Split-line design for given geometry and location schemes

The spatial relations between parts in an assembly can be critical for the functional and aesthetic quality of a product. In the case of the automobile, these relations can be between doors, fenders, hood, panels, and so on. Variation in these relations, caused by part and assembly variation, influences the output variation, which is what the customer sees and judges. This paper presents a computer-aided tolerancing tool that supports and improves split-line design with respect to geometrical variation. A split-line is the relation between two mating parts over a distance. The design and placement of a split-line in an automobile body are influenced by several aspects such as design language, geometrical dimensioning, crash safety, and so on. In this paper only the geometrical dimensioning aspects have been considered. The research has been carried out using simulations and analyses in a computer-aided tolerancing software. The tool presented describes a way to calculate and visualize the geometrically most robust area and split-line between two parts. The findings from the research show that it is difficult to calculate and visualize the result in flush and gap directions in the same way. The tool gives insight into how the configuration of the locating schemes influences the geometrical robustness of the design.