Impact of weld fixture clamp force variation on dimensional integrity in low volume Body-in-White build

Body in White (BIW) is an assembly of multiple sheet metal components. The BIW is the major contributor to the dimensional and structural integrity of an automobile. The accuracy and precision of the BIW is influenced by multiple factors involved in the manufacturing lifecycle of the BIW. Weld fixtures are the tools used for accurately locating and holding sheet metal components during joining. The primary motive of the locating and holding strategy is to arrest all degrees of freedom of a component. Geometric repeatability of the components is also of high importance. Component location is universally achieved by standardized locator pins and mylars that maintain the Principal Location Points (PLP) and Master Control Patches (MCP). In Low volume BIW build employs non-automated clamping methodologies in general, using manual clamps or toggle clamps. This paper studied the dimensional variation of sheet metal assemblies with variation in clamping forces in manual non-automated clamping strategies. Impact of force variation on the dimensional integrity of the assemblies were evaluated using both the strategies. The appropriate clamping strategy is recommended based on the results of the study.