FREEFORM SURFACE MEASUREMENT FOR TOOL CORRECTION

摘要

Forming tools are often used to manufacture freeform surfaces. In free forming, the geometry of the workpiece is fully or partially determined by that of the tool (e.g. forming die). Therefore the quality of the finished product largely depends on the geometry of the tools. Tool geometry, though, is changed in the course of the manufacturing process. Reasons are wear e.g. caused by friction and optimisations carried out manually during tryout. When it is time for repair or manufacture of new tools, there is no record of these geometrical modifications applied to the tools. A model in the form of a closed quality control loop to feed back geometrical modifications to CAD and CAM systems, is presented in this contribution. A means of creating the individual components of the quality control loop is described. Particular care has been taken to ensure that both, the measurement and the feedback are limited to selected areas, in order to minimize the required cost and time.