Outflow Characteristics of a Pressure Medium during Sheet Hydroforming

• Hama Takayuki

  Department of Energy Science and Technology, Kyoto University

• Kurisu Ken

  Department of Energy Science and Technology, Kyoto University Formerly Department of Energy Science and Technology, Kyoto University

• Matsushima Keita

  Department of Energy Science and Technology, Kyoto University

• Fujimoto Hitoshi

  Department of Energy Science and Technology, Kyoto University

• Takuda Hirohiko

  Department of Energy Science and Technology, Kyoto University

Abstract

The outflow characteristics of a pressure medium during a sheet hydroforming process have been studied experimentally by directly measuring the hydraulic pressure distribution. Initial measurements of the outflow of the pressure medium though the gap between two clamped dies were carried out in order to verify the method for measuring the hydraulic pressure distribution employed in this study and to investigate the basic properties of the outflow. The upward forces were calculated by integrating the measured hydraulic pressure during the outflow and found to be in satisfactory balance with the clamping forces, which demonstrates the validity of this measurement method. Furthermore, we suggest that the critical outflow pressure can be predicted by considering the force equilibrium. An experimental investigation of a square-cup sheet-hydroforming process was then carried out. The upward forces were calculated by integrating the measured hydraulic pressure and again found to be in satisfactory balance with the forming forces at the beginning of the process, which shows that the critical outflow pressure can also be predicted for square-cup deep-drawing processes. The hydraulic pressure distributions in the flange area and the chamber change significantly as the sheet conforms to the die shoulder, and the friction loss of hydraulic pressure at the die shoulder becomes large. These results indicate that the magnitude of the fluid-lubrication effect on the drawability of the sheet can vary with the stage of sheet deformation.

Journal

• ISIJ International

  ISIJ International 49 (2), 239-246, 2009

  The Iron and Steel Institute of Japan

Keywords

• press forming
• sheet hydroforming
• deep drawing
• outflow of pressure medium
• pressure distribution

Details

• CRID: 1390282681463036288
• NII Article ID: 10027033244
• NII Book ID: AA10680712
• DOI: 10.2355/isijinternational.49.239
• ISSN: 13475460
• ISSN: 09151559
• Web Site: http://www.jstage.jst.go.jp/article/isijinternational/49/2/49_2_239/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed