Falzvergleich: Zangenfalzen vs. Rollfalzen

The requirements for flexibility on joining processes increase with individuality product variation. This trend is mainly focused on the automobile industry. The development of new hemming technologies is necessary for small series in the automobile industry or metalworking industries. Sole alternative to tabletop hemming is currently roller hemming. A robot controlled pliers hemming technology with servo-electrical drive of the hemming jaws creates a new field for higher flexibility and productivity. The purpose of this research project was the systematic study of the process parameters for robot controlled pliers hemming technology for different tasks. In substantial experimental studies the major parameters were identified and characterized. The identification of appropriate process parameters regarding hemming velocity and hemming quality for different geometries was in focus. As a result, the influence of feed velocity and jaws frequency on the quality of the hem flange for steel and aluminum materials was determined on straight and curved component outlines and limitations of the technology were discussed. The studies were supported by analyzes of pliers kinematics at variable hemming parameters. In addition, the influence on adhesive distribution was examined in the hem flange bonding process. One focus was the numerical description of robot controlled pliers in a process model. The simulation results allow an estimation of appropriate hemming parameters with deepened understanding of the process. In the technical comparison, the pliers hemming was compared with roller hemming in terms of fold quality and process times on a curved component outline. With regard to the hem quality of curvature radius and hemming thickness both hemming processes provide comparable results. The folding angle shows slight differences for the processes. Using pliers hemming with high jaws frequency instead of roller hemming a lower roll-in and hence an improved hem quality can be achieved. In cost comparison the technologies tabletop hemming, roller hemming and pliers hemming were compared. Due to consideration of the boundery conditions of the reference scenario, there are significant differences in the cycle times resulting from the respective tool velocity, tool paths and number of process steps. In addition to the comparison of production costs and the suitability of the process was evaluated in terms of technical quality