A METHODOLOGY FOR APPLYING V-BLOCKS AND CLAMPS TO NONPRISMATIC WORKPART FIXTURES

Most research in computer-aided fixture design (CAFD) aims to develop algorithms to automatically design the fixture configuration of workpi eces. Due to the complexity of nonprismatic geometry, the application domain has been mostly limited to prismatic workpiece fixturing. Moreo ver, based on the 3-2-1 locating principle, the locators employed are mostly restricted to the cylindrical type. This research focuses on an other type of fixture configuration for non-prismatic parts that has b een mostly overlooked. This is to apply V-blocks in workholding to ens ure stable and efficient work setup of non-prismatic parts. The algori thm presented in this paper determines V-block locating by utilising p rojected geometric reasoning. The major steps of the algorithm include candidate-point generation, angle and distance checking, co-ordinate transformation, and interference analysis. Further more, this paper al so explores another algorithm for determining the corresponding clampi ng location of the V-block. The horizontal clamp is planned based on s tatic principles. To ensure workpiece stability, the planning procedur e is classified into three distinct cases according to the force distr ibution and frictional conditions at the contacting regions. These two algorithms, V-block locating and clamp planning, are applied interact ively to obtain the most desired fixture configuration. Finally, an ex ample is provided to explain how these algorithms are applied.