 | 2013 |
Abstract:
The application of thin-walled profiles made of aluminium alloys generates potentials for optimisation, for example in weight saving. These profiles are used especially in the automotive industry because of their specific material characteristics, such as low density and corrosion resistance. The present work deals with the analysis of flow drilling and thread forming regarding to the angle between workpiece surface and tool axis. The manufacturing process of flow drilling is a forming operation in which the workpiece material is displaced by the flow-drilling tool to generate a bushing in the feed direction. With a subsequent threading operation, in this examination the thread forming, detachable joints between thin-walled profiles can be realised. Previous studies examined the conventional application of the flow-drilling process in which the workpiece surface is in rectangular position to the tool axis. Aim of this work is to expand the capabilities of the flow-drilling process due to different angles of inclination, so that creating of complex joints is possible. In the investigation, using two types of workpieces, the angle between the plane surface of square profiles and the tool axis was modified. Furthermore the distance between the axis of round profiles and the tool axis was varied. In order to quantify the results of the experiments the feed force and the torque were monitored during the flow drilling as well as the thread forming. In addition the circularity and the bore diameter of the formed holes were measured and the quality of the bushings were investigated. To compare the strength of the formed threads, pull-out tests were conducted. As a conclusion of this study the maximal possible angle between the workpiece surface and the tool axis will be recommended.