A technical centre for testing automated assembly techniques for polymer electrolyte membrane (PEMFC) fuel cell stacks and individual cells was built up within the framework of the “Fuel cell test field extension” project (BZ-Testfelderweiterung), which is funded by the German Federal Ministry for Economic Affairs and Energy. The focus of the facilities procured for the technical centre is on the media-impermeable joining of individual cells from large-format graphitic bipolar plates, as well as stacking fuel cell stacks. The production unit is installed in an air-conditioned room.
The centrepiece of the plant is a multi-axis robot station which is used to experiment with gripping and positioning brittle and pliable components and transferring the components between processing stations and stacking cells. Automation also includes a station for the application of seals by means of robotic dispensers as well as a station to test the tightness of manufactured components. An assembly press, an annealing oven and a station for the optical 3D-measurement of the channel geometries of the bipolar plates are also available.
The correct positional arrangement of the individual components is ensured by means of an optical image processing system. In addition, the application of the seals is monitored by inline process monitoring using a laser scanning system. The existing equipment in the technical centre allows for the investigation of various working steps such as the suitability of grippers, the determination of permissible accelerations and movement speeds, the actuations for the alignment of components and the accuracy of component deposition, etc. This information is of great importance when designing and optimising industrial assembly systems.