Computer-aided fixture design system with process planning integration for prismatic parts manufactured on CNC machining centers

Abstract

Jigs and fixtures are indispensable tools in various manufacturing processes. These processes include metal removal, assembly, welding, and inspection processes. Not only do jigs and fixtures facilitate the operations, but also provide quick loading/unloading, proper and consistent supporting and locating of a workpiece. As a result, the workpiece can be manufactured economically in proportion to the volume of production. With the advent of computer aided design and computer aided manufacturing together with an increasing power of both computer hardware and software, computerized fixture design systems become feasible and more sophisticated. The current computerized fixture design systems are developed utilizing several approaches ranging from simple interactive placement of fixture components to sophisticated generative systems. However, one of the common drawbacks of these systems is a lack of process planning integration in the fixture design considerations. As a result, the contradiction between fixture design generated by the computerized fixture design system and a process plan generated by a process planner or by computer aided process planning software always occurs. In other words, the fixture set-ups and workpiece orientation are not congruent to the process plan. This paper serves to discuss a solution to the problem mentioned above. A mathematical model was developed to integrate process planning in fixture design considerations. An optimized fixture design system will be presented and discussed. Examples of tested cases are also presented.