Verfahren und Vorrichtung zur Herstellung von Löchern am Umfang von Hohlprofilen

摘要

A cutting punch (7) penetrates into the wall of a hollow profile at a high internal pressure, which corresponds to the forming pressure for a hollow blank in the forming tool. This forms an unstable thin area (25) as a breaking point, and weakens the wall. When the punch is retracted, the high internal pressure tears out the profile material around the thin area is retraction direction of the punch, to form the hole. To form a smaller hole, the profile wall is weakened to a higher degree, than for the forming of a larger hole.