chapter  11
37 Pages

Fixturing Stiffness and Clamping Stability Verification

Flexible fixturing is an important issue in flexible manufacturing systems (FMS) and computer-integrated manufacturing systems (CIMS). Modular fixtures are the most widely used flexible fixtures in industry. Computeraided modular-fixture design (CAMFD) has been studied (Thompson and Gandhi, 1986). Once a fixture is designed using the CAMFD technique, its performance needs to be evaluated to verify the quality (feasibility and op­ timality) of the fixture design. Fixturing performance may include a locating accuracy for ensuring the tolerance requirement, fixturing stability for se­ curing the locating accuracy during the machining process, fixturing stiffness to resist fixture component deformations, tool-path interference-free, and convenience for design and construction (Rong et al., 1994a). In previous research, the possible interference of the tool and fixture components was graphically checked through a user-computer interface (Berry, 1982), the force equilibrium between cutting and clamping forces were verified for securing the workpiece in the correct position (Trappey and Liu, 1989), the locating rigidity was considered for optimizing the support positions (Chou et al., 1989), and fixture component deformation was studied (Zhu et al., 1993).