch, as long as it is confirmed that the pressure of the compressed gas in the pressure chamber is not less than the minimum value of P1, production can be carried out directly. When the pressure of the compressed gas in the pressure chamber is less than P1, the compressed gas with the maximum pressure (the maximum value of P1) is refilled, which can effectively improve production efficiency.

[0108] In addition, it should be noted that the press-fitting of fuel cell stacks is usually carried out in a constant temperature and humidity environment. The determination of P0 is also based on the premise of adapting to the actual temperature and humidity of the production site, so the influence of temperature and humidity can be ignored in P0.

[0109] The pressing method of the fuel cell stack pressing device provided in this embodiment can ensure the reliability of the actual pressure of the compressed gas to be filled into the pressure chamber through steps S100 to S600, thereby ensuring the reliable pressing quality of the fuel cell stack.

[0110] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A stack press-assembly device, characterized in that: include: A connecting seat, wherein the connecting seat is provided with a pressure chamber and an interface communicating with the pressure chamber, the interface being used to input compressed gas into the pressure chamber, the pressure chamber comprising a communicating chamber and a plurality of sub-chambers communicating with the communicating chamber; A plurality of floating pressure blocks are arranged in a one-to-one correspondence with the plurality of sub-chambers, one end of the floating pressure block is slidably located in the sub-chamber, and the other end of the floating pressure block extends out of the sub-chamber and is used to apply a compressive force to the fuel cell stack.

2. The battery stack press assembly device according to claim 1, characterized in that: The battery stack press-assembly device further includes a pressure gauge, which is used to detect the pressure of the gas in the pressure chamber.

3. The battery stack press assembly device according to claim 1, characterized in that: The battery stack pressing device also includes a plurality of limit brackets, each of which is detachably connected to the connecting seat, and the plurality of limit brackets are arranged in a one-to-one correspondence with the plurality of floating pressure blocks, and the limit brackets are provided with a plurality of avoidance holes, and the plurality of avoidance holes are all connected to the sub-chambers; the floating pressure block includes a pressure block body and a plurality of pressure heads, and the plurality of pressure heads are arranged at intervals in the pressure block body, and the pressure block body can be slidably located in the corresponding sub-chamber, and the plurality of pressure heads are passed through the plurality of avoidance holes in a one-to-one correspondence, and the pressure block body can abut against the limit bracket.

4. The battery stack press assembly device according to claim 3, characterized in that: The floating pressure block further comprises a first sealing ring sleeved on the pressure block body, and the first sealing ring is sealed and fitted with the pressure block body and the cavity wall of the sub-chamber respectively.

5. The battery stack press assembly device according to claim 1, characterized in that: The connecting seat includes a main seat body, a cover plate and a second sealing ring. The main seat body and the cover plate are detachably connected, and the main seat body and the cover plate enclose the pressure chamber. The second sealing ring is arranged between the main seat body and the cover plate, and the second sealing ring is sealed and fitted with the main seat body and the cover plate respectively.

6. The battery stack press assembly device according to claim 1, characterized in that: The stack press-assembly device further comprises a quick-connect connector installed at the interface, and the quick-connect connector is used to connect to an external gas source.

7. A method for pressing a battery stack press assembly device, characterized in that: The battery stack press-assembly device according to any one of claims 1 to 6 is implemented, and the press-assembly method of the battery stack press-assembly device includes: Obtain the design parameters of the fuel cell stack to be packaged and the stack pressing device, the design parameters of the fuel cell stack to be packaged and the stack pressing device include: the packaging force F of the fuel cell stack to be packaged s , the area S1 of the floating pressure block that bears the compressed gas pressure, the maximum sliding distance D of the floating pressure block s , the maximum difference in the design height of the fuel cell stack △H, and the maximum effective volume V1 of the pressure chamber; Determine the initial pressure P0 of the compressed gas to be filled into the pressure chamber based on the design parameters of the fuel cell stack to be packaged and the stack press assembly device; Obtain the current production cycle t and the current leakage mass flow Q of the pressure chamber of the stack press assembly device; Determine the correction factor m based on t and Q; Determine the actual pressure P1 of the compressed gas to be filled into the pressure chamber based on m and P0; The stack pressing device is installed on the press, and compressed gas with a pressure value of P1 is filled into the pressure chamber, and the fuel cell stack is packaged.

8. The press-assembly method of the battery stack press-assembly device according to claim 7, characterized in that: The initial pressure P0 of the compressed gas to be filled into the pressure chamber is determined based on the design parameters of the fuel cell stack to be packaged and the stack press assembly device, including: Judgment (V1F s -△HS1) / (V1-2D s S1) is greater than the square of the set sealing performance coefficient e; if so, the relationship between the design parameters of the fuel cell stack to be packaged and the stack press-fitting device and the initial pressure P0 of the compressed gas to be filled in the pressure chamber is: <h2 style=";text-align:left;direction:ltr">(V1F<h2 style=";text-align:left;direction:ltr"> s <h2 style=";text-align:left;direction:ltr"> -2D<h2 style=";text-align:left;direction:ltr"> s <h2 style=";text-align:left;direction:ltr"> S1F<h2 style=";text-align:left;direction:ltr"> s <h2 style=";text-align:left;direction:ltr"> ) / (S1V1)≤P0≤(V1F<h2 style=";text-align:left;direction:ltr"> s <h2 style=";text-align:left;direction:ltr"> -△HS1F<h2 style=";text-align:left;direction:ltr"> s <h2 style=";text-align:left;direction:ltr"> ) / (S1V1)。 9. The press-assembly method of the battery stack press-assembly device according to claim 8, characterized in that: The formula for determining the correction factor m based on T1 and Q is: m=1+(T0QtR) / (P0V1M)+a; Wherein, T0 is the preset ambient temperature, R is Avogadro's constant, M is the molar mass of the filled gas, and a is a constant.

10. The press-assembly method of the battery stack press-assembly device according to claim 9, characterized in that: Filling the pressure chamber with compressed gas having a pressure value of P1 and packaging the fuel cell stack includes: When the fuel cell is packaged for the first time during the production cycle, the pressure of the compressed gas filled into the pressure chamber is P1 = P max , P max =(V1F s -△HS1F s ) / (S1V1m); When the fuel cell is packaged for the nth time during the production cycle, the actual pressure P2 of the compressed gas in the pressure chamber is obtained, and the difference between P2 and P min The size of P min =m(V1F s -2D s S1F s ) / (S1V1), n ​​is an integer greater than 1; If P2≥P min ; Then directly encapsulate, if P2<P min ; Then the compressed gas is added to the pressure chamber, and the pressure of the compressed gas P1=P max .

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