COMBINED FORWARD-BACKWARD EXTRUSION WITH CONTROLLED REVERSAL RAM MOTION -Effect of Reversal Ram Motion-

  • Hanami S. (Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University) ;
  • Matsumoto R. (Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University) ;
  • Otsu M. (Department of Mechanical Engineering and Materials Science, Faculty of Engineering, Kumamoto University) ;
  • Osakada K. (Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University) ;
  • Hayashida D. (Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University)
  • Published : 2003.10.01

Abstract

In combined forward-backward extrusion with controlled forward speed by a counter punch, accurate parts with forward rod can be formed. As an extension of this method, reverse extrusion is proposed, in which the extruded forward rod is pushed back while the main punch is kept at the final position after the forward-backward extrusion process. The experiment is carried out using lead as a model material. With the reverse extrusion method, longer forward rods can be formed without under-filling defect than that by combined extrusion with controlling extrusion speed.

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