A fuel cell stack leak detection device

Abstract

The present invention is a fuel cell stacking leak detection device, a fuel cell stacking leak detection device, mainly including a lifting mechanism, a positioning mechanism, a pressure mechanism, an airtightness detection mechanism, etc. The pressure mechanism includes the frame of the device, and other mechanisms are placed inside the mechanism. The above mechanisms cooperate with each other to assist in completing the stacking and airtightness detection process. The pressure mechanism of the present invention includes: a press base, a pressure sensor, a press outer frame, a pressure motor, a pressure guide column, a press column, a pressure rod, a press support, a pressure contact plate and a pressure sensor. The press base is on a horizontal ground, the press outer frame stands on the press base, the pressure motor is on the top of the press outer frame, controls the extension and contraction of the pressure rod, the end of the pressure rod is connected to the pressure connecting plate, and then the pressure is transmitted to the pressure contact plate through the pressure guide column. In order to monitor the size of the press pressure in real time, the pressure sensor and the press column are connected and placed on the press base platform and connected to the press support.

Description

Technical Field

[0001] The invention relates to a fuel cell stack assembly and quality detection technology, and belongs to the field of fuel cell production, in particular to a fuel cell stack assembly leak detection device. Background Art

[0002] The proton exchange membrane fuel cell (PEMFC) is composed of multiple stacked sub-electrodes, including anode and cathode bipolar plates, membrane electrodes, copper electrodes, mounting plates and other components. The assembly process is relatively long and time-consuming. After the stack is assembled, the anode channel, cathode channel and cooling channel need to be tested for air tightness to prevent gas from flowing between the channels and affecting product performance and safety. In the prior art, most fuel cells first complete the assembly and packaging of the stack and then perform air tightness testing on the stack. If the air tightness is detected to be unqualified, the stack will be dismantled for re-inspection, which is too inefficient. At the same time, the components of the stack may be damaged during the disassembly and reassembly process, increasing costs. In addition, the stack is large in size and heavy in weight, which is not easy to transfer. It is laborious to carry it between different equipment manually. At the same time, collisions and severe vibrations will also affect the performance of the stack.

[0003] The utility model patent with publication number CN201921606866.1 provides a servo rotary fuel cell stack assembly machine. During the stacking and leak detection process in the test, the positioning rod needs to be disassembled and assembled many times, and the air tightness test must be carried out after packaging. Because each part relies on its own gravity to contact and align with the positioning rod, the solution provided cannot be used to perform leak detection without removing the positioning rod, otherwise the press will interfere with the positioning rod. In addition, the repeated disassembly and assembly of the positioning rod will affect the stacking accuracy and cannot meet the actual production needs.

[0004] The utility model patent with publication number CN201922436019.1 provides a multi-purpose tooling for fuel cell stack assembly and leak detection. This tooling is only suitable for the stack screw packaging method and is not compatible with the current mainstream trend of strapping and side panel packaging. If strapping is added, the fixture cannot ensure the neat stacking of materials only through positioning holes and positioning columns, and there will be interference with the actual assembly with the press. There are no sealing elements between the fixture and the various inlets and outlets of the stack, and the air tightness during the test cannot be guaranteed. The three channels for air intake and exhaust on both sides share an air cavity, and it is impossible to perform air tightness detection on a single channel, which does not meet the actual use needs.

[0005] The above two methods are not suitable for mass production and require repeated disassembly and assembly of positioning fixtures, which is inconvenient in actual use and also affects the production rhythm.

[0006] In view of the above problems, the technical problem to be solved by the present invention is to provide a fuel cell stack leakage detection equipment to solve the problem of packaging fuel cells while ensuring that they are in a qualified airtight state; to solve the problem that fuel cell stacks are large in size and heavy in weight, making them difficult to take and place on the equipment; to solve the problem of uneven neatness of components such as fuel cell stack plates and membrane electrodes when stacking; to solve the problem of improving product consistency and production efficiency in mass production of fuel cell stacks. Summary of the invention

[0007] The present invention provides a fuel cell stacking leak detection device, which mainly includes a lifting mechanism, a positioning mechanism, a pressure mechanism, an airtightness detection mechanism, etc. The pressure mechanism includes a frame of the device, and other mechanisms are placed inside the mechanism. The above mechanisms cooperate with each other to assist in completing the stacking and airtightness detection process. The device is placed on a horizontal ground as a whole. Within the range of the manipulator lifting, the pressure mechanism of the present invention includes: a press base, a pressure sensor, a press outer frame, a pressure motor, a pressure guide column, a press column, a pressure rod, a press support, a pressure contact plate and a pressure sensor. The press base is on a horizontal ground, the press outer frame stands on the press base, the pressure motor is at the top of the press outer frame, controls the extension and contraction of the pressure rod, and the end of the pressure rod is connected to the pressure connecting plate, and then the pressure is transmitted to the pressure contact plate through the pressure guide column. The length of the pressure rod depends on the height of the stack. In order to monitor the size of the press pressure in real time, the pressure sensor and the press column are connected and placed on the press base platform and connected to the press support.

[0008] Furthermore, the positioning mechanism of the present invention includes: a positioning column, a positioning column guide rail, a positioning push rod, a positioning cylinder and a positioning platform; the positioning mechanism is placed as a whole on the press support, with two positioning columns on the back side and one positioning column on each of the left and right sides, a total of four positioning columns, all of which are installed in the positioning column guide rail, and the positioning columns on the left and right sides are connected to the cylinder push rod, and the positioning cylinder can control the positioning column to move forward and backward in the positioning column guide rail through the positioning push rod.

[0009] Furthermore, the lifting mechanism of the present invention comprises: a lifting cylinder, a lifting push rod, a cylinder support plate, and a lifting guide column. The lifting cylinder is placed in the press base, connected to the cylinder support plate through the lifting push rod, the lifting guide column fixed on the cylinder support plate is coaxial with the four guide holes on the bottom surface of the leak detection fixture, and a shock-absorbing pad is installed at the contact position between the lifting guide column and the leak detection fixture.

[0010] Furthermore, the airtightness detection mechanism of the present invention comprises: a leak detection fixture, a plug, a sealing ring and an external leak detection system. The mechanism is in a groove reserved by the positioning mechanism, and the leak detection fixture has a cathode air inlet, an anode air inlet and a cooling air inlet, and each air inlet is connected to its corresponding air inlet channel.

[0011] Furthermore, the present invention includes a manipulator when implementing fully automatic generation, which is placed on the side of the device without the positioning column, and maintains a suitable distance from the battery stack to allow the manipulator to complete the placement of various materials on the device and the removal of the battery stack. The manipulator can automatically change the tooling according to the type and function of the material.

[0012] Furthermore, in the present invention, the manipulator needs to lift the jig together when removing the battery stack from the equipment. The bottom of the jig has a countersunk hole corresponding to the position of the lifting rod and can be inserted to a certain depth, so that the battery stack is more stable when being lifted.

[0013] The present invention has two sets of jigs that can be used alternately, and the spare jigs are placed near the equipment, and the placement of the jigs can be completed manually or by a robot.

[0014] The assembly of the fuel cell stack first requires the use of a positioning mechanism to ensure that all components are aligned with each other, and then a pressure mechanism provides a constant pressure to the airtightness detection mechanism to complete the stack leak detection, and the stack is made to reach a predetermined height to complete the packaging and fixation, and finally the stack is lifted from the device to an operable position by a lifting mechanism, and then the stack is taken away by a robot. All of the above processes cooperate with each other without interfering with each other, and can realize the integration of functions such as stack installation, leak detection and transfer.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The invention can complete the two processes of fuel cell stack assembly and process testing on the same equipment at the same time, ensuring that the airtightness of the packaged stack is qualified, avoiding the increase in workload due to stack leakage and repair, and reducing the impact on the airtightness of the stack when moving between different workstations.

[0017] 2. The invention provides a semi-automatic method for completing the two processes of stacking and airtightness testing, thereby improving production efficiency and ensuring product consistency, and meeting the actual needs of stacking and leak detection in mass production of fuel cells.

[0018] 3. The invention is compatible with a variety of battery stack packaging methods, such as strap packaging, screw packaging and side panel packaging.

[0019] 4. This invention can be used for laboratory research and development and loading, as well as for automated batch production.

[0020] 5. The invention adds a positioning device to align the various materials in the stack during the stacking process;

[0021] 6. The invention can meet the needs of assembly and testing of battery stacks with different numbers of cells and specifications, such as metal plate battery stacks, graphite plate battery stacks, etc.;

[0022] 7. The invention can realize continuous operation. To ensure the rhythm, two sets of jigs can be used alternately. After the robot removes the previously packaged battery stack together with the jig, another set of jigs can be immediately placed to continue stacking production.

[0023] 8. The invention uses a robot to complete the transfer of the battery stack from the equipment, and can smoothly rotate the battery stack to an angle that assists subsequent processes, making it easier for subsequent processes to proceed.

[0024] 9. The robot in the invention can assist in the disassembly of the battery stack to avoid damage and mixing of key components such as membrane electrodes due to manual labor. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of the present invention for leak detection after fuel cell stacking;

[0026] Figure 2 This is a schematic diagram of the overall structure of the battery stack after the battery stack packaging is completed in the present invention;

[0027] Figure 3 It is a schematic diagram of the positioning mechanism structure of the present invention;

[0028] Figure 4 A leak detection jig of the present invention;

[0029] Figure 5 It is a cross-sectional schematic diagram of the leak detection fixture of the present invention;

[0030] Figure 6 It is a schematic diagram of the lifting mechanism structure of the present invention;

[0031] Figure 7 This is a structural diagram of the external leak detection system of the present invention.

[0032] 1. Press base; 2. Lifting mechanism; 3. Pressure sensor; 4. Unpackaged fuel cell stack;

[0033] 5. Leak detection fixture; 6. Pressure contact plate; 7. Positioning mechanism; 8. Pressure guide column; 9. Pressure connecting plate; 10. Pressure rod 11. Press frame; 12. Pressure motor; 13. Lifting push rod; 14. Lifting cylinder; 15. Positioning column; 16. Positioning column guide rail; 17. Fuel cell stack after packaging; 18. Lifting guide column; 19. Press support; 20. Positioning cylinder; 21. Positioning platform; 22. Positioning push rod; 23. Anode air inlet; 24. Cooling air inlet; 25. Cathode air inlet; 26. Cathode channel of the stack; 27. Cooling channel of the stack; 28. Binding groove; 29. ​​Anode channel of the stack; 30. Plug; 31. Sealing ring; 32. Cylinder support plate; 33. Press column. DETAILED DESCRIPTION

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] A fuel cell stack leak detection device provided by the present invention.

[0036] Embodiment 1: Full-automatic solution

[0037] Before stacking, the positioning cylinder push rod is in a tightened state, and the positioning column is in a direction away from the fuel cell stack. The manipulator sequentially stacks components such as the fuel cell stack end plate, bipolar plates, and membrane electrode assemblies on the leak detection tooling in a specified order, slowly descends along the positioning column. After the assembly of the last component is completed, the positioning cylinder controls the positioning push rod to push the left and right positioning rods to clamp each component of the fuel cell stack, aligning each component. The pressure motor is started, and the pressure rod extends to press the pressure contact plate against the fuel cell stack and apply a certain pressure. The airtightness detection mechanism is started, and the externally connected gas path is respectively connected to the anode air inlet, cathode air inlet, and cooling air inlet of the leak detection jig. When measuring the anode channel, solenoid valve A is opened, compressed air enters the fuel cell stack, and solenoid valve A is closed to stop the air intake after the gas pressure gauge at the intake end shows that the intake air pressure has reached. The pressure sensor monitors the pressure change amount, and the same steps are performed for the cathode and cooling channels. If any channel exceeds the qualified test standard, the airtightness of the fuel cell stack does not meet the standard, exhaust valves A / B / C are opened, the pressure motor is started in reverse, the pressure rod retracts, and after troubleshooting, the above actions are repeated. If the airtightness of all three channels is qualified, the fuel cell stack is encapsulated by the manipulator. The positioning cylinder is started to pull the positioning rod in a direction away from the fuel cell stack. The lifting cylinder is started to drive the lifting push rod to extend, driving the lifting guide post to pass through the four reserved holes on the press support. The shock pads at the top of the lifting guide post contact the four positioning holes at the back of the leak detection jig, smoothly ejecting the fuel cell stack to a height where the "C"-shaped fixture of the manipulator can extend in and out. After the manipulator clamps the fuel cell stack, it rotates 180 degrees to turn the bottom surface of the fuel cell stack upward and transfers it to the next station to install other components such as the adapter plate and interface.

[0038] Embodiment 2: Semi-automatic solution

[0039] This solution is applicable to small-batch production to handle various possible packaging methods, and the stack packaging is completed manually. Before stacking, the positioning cylinder push rod is in a tightened state, and the positioning post is away from the stack. The manipulator stacks components such as the stack end plate, bipolar plates (anode and cathode), and membrane electrode on the leak detection fixture in the specified order, and slowly drops along the positioning post. After the assembly of the last component is completed, the positioning cylinder controls the positioning push rod to push the left and right positioning rods to clamp each component of the stack, aligning each component. The pressure motor is started, and the pressure rod extends to press the pressure contact plate against the stack and apply a certain pressure. The airtightness detection mechanism is started, and the externally connected air circuit is connected to the anode air inlet, cathode air inlet, and cooling air inlet of the leak detection fixture respectively. When measuring the anode channel, solenoid valve A is opened, compressed air enters the stack, and solenoid valve A is closed to stop the air intake after the gas pressure gauge at the intake end shows that the intake air pressure has reached. The pressure sensor monitors the pressure change. The same steps are carried out for the cathode and cooling channels. If any channel fails to pass the qualified test, the airtightness of the stack does not meet the standard, and exhaust valves A / B / C are opened, and the pressure motor is started in reverse, and the pressure rod retracts. After troubleshooting, the above actions are repeated. If the airtightness of all three channels is qualified, the stack packaging is completed manually. The positioning cylinder is started to pull the positioning rod away from the stack. The lifting cylinder is started to drive the lifting push rod to extend, driving the lifting guide post to pass through the four reserved holes on the press support. The shock pads at the top of the lifting guide post contact the four positioning holes behind the leak detection fixture, and the stack is smoothly pushed out and raised to the height where the "C"-shaped fixture of the manipulator can extend in and out. After the manipulator clamps the stack, it rotates 180 degrees to turn the bottom of the stack upward and transfers it to the next station to install other components such as the adapter plate and interface.

[0040] Embodiment 2: Manual Solution

[0041] This solution is suitable for research and development. Considering the limitation of the site on the manipulator, the relevant processes are completed manually. Before loading, the positioning cylinder push rod is in a tightened state, and the positioning column is away from the stack. The tail plate, anode and cathode bipolar plates, membrane electrode and other parts are stacked on the leak detection fixture in the specified order, and slowly fall along the positioning column. After the last piece of parts is assembled, the positioning cylinder controls the positioning push rod to push the left and right positioning rods to tighten the various parts of the stack so that each piece of parts is aligned. The pressure motor is started, and the pressure rod is extended to press the pressure contact plate and the stack and apply a certain pressure. The air tightness detection mechanism is started, and the externally connected gas path is connected to the anode air inlet, cathode air inlet and cooling air inlet of the leak detection fixture respectively. When measuring the anode channel, the solenoid valve A is opened, and the compressed air enters the stack. The gas pressure gauge at the air intake end shows that the air pressure reaches the solenoid valve A, and the air intake is stopped. The air pressure sensor monitors the pressure change. The cathode and cooling channels follow the same steps. If any channel exceeds the qualified test, the gas tightness of the fuel cell stack does not meet the standard, the exhaust valve A / B / C opens, the pressure motor starts to reverse, the pressure rod is retracted, and the above actions are repeated after troubleshooting. If the gas tightness of the three channels is qualified, the fuel cell stack is packaged manually. The positioning cylinder is started to pull the positioning rod away from the fuel cell stack. The lifting cylinder is started, driving the lifting push rod to extend, driving the lifting guide column to pass through the four spaces reserved on the press support, and the shock-absorbing pad at the top of the lifting guide column contacts the four positioning holes on the back of the leak detection fixture to smoothly push the fuel cell stack out. The fuel cell stack is manually carried to the mobile cart for transportation.

[0042] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A fuel cell stack leak detection device, characterized in that: It includes a lifting mechanism, a positioning mechanism, a pressure mechanism, and an airtightness detection mechanism. The pressure mechanism includes the frame of the equipment. The lifting mechanism, the positioning mechanism, and the airtightness detection mechanism are separately placed inside the frame of the pressure mechanism. The lifting mechanism, the positioning mechanism, and the airtightness detection mechanism cooperate with each other to jointly assist in completing the battery stack assembly and airtightness detection process; The pressure mechanism comprises: a press base, a press outer frame, a pressure motor, a pressure guide column, a press column, a pressure rod, a press support, a pressure contact plate and a pressure sensor; The press base is on a horizontal ground, the press outer frame stands on the press base, the pressure motor is on the top of the press outer frame, controls the extension and retraction of the pressure rod, the end of the pressure rod is connected to the pressure connecting plate, and then the pressure is transmitted to the pressure contact plate through the pressure guide column, the pressure sensor is connected to the press column and placed on the press base platform and connected to the press support; The positioning mechanism comprises: a positioning column, a positioning column guide rail, a positioning push rod, a positioning cylinder and a positioning platform; The positioning mechanism is placed on the press support as a whole, with two positioning columns on the rear side, one positioning column on each of the left and right sides, a total of four positioning columns, all of which are installed in the positioning column guide rails, and the positioning columns on the left and right sides are connected to the positioning push rods. The positioning cylinder can control the positioning column to move forward and backward in the positioning column guide rail through the positioning push rod; The lifting mechanism comprises: a lifting cylinder, a lifting push rod, a cylinder support plate, and a lifting guide column; The lifting cylinder is placed in the press base and connected to the cylinder support plate through a lifting push rod. The lifting guide column fixed on the cylinder support plate is coaxial with the four guide holes on the bottom surface of the leak detection fixture. A shock-absorbing pad is installed at the contact position between the lifting guide column and the leak detection fixture. The air tightness detection mechanism includes: a leak detection fixture, a plug, a sealing ring and an external leak detection system; The airtightness detection mechanism is in a groove reserved by the positioning mechanism, and the leak detection fixture is provided with a cathode air inlet, an anode air inlet and a cooling air inlet, and each air inlet is connected to its corresponding air inlet channel.

2. An operating method of the fuel cell stack leak detection device according to claim 1, characterized in that: The following steps are involved: Before loading the stack, the positioning cylinder controls the positioning push rod to be in a tightened state, and the positioning column is away from the stack; The manipulator stacks the tail plate, anode and cathode bipolar plates, and membrane electrode components on the leak detection fixture in the specified order, and slowly drops them along the positioning columns. After the last component is assembled, the positioning cylinder controls the positioning push rod to push the left and right positioning columns to tighten the components of the stack and align each component. The pressure motor starts, the pressure rod extends to press the pressure contact plate and the battery stack and apply a certain pressure, the air tightness detection mechanism starts, and the externally connected air path is connected to the anode air inlet, cathode air inlet and cooling air inlet of the leak detection fixture respectively; When measuring the anode channel, the solenoid valve A is opened, and compressed air enters the fuel cell stack. After the gas pressure gauge at the intake end shows that the intake pressure reaches a certain level, the solenoid valve A is closed to stop the intake. The air pressure sensor monitors the pressure change. The detection steps of the cathode channel and the cooling channel are the same as those of the anode channel. If any channel passes the qualified test but the airtightness of the stack fails to meet the standard, the exhaust valves A / B / C will open, the pressure motor will start to reverse, and the pressure rod will retract. After troubleshooting, repeat the above actions; if the airtightness of all three channels is qualified, the stack encapsulation will be completed by the manipulator; the positioning cylinder will start, pulling the positioning rod away from the stack; the lifting cylinder will start, driving the lifting push rod to extend, driving the lifting guide column through the four reserved holes on the press support. The shock pads at the top of the lifting guide column will contact the four positioning holes behind the leak detection fixture, smoothly pushing the stack out and rising to the height where the "C"-shaped fixture of the manipulator can extend in and out. After the manipulator clamps the stack, it rotates 180 degrees to turn the bottom of the stack upwards and transfers it to the next station; Two sets of leak detection fixtures are used alternately. After the manipulator removes the previously encapsulated stack together with the leak detection fixture, another set of leak detection fixtures can be immediately placed to continue the stack loading production.

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