Jayaweera, N., Kulasekera, A., Maduranga, P., Kasun, T. et al., "A Novel Fixturing Solution for Handling Complex-Shaped Components," SAE Technical Paper 2017-01-2082, 2017.
Many components used in the aerospace industry are complex-shaped, without symmetric axes and parallel surfaces. Fabricating and repairing these components often require fixturing system to support manufacturing processes such as drilling, surface finishing, inspections and assembly. Currently available fixturing systems can be divided into dedicated and flexible fixtures. Among these, the flexible fixtures are suitable for rapidly changing fabricating processes and handling several complex-shaped components using same fixturing system. Background research suggested that the pin type fixturing system is the predominant design used in such applications to fix complex-shaped components. In pin type fixturing systems, force is applied to a single point of contact. This increases the pressure applied to the work piece and possibility of damaging these components. Further, conventional pins use rigid designs, which cannot adapt to the shape of the work piece. This reduces the applicable clamping force and the increases the possibility of slipping. This paper describes a fixturing system to address these problems by developing a distributed force fixing method with conformance to complex shapes. Proposed fixturing system uses jamming granular materials with negative pressure. A flexible rubber container fill with granular material is attached to the tip of a modified pin. When the container touches the work piece it conforms to the shape of the work piece. Then the rubber container vacuumed, which rigidifies the container and fix the shape, through granular jamming. Series of experiments were carried out to decide the best suited granular material in terms of highest holding force with best adaptability to a complex surface. Experiments were carried out using eight different low cost locally sourced materials. According to the experimental results proposed system successfully provide required holding forces to manipulate complex shaped components.