Method and device for forming a hollow metallic workpiece by inner pressure

US6349583B1 · kind B1 · utility

Assignee

• Benteler Aktiengesellschaft · US

Inventors

• Jürgen Kleinschmidt · Hersbruck, DE
• Dieter Topker · Paderborn, DE
• Elmar Grussmann · Altenbeken, DE

Key dates

• Filing date: Aug 29, 2000
• Grant date: Feb 26, 2002
• Expiry date: Aug 29, 2020

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T29/49805
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

In a method of forming a hollow workpiece having open ends by inner pressure in a multi-part forming tool, the forming tool having a forming mold is heated and the workpiece is placed into the forming mold of the forming tool. Closing plugs are inserted into the open ends of the workpiece, wherein the closing plugs are components of closing cylinders, in order to seal off the open ends. The forming tool is closed. A heated pressure fluid is introduced into the hollow workpiece through at least one of the closing plugs, with the hollow workpiece having been heated and plasticized in the forming tool. The material of the hollow workpiece is pressed with the heated pressure fluid into the forming mold of the forming tool. The device for performing the method has a multi-part forming tool with a forming mold for the workpiece. Hydraulic closing cylinders with closing plugs are provided for sealing the open ends of the workpiece. The forming tool has a heating device for heating at least the forming mold. Heated pressure fluid is introduced into the workpiece through at least one of the closing plugs.