Full-automatic servo press-fitting stacking system of phosphoric acid fuel cell stack

Abstract

The invention relates to the field of fuel cells, discloses a full-automatic servo press-fitting and stacking system for a phosphoric acid fuel cell stack, and relates to the technical field of fuel cell manufacturing. The system comprises a double-section conveying belt, a phosphate spraying device, a weight detection device, a sub-stacking conveying belt, a visual positioning unit, a six-axis robot, a servo press and a control unit. The weight detection device obtains the weight difference of the electrode assembly before and after spraying through the weighing sensor so as to calculate the actual spraying load, and the control unit corrects the press fitting stop point coordinates of the servo press in real time according to the actual spraying load and counteracts tolerance accumulation generated by coating thickness fluctuation. The visual positioning unit recognizes the posture and gravity center deviation of the assembly and is used for dynamically adjusting the carrying acceleration of the robot and preventing the coating from moving. The system adjusts the speed of the sub-stacking conveying belts through the production takt synchronization model, and phase alignment of the spraying process and the stacking process is achieved. The full-process closed-loop control from material monitoring to precise press fitting is realized.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, specifically to a fully automated servo press-fit stacking system for phosphoric acid fuel cell stacks. Background Technology

[0002] A fuel cell stack is a core energy conversion unit composed of components such as bipolar plates, electrodes, and seals stacked alternately in a specific order. Current stack assembly processes typically employ semi-automated or manual stacking methods.

[0003] In existing assembly processes, the quality of phosphate coating on the electrode surface cannot be synchronized with the assembly end in real time, leading to dimensional tolerances between different component layers due to slight variations in coating thickness. These deviations accumulate during multi-layer stacking, making it difficult for the overall height of the finished fuel cell stack to meet design consistency requirements. Furthermore, during the transport of components with wet phosphate coatings from the conveyor belt to the stacking platform, the lack of dynamic kinetic parameter compensation makes the components highly susceptible to displacement or coating leveling deviation due to inertia from acceleration or deceleration. This compromises the component's positional accuracy on the stacking platform, directly impacting subsequent alignment quality.

[0004] Furthermore, traditional production lines often cannot effectively handle the rate differences between chemical spraying processes and mechanical stacking operations. Delays in quality inspection during the spraying process, or gaps in workstations caused by rejecting defective components, disrupt the cycle time of downstream stacking stations. This mismatch between processes leads to frequent idling or downtime of servo pressing equipment, limiting the overall operational efficiency and standardized production level of the production line. Therefore, developing integrated equipment capable of material monitoring, high-precision transfer, and adaptive pressing linkage has become a key requirement for improving fuel cell stack consistency and production quality. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a fully automated servo press-fit stacking system for phosphoric acid fuel cell stacks, which solves the problems of low efficiency, poor consistency, and inaccurate pressure control during the assembly of fuel cell stacks.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: a fully automated servo press-fit stacking system for phosphoric acid fuel cell stacks, comprising a dual-section conveyor belt 1, a phosphate spraying device 2, a weight detection device 3, a sub-stack conveyor belt 4, a vision positioning unit 5, a six-axis robot 6, a servo press 7, a control unit 8, a stacking platform 9, and a sub-stack platform 10.

[0007] The phosphate spraying device 2 is positioned above the dual-section conveyor belt 1 and includes a phosphate storage tank 21, a stirrer 22, a pump 23, a pipeline 24, and a nozzle 25. The stirrer 22 maintains a uniform slurry concentration, and the pump 23 delivers the slurry to the nozzle 25 for spraying the electrode assembly. The weight detection device 3 includes a weighing sensor A31 at the inlet end of the spraying station and a weighing sensor B32 at the outlet end, used to obtain the weight difference of the assembly before and after spraying and calculate the actual spraying load. The control unit 8 extracts the actual spraying load of each layer of the assembly and, combined with the theoretical design thickness of the assembly and the linear compensation factor, calculates the target bottom dead center displacement coordinate of the servo press 7 in real time. This transforms the micro-fluctuations in the chemical spraying amount into physical displacement corrections for mechanical pressing, eliminating dimensional tolerances caused by the accumulation of multiple coating thicknesses.

[0008] The visual positioning unit 5 identifies the center coordinates, deflection angle, and center of gravity deviation of the component through the processing module 52. The control unit 8 calculates the total mass of the component based on the actual spraying load and determines the maximum allowable acceleration of the six-axis robot 6 during the handling process based on the gripping force and friction coefficient of the end effector. In the translation segment of the path planning, by limiting the resultant acceleration, displacement or leveling shift of the wet phosphate coating on the electrode surface due to inertia is prevented, ensuring the pose accuracy and coating integrity of the component during high-speed transport.

[0009] The sub-stacking platform 10 is located to the side of the dual-segment conveyor belt 1, used to pre-assemble electrodes and partitions into sub-stacking units, which are then transported to the gripping station via the sub-stacking conveyor belt 4. The control unit 8 establishes a production cycle synchronization model and dynamically adjusts the variable frequency speed of the sub-stacking conveyor belt 4 based on the real-time process pass rate statistically obtained by the weight detection device 3. This scheduling logic uses the periodic frequency of the servo press 7 as a reference and utilizes the physical length of the conveyor belt as a buffer space to absorb the discrete delays caused by quality inspection or rejection of defective products in the spraying process, thus achieving time phase alignment between the chemical spraying process and the mechanical stacking process.

[0010] The servo press 7 is mounted above the stacking platform 9 and integrates a pressure sensor and a displacement encoder. During the pressing process, the servo press 7 performs constant pressure pressing and monitors the numerical changes through the displacement encoder during the pressure holding time. If the displacement deviation exceeds the tolerance range, the control unit 8 feeds back the deviation to the starting point of the next pressing cycle for error correction, thereby realizing dynamic closed-loop control across cycles and ensuring the consistency of the overall height and the uniform distribution of internal contact pressure after the fuel cell stack is formed.

[0011] This invention provides a fully automated servo-controlled press-fit stacking system for phosphoric acid fuel cell stacks. It offers the following advantages: 1. This invention uses a weighing sensor to acquire the actual phosphate coating load of each electrode layer in real time. The control unit converts this mass load data into a thickness deviation value at the micrometer level and dynamically corrects the pressing stop displacement coordinates of the servo press. This closed-loop control method based on actual material measurement data eliminates the tolerance accumulation caused by the thickness fluctuation of multiple coating layers, ensuring the consistency of the total height of the formed fuel cell stack.

[0012] 2. The control unit of this invention combines the centroid deviation fed back by the visual positioning unit with the total mass of the electrode assembly to calculate the maximum allowable acceleration of the six-axis robot in real time, and constrains the resultant acceleration of the translation segment in the path planning. This mechanism effectively solves the displacement or leveling offset problem caused by the transport inertia of the wetted phosphate coating, ensuring the positioning accuracy of the component on the stacking platform.

[0013] 3. This invention establishes a production cycle synchronization model, dynamically adjusting the variable frequency speed of the sub-stacking conveyor belt based on the real-time process pass rate, and utilizing the physical length of the conveyor belt to achieve material buffering and phase alignment. This solution absorbs the discrete delays caused by quality inspection or rejection of defective products in the spraying process, maintains the continuous operation of the servo press, and avoids equipment idling or shutdown due to uneven material supply. Attached Figure Description

[0014] Figure 1 This is a structural diagram of the present invention.

[0015] Among them, 1: dual-section conveyor belt; 2: phosphate spraying device; 3: weight detection device; 4: sub-stacking conveyor belt; 5: vision positioning unit; 6: six-axis robot; 7: servo press; 8: control unit; 9: stacking platform; 10: sub-stacking platform. Detailed Implementation

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Example: Please see the appendix Figure 1 This invention provides a fully automated servo press-fit stacking system for phosphoric acid fuel cell stacks, the specific structure and connection relationships of which are described below: The fully automated servo press-fit stacking system for phosphoric acid fuel cell stacks includes a dual-section conveyor belt 1, a phosphate spraying device 2, a weight detection device 3, a sub-stack conveyor belt 4, a vision positioning unit 5, a six-axis robot 6, a servo press 7, a control unit 8, and a stacking platform 9.

[0018] The dual-section conveyor belt 1 is horizontally mounted on the system base and is used to sequentially transport the electrode assemblies and separator assemblies to be processed from the loading area to the subsequent spraying and inspection stations. The segmented structure of the dual-section conveyor belt 1 allows for independent speed adjustment of different components during transport.

[0019] The phosphate spraying device 2 is positioned above the dual-section conveyor belt 1 and includes a phosphate storage tank 21, a stirrer 22, a pump 23, pipes 24, nozzles 25, a spraying platform 26, and a gas collection hood 27. The stirrer 22 is located inside the phosphate storage tank 21 to maintain uniform coating. The pump 23 transports the phosphate slurry from the storage tank to the nozzles 25 via pipes 24. The nozzles 25 are positioned corresponding to the spraying platform 26 and are used to perform spraying operations on the substrate coating surface and the base surface of the electrode assembly.

[0020] Weight detection device 3 is installed before and after the spraying station of the dual-section conveyor belt 1. Specifically, weight detection device 3 includes a weighing sensor A31 located at the inlet end of the spraying station and a weighing sensor B32 located at the outlet end of the spraying station. Weighing sensor A31 is used to obtain the initial weight of the component before spraying, and weighing sensor B32 is used to obtain the real-time weight of the component after spraying, and transmits the data to control unit 8.

[0021] Sub-stacking conveyor 4 is positioned on one side of the main transport line and is used to transport pre-assembled sub-stacking components, individual seals, or bipolar plates. The discharge end of sub-stacking conveyor 4 points towards the gripping area of ​​the six-axis robot 6.

[0022] The visual positioning unit 5 is mounted above the grasping position and includes a CCD camera 51 and a processing module 52. The CCD camera 51 captures images of each component as it reaches the predetermined position. The processing module 52 identifies the type, spatial coordinates, and deflection angle of the component using an algorithm and sends the positioning data to the control unit 8.

[0023] The six-axis robot 6 is located between the sub-stacking conveyor belt 4 and the stacking platform 9. According to the coordinate instructions issued by the control unit 8, the six-axis robot 6 picks up the corresponding component from the conveyor belt and transports it directly above the stacking platform 9.

[0024] The servo press 7 is mounted on the vertical axis of the stacking platform 9. Its actuator is driven by the control unit 8 and performs surface pressure operation on the components on the stacking platform 9 according to the set pressure curve.

[0025] The control unit 8 is electrically connected to the dual-section conveyor belt 1, the phosphate spraying device 2, the weight detection device 3, the sub-stack conveyor belt 4, the vision positioning unit 5, the six-axis robot 6, and the servo press 7. The control unit 8 integrates a logic scheduling program, which processes the mass load data fed back by the weight detection device 3 and controls the pressing stop displacement of the servo press 7 in real time.

[0026] The stacking platform 9 serves as the bearing reference for the overall assembly of the fuel cell stack. It is located in the central working area of ​​the system and is used to receive the various layers of components dropped by the six-axis robot 6 and to work with the servo press 7 to complete the pressing.

[0027] The overall workflow of the system is as follows: the dual-section conveyor belt 1 delivers the components to the phosphate spraying device 2, and the weight detection device 3 monitors the weight difference before and after spraying in real time; the sub-stacked conveyor belt 4 delivers the pre-assembled sub-components to the gripping area; the control unit 8, combined with the pose coordinates fed back by the vision positioning unit 5, drives the six-axis robot 6 to perform component handling; finally, the servo press 7 performs stroke compensation pressing based on the cumulative mass load value obtained by the aforementioned weight detection device 3.

[0028] This invention provides a fully automated servo press-fit stacking method for fuel cell stacks, applied to the aforementioned fully automated servo press-fit stacking system for phosphoric acid fuel cell stacks. The method comprises the following steps: The dual-section conveyor belt 1 receives the electrode assembly to be processed. The electrode assembly obtains its initial weight data before spraying by the weighing sensor A31 of the weight detection device 3. The dual-section conveyor belt 1 transfers the electrode assembly to the spraying platform 26 of the phosphate spraying device 2.

[0029] The phosphate spraying device 2 sprays slurry onto the designated surface of the electrode assembly through the nozzle 25. After spraying, the electrode assembly is fed into the weighing sensor B32 by the dual-segment conveyor belt 1. The weighing sensor B32 acquires the real-time weight data of the electrode assembly after spraying and sends it to the control unit 8.

[0030] The control unit 8 calculates the current coating quality change value of the electrode assembly based on the initial weight data and the real-time weight data. The control unit 8 then determines whether the coating quality change value is within a preset threshold range.

[0031] The sub-stacking conveyor 4 synchronously transports pre-assembled sub-stacking components, seals, or bipolar plates to the gripping station. The operating speed of the sub-stacking conveyor 4 is regulated by the control unit 8 to ensure that the arrival frequency of the sub-stacking components matches the processing frequency of the electrode components.

[0032] The visual positioning unit 5 acquires image information of each component at the gripping station through the CCD camera 51. The processing module 52 calculates the center coordinates and deflection angle of the component based on the image information and feeds the results back to the control unit 8.

[0033] The control unit 8 combines component quality information and visual positioning data to generate motion control parameters for the six-axis robot 6. The six-axis robot 6 grasps the components according to the control parameters and places them onto the stacking platform 9 along a preset path.

[0034] Each time the six-axis robot 6 delivers a layer of components, the servo press 7 performs one pressing action. When the number of stacked layers reaches the preset number of pressing cycles, the servo press 7 enters the pressure holding state.

[0035] During the pressing process, the control unit 8 extracts the coating quality change values ​​of each stacked layer in real time. The control unit 8 calculates the stroke compensation amount based on the cumulative data of coating quality change values, and corrects the pressing stop coordinates of the servo press 7 accordingly, until the pressing operation of the entire electric stack is completed.

[0036] The phosphate spraying device 2 includes a phosphate storage tank 21, a stirrer 22, a pump 23, a pipeline 24, a nozzle 25, a spraying platform 26, and a gas collection hood 27.

[0037] A phosphate storage tank 21 is fixedly mounted on the system support and is used to store the phosphate slurry to be sprayed. An agitator 22 is coaxially mounted inside the phosphate storage tank 21, with its drive end extending to the outside of the tank and connected to a stirring motor. The agitator 22 mechanically stirs the slurry inside the phosphate storage tank 21 through rotational motion to maintain the uniformity of the slurry concentration and prevent solid particles from settling.

[0038] Pump 23 is installed at the outlet of the bottom of phosphate storage tank 21, and the input end of pump 23 is connected to phosphate storage tank 21 through pipe 24. The output end of pump 23 is connected to nozzle 25 through another pipe 24. Pump 23 is driven by control unit 8 to deliver phosphate slurry at a predetermined pressure to nozzle 25 in a metered manner.

[0039] The nozzle 25 is suspended above the spraying platform 26 by a bracket. The nozzle of the nozzle 25 faces the working area of ​​the spraying platform 26 and is used to atomize the received slurry and spray it onto the surface of the electrode assembly.

[0040] The spraying platform 26 is set on the conveying path of the dual-section conveyor belt 1. The surface of the spraying platform 26 is equipped with a positioning mechanism for fixing the electrode assembly to be sprayed. The bottom of the spraying platform 26 is equipped with a recycling tank for collecting excess slurry generated during the spraying process.

[0041] A fume hood 27 is installed in the external space between the nozzle 25 and the spraying platform 26. The top of the fume hood 27 has an exhaust port connected to an external ventilation system. The fume hood 27 is used to collect the mist and volatile gases generated during the spraying process and prevent the exhaust gases from spreading to the external environment.

[0042] The phosphate spraying device 2 adjusts the rotation speed of the pump 23 and the opening duration of the nozzle 25 through the control unit 8, thereby precisely controlling the amount of phosphate load applied to the electrode assembly matrix coating surface and the substrate surface.

[0043] The weight detection device 3 includes a weighing sensor A31 installed at the inlet of the spraying station and a weighing sensor B32 installed at the outlet of the spraying station. Weighing sensors A31 and B32 are electrically connected to the control unit 8. A dual-section conveyor belt 1 transports the electrode assembly to be sprayed to the location of weighing sensor A31. Weighing sensor A31 performs static or dynamic weighing on the electrode assembly to obtain its initial weight data before the spraying process. The control unit 8 receives and stores this initial weight data. And establish an index relationship between this data and the corresponding electrode component number.

[0044] The electrode assembly is transferred by a dual-section conveyor belt 1 to the phosphate spraying device 2 for spraying. After spraying, the electrode assembly continues to be transported by the dual-section conveyor belt 1 to the location of the weighing sensor B32. The weighing sensor B32 weighs the electrode assembly with the phosphate coating and obtains the real-time weight data after spraying. .

[0045] Control unit 8 retrieves the initial weight data corresponding to the number in real time. With real-time weight data The control unit 8 obtains the actual coating load of the electrode assembly through differential calculation. The spray load The data will be synchronously sent to the central control program that executes the servo press-fit logic.

[0046] The sampling frequencies of load cells A31 and B32 are adjusted in real time by control unit 8 according to the transmission speed of the dual-segment conveyor belt 1. This coordinated arrangement of dual load cells enables online monitoring of the coating quality of each electrode assembly. Control unit 8 adjusts the sampling frequency based on the actual coating load. Establish component quality profiles. When actual coating load is detected... When the load deviates from the preset standard load range, the control unit 8 issues a stop command to the dual-section conveyor belt 1 or a rejection command to the sorting mechanism to ensure that the components entering the stacking platform 9 meet the process specifications.

[0047] The control unit 8 receives weighing data from the weight detection device 3 in real time. When the number is... When the electrode assembly passes through the weighing sensor A31, the control unit 8 records and stores the initial weight data. When the number is When the electrode assembly completes the coating process and passes through the weighing sensor B32, the control unit 8 records the real-time weight data. The control unit 8 performs a subtraction operation through a preset calculation module to determine the actual coating load of the electrode assembly. The calculation formula is: .

[0048] Calculated actual spraying load The mass attribute parameters of the electrode assembly are stored in the database of the control unit 8. The control unit 8 calculates the actual spraying load. Compare with the preset standard load range. The standard load range is defined by an upper threshold. and lower threshold composition.

[0049] If the conditions are met If the actual spraying load is within acceptable limits, then control unit 8 determines that the coating quality of the electrode assembly is qualified. If the load exceeds the standard load range, the control unit 8 determines that the component is defective. For defective components, the control unit 8 sends a stop signal to the dual-section conveyor belt 1 or sends a rejection command to the subsequent sorting mechanism to prevent the defective component from entering the stacking platform 9.

[0050] Determining the acceptable actual spraying load The data is transmitted to the press-fit control module of the control unit 8. This data will serve as the basis for the subsequent stroke compensation performed by the servo press 7 to offset the cumulative height error of the fuel cell stack caused by minor fluctuations in the coating thickness.

[0051] Control unit 8 measures the actual spraying load of multiple consecutive electrode assemblies. Statistical analysis was performed to monitor the operating status of the phosphate spraying device 2 in real time. If If a trend of deviation is observed, the control unit 8 will automatically adjust the flow output parameters of the pump 23.

[0052] The visual positioning unit 5 includes a CCD camera 51 and a processing module 52. The CCD camera 51 is mounted above the confluence of the dual-section conveyor belt 1 and the sub-stacked conveyor belt 4, with its lens axis perpendicular to the horizontal conveying surface of the conveyor belt. The CCD camera 51 is used to perform real-time image capture of the electrode assembly, partition assembly, and sub-stacked assembly as they reach the gripping position.

[0053] The processing module 52 is electrically connected to the CCD camera 51 and is used to receive and parse image data. The processing module 52 extracts the geometric contour features of the component using a preset image recognition algorithm to identify the specific type of the component. Based on the extracted features, the processing module 52 calculates the position coordinates of the component's center in a two-dimensional coordinate system and its deflection angle relative to a preset reference position. .

[0054] Processing module 52 will identify the coordinate data and deflection angle. The data is transmitted to the control unit 8 in real time. The control unit 8 then corrects the target pose of the end effector of the six-axis robot 6 based on this positioning data. The vision perception module provides spatial reference for the six-axis robot 6 to perform grasping actions by accurately extracting the component poses.

[0055] When the visual positioning unit 5 performs the perception task, the processing module 52 also extracts the centroid distribution features of the component. For the electrode assembly after phosphate spraying, the processing module 52 identifies the distribution state of the sprayed liquid film and combines it with the aforementioned deflection angle. The center of gravity deviation of the components is calculated. This deviation is used as one of the input parameters for the control unit 8 to adjust the motion acceleration of the six-axis robot 6.

[0056] The sampling period of the visual perception module is synchronized with the feeding stepping frequency of the dual-segment conveyor belt 1 and the sub-stacking conveyor belt 4. Whenever a component enters the field of view of the CCD camera 51, the processing module 52 triggers a recognition task to ensure that each component to be stacked has independent pose index data before being grasped.

[0057] The control unit 8 receives component pose data transmitted by the visual positioning unit 5 processing module 52. This pose data includes the component's center coordinates and deflection angle. And the center of gravity deviation determined by the phosphate coating distribution. Simultaneously, the control unit 8 obtains the actual spraying load of the component from the weight detection device 3. .

[0058] Control unit 8 based on actual spraying load The total mass of the computing components The control unit 8 combines the pre-set gripping force of the six-axis robot 6's end effector. and the static friction coefficient between the coating surface and the actuator Calculate the maximum allowable acceleration of the six-axis robot during the handling process. .

[0059] Maximum permissible acceleration The calculation formula is: .in, This is the acceleration due to gravity.

[0060] Based on the calculation results, the control unit 8 sets the upper limit of the acceleration slope of the six-axis robot 6's motion trajectory to prevent the components from displacing relative to the end effector due to inertia during acceleration or deceleration.

[0061] The control unit 8 compensates for the offset of the gripping center of the six-axis robot 6 based on the center of gravity deviation fed back by the vision positioning unit 5. The control unit 8 drives the end effector of the six-axis robot 6 to perform the gripping action in alignment with the corrected center coordinates, thereby counteracting the torque imbalance caused by the uneven distribution of phosphate slurry.

[0062] During the process of the six-axis robot 6 transferring the component from the gripper to the stacking platform 9, the control unit 8 monitors the motion commands of the six-axis robot 6 in real time. If the command acceleration exceeds... The control unit 8 automatically smooths the motion curve to ensure that the component maintains spatial orientation stability throughout the transportation process.

[0063] The dynamic grasping compensation method transforms the physical state data of visual recognition into the robot's dynamic constraint parameters, enabling precise displacement control of the components with wet coatings and ensuring precise alignment on the subsequent stacking platform 9.

[0064] The control unit 8 sets the starting point of the path based on the component center coordinates determined by the visual positioning unit 5. The control unit 8 sets the ending point of the path based on the top height of the currently stacked components on the stacking platform 9. The control unit 8 constructs a three-dimensional spatial motion trajectory between the starting point and the ending point, which includes a lifting segment, a translation segment, and a descent segment.

[0065] In the lifting section, control unit 8 drives the six-axis robot 6 to move upwards along a direction perpendicular to the plane of the dual-segment conveyor belt 1 or the sub-stacked conveyor belt 4. The acceleration of the lifting section is limited by the maximum permissible acceleration calculated above. Control unit 8 ensures that the gripping force provided by the end effector is maintained the instant the component leaves the conveyor belt surface. It can overcome the gravity of components and the adhesion of coatings without causing relative slippage.

[0066] During the translation phase, control unit 8 controls the six-axis robot 6 to perform compound axis linkage motion in horizontal space. Control unit 8 extracts the spatial coordinates of obstacles on the path in real time and calculates the resultant acceleration in the tangential direction of the trajectory. This resultant acceleration is always maintained at the maximum permissible acceleration. Within the specified range. By limiting the horizontal centripetal acceleration and tangential acceleration, the phosphate coating on the component surface is prevented from leveling off towards the component edge due to inertia.

[0067] During the descent phase, control unit 8 guides the six-axis robot 6 to descend vertically to the placement position on the stacking platform 9. Control unit 8 combines the deflection angle feedback from vision positioning unit 5. Correct the rotation phase of the end effector of the six-axis robot 6. Before the component touches the stacking platform 9 or the top of the already stacked components, the control unit 8 instructs the six-axis robot 6 to perform a deceleration buffer action, reducing the descent speed to a preset contact threshold.

[0068] During path planning, control unit 8 continuously monitors the torque feedback of each joint of the six-axis robot 6. If abnormal fluctuations in dynamic parameters occur during the path, control unit 8 recalculates the smoothing curve in real time until the component is stably placed at the predetermined center position on the stacking platform 9. This path planning method, by deeply coupling kinematic trajectory with dynamic constraints, ensures the pose accuracy and coating integrity of the component during high-speed transport.

[0069] The invention also includes a sub-stacking platform 10 disposed on the side of the dual-segment conveyor belt 1. The sub-stacking platform 10 includes an assembly actuator for performing pre-assembly operations of electrode assemblies and separator assemblies to form a sub-stacking unit comprising an electrode-separator-electrode structure.

[0070] One end of the sub-stacking conveyor belt 4 is connected to the discharge port of the sub-stacking platform 10, and the other end extends to the gripping station of the six-axis robot 6. The sub-stacking conveyor belt 4 is driven by the control unit 8 and is responsible for sequentially conveying the pre-assembled sub-stacking units, individual seals or bipolar plates to the confluence point.

[0071] The control unit 8 uses the actual spraying load fed back by the weight detection device 3. The data stream is used to monitor the process output status of the phosphate spraying unit 2 in real time. When the weight detection device 3 determines that a certain electrode component is defective and performs a rejection action, the control unit 8 simultaneously extracts the station vacancy signal caused by the process loss.

[0072] Control unit 8 establishes a production cycle synchronization model. This model is based on the pressing cycle frequency of servo press 7. Based on this, the variable frequency speed of the sub-stacking conveyor belt 4 is adjusted. To eliminate rhythm deviations caused by fluctuations in the spraying process. Variable frequency speed. The calculation reference formula is as follows: In this formula, The characteristic distribution spacing of the components to be grabbed on the sub-stacked conveyor belt 4. The cycle frequency of the servo press 7 The real-time process pass rate is calculated by the weight detection device 3.

[0073] Control unit 8 adjusts the frequency converter speed in real time. This ensures that when a qualified electrode assembly arrives at the gripping station via the dual-segment conveyor belt 1, the corresponding sub-stack unit arrives at the predetermined gripping position simultaneously.

[0074] Control unit 8 utilizes the buffer space formed by the physical length of the sub-stacking conveyor belt 4 to absorb the discrete delays caused by slurry leveling or quality inspection in the phosphate spraying process. When the output speed of the phosphate spraying unit 2 lags due to process parameter adjustments, control unit 8 reduces the conveying rate of the sub-stacking conveyor belt 4. Once the phosphate spraying unit 2 returns to its standard rate, control unit 8 increases the operating frequency of the sub-stacking conveyor belt 4 according to the real-time layer requirements on the stacking platform 9 to compensate for material phase.

[0075] This scheduling scheme achieves linear alignment of the chemical spraying process and the mechanical stacking process in the time dimension. Through this cycle synchronization logic, the control unit 8 maintains the continuous operation of the six-axis robot 6 at the gripping station, avoiding the empty pressure or standby phenomenon caused by the servo press 7 due to inconsistent feeding rhythm.

[0076] The servo press 7 is mounted directly above the stacking platform 9, and a servo motor drives a lead screw mechanism to move the press head in a vertical reciprocating motion. The servo press 7 integrates a pressure sensor and a displacement encoder to acquire real-time pressing force data and the position coordinates of the press head. The control unit 8 performs closed-loop control of the servo press 7's actions using a preset adaptive compensation algorithm. This closed-loop pressing strategy specifically includes the following steps: S501, the control unit 8 obtains the layer number information of the component to be pressed onto the stacking platform 9. After the component is placed onto the stacking platform 9, the control unit 8 retrieves the actual spraying load corresponding to the component from the storage module. .

[0077] S502, Control Unit 8 performs stroke compensation calculation. Control Unit 8 calculates the stroke compensation amount based on the actual spraying load. The thickness deviation of a single layer due to fluctuations in the phosphate coating thickness is calculated. The calculation formula is as follows: In this formula, The target bottom dead center displacement coordinates of the servo press 7; This represents the current total number of stacked layers. For the first The theoretical design thickness of the layer component in the uncoated state, which is a preset known constant; It is a linear compensation factor for the evolution of spraying load and thickness, used to map the measured weight change value to the compensation amount of vertical height; For the first The actual spraying load of the layer component is measured by the weight detection device 3.

[0078] S503, Control Unit 8, based on the calculations... The motion trajectory control parameters of the servo press 7 are corrected. During the pressing action, the displacement encoder of the servo press 7 monitors the current position of the press head in real time. When the press head reaches the position corrected by the compensation algorithm... When the coordinates are in motion, the control unit 8 instructs the servo motor to stop feeding or switch to a pressure-holding state.

[0079] S504, Perform periodic pressing determination. Control unit 8 determines the periodic pressing cycle number based on the preset pressing cycle number. Counting is performed whenever the number of component layers on stacking platform 9 reaches a certain threshold. When the pressure is an integer multiple of the set value, the control unit 8 drives the servo press 7 to perform a constant pressure pressing operation. During the constant pressure pressing stage, the servo press 7 operates at a preset rated pressure. It acts on the component surface and maintains a preset holding time. .

[0080] S505 performs dual closed-loop verification of pressure and displacement. During the pressure holding time... Inside, control unit 8 continuously extracts the numerical changes from the displacement encoder. If at rated pressure... Below, the actual displacement of the pressure head is different from the calculated displacement. If the deviation exceeds the preset tolerance range, the control unit 8 records the deviation and feeds it back to the starting point of the next pressing cycle, thereby achieving cross-cycle error correction.

[0081] For the motor drive control and displacement encoder signal feedback of the servo press 7, those skilled in the art can select pulse control or bus control mode according to the actual accuracy requirements. The specific circuit connection and communication protocol are well known in the art and will not be described in detail here.

[0082] Through the above steps, the control unit 8 converts the chemical component load data acquired by the front-end weight detection device 3 into physical displacement constraints for the end-effector servo press 7. This dynamic compensation mechanism based on real-time material data eliminates dimensional tolerances caused by the accumulation of multi-layer coating thickness during the assembly process of the fuel cell stack, ensuring the consistency of the overall height and the uniform distribution of internal contact pressure after the stack is formed.

[0083] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A fully automated servo-controlled press-fit stacking system for phosphoric acid fuel cell stacks, characterized in that, The system includes a dual-section conveyor belt (1), a phosphate spraying device (2), a weight detection device (3), a sub-stacking conveyor belt (4), a vision positioning unit (5), a six-axis robot (6), a servo press (7), a control unit (8), a stacking platform (9), and a sub-stacking platform (10). The dual-section conveyor belt (1) is used to transport the electrode assembly and the partition assembly to be processed to the spraying station. The phosphate spraying device (2) is arranged above the dual-section conveyor belt (1) and is used to spray the electrode assembly. The weight detection device (3) includes a weighing sensor A (31) located at the inlet end of the spraying station and a weighing sensor A (31) located at the outlet end of the spraying station. The weight sensor B (32) is used to acquire the initial weight data before the component is sprayed and the real-time weight data after the component is sprayed. The visual positioning unit (5) is used to capture the component image information and extract the spatial coordinates, deflection angle and center of gravity deviation. The control unit (8) calculates the actual spraying load based on the initial weight data and the real-time weight data, and generates the motion control parameters of the six-axis robot (6) based on the center of gravity deviation. The servo press (7) is set above the stacking platform (9). The control unit (8) calculates the stroke compensation based on the accumulated actual spraying load and corrects the pressing stop coordinates of the servo press (7) accordingly.

2. The fully automated servo press-fit stacking system for phosphoric acid fuel cell stacks according to claim 1, characterized in that, The phosphate spraying device (2) includes a phosphate storage tank (21), a stirrer (22), a pump (23), a pipe (24), a nozzle (25), a spraying platform (26), and a gas collection hood (27); the stirrer (22) is coaxially installed inside the phosphate storage tank (21), and the control unit (8) controls the actual spraying load applied to the electrode assembly by adjusting the speed of the pump (23).

3. The fully automated servo press-fit stacking system for phosphoric acid fuel cell stacks according to claim 1, characterized in that, The sub-stacking platform (10) is located on the side of the dual-segment conveyor belt (1) and is used to assemble the electrode assembly and the partition assembly into a sub-stacking unit; the sub-stacking conveyor belt (4) connects the sub-stacking platform (10) to the gripping station of the six-axis robot (6).

4. The fully automated servo press-fit stacking system for phosphoric acid fuel cell stacks according to claim 3, characterized in that, The control unit (8) integrates a production cycle synchronization model. It adjusts the frequency conversion speed of the sub-stacking conveyor belt (4) in real time based on the real-time process pass rate statistically obtained by the weight detection device (3) so that the arrival frequency of the sub-stacking unit is in phase with the processing frequency of the electrode assembly.

5. The fully automated servo press-fit stacking system for phosphoric acid fuel cell stacks according to claim 4, characterized in that, The control unit (8) dynamically sets the variable frequency speed of the sub-stacked conveyor belt (4) based on the characteristic distribution spacing of the components to be grasped on the sub-stacked conveyor belt (4), the periodic frequency of the servo press (7), and the product and ratio of the real-time process qualification rate.

6. The fully automated servo press-fit stacking system for phosphoric acid fuel cell stacks according to claim 1, characterized in that, The control unit (8) calculates the total mass of the component based on the actual spraying load, and calculates the maximum allowable acceleration of the six-axis robot (6) during the handling process by combining the gripping force and friction coefficient of the end effector of the six-axis robot (6), and sets the upper limit of the acceleration slope of the motion trajectory.

7. The fully automated servo press-fit stacking system for phosphoric acid fuel cell stacks according to claim 1, characterized in that, The motion path of the six-axis robot (6) includes a lifting segment, a translation segment, and a descent segment; in the translation segment, the control unit (8) limits the resultant acceleration in the tangential direction of the trajectory to a preset range to prevent the phosphate coating on the surface of the electrode assembly from leveling off.

8. The fully automated servo press-fit stacking system for phosphoric acid fuel cell stacks according to claim 1, characterized in that, The control unit (8) executes an adaptive compensation algorithm to determine the target bottom dead center displacement coordinates of the press-fit stop point coordinates based on the current cumulative stacked total number of layers, the theoretical design thickness of each layer component, the actual spraying load, and the cumulative result of the preset linear compensation factor.

9. The fully automated servo press-fit stacking system for phosphoric acid fuel cell stacks according to claim 1, characterized in that, The servo press (7) is integrated with a displacement encoder; whenever the number of stacked layers reaches the preset number of pressing cycles, the control unit (8) controls the servo press (7) to perform constant pressure pressing and monitors the value change through the displacement encoder during the pressure holding time; if the displacement deviation exceeds the tolerance range, the displacement deviation is fed back to the next pressing cycle for error correction.

10. The fully automated servo press-fit stacking system for phosphoric acid fuel cell stacks according to any one of claims 1 to 9, characterized in that, The control unit (8) determines the qualification of the component based on the comparison result between the actual spraying load and the preset standard load range; if it exceeds the preset standard load range, it sends a rejection instruction to the sorting mechanism to prevent unqualified components from entering the stacking platform (9).

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