Title:
HOT EXTRUSION MANDREL OF TUBE WITH INTERNAL FIN
Document Type and Number:
Japanese Patent JPH09271835
Kind Code:
A
Abstract:
To provide a mandrel in order to produce a tube with fins having a precise height without defects over the total length inside the tube with hot extruding.
A glass pool 3 is installed by grooving a stepped part of a mandrel in the circumference direction, plural lines of fin forming grooves 6 are impressed in the axial direction on the mandrel parallel part 4 of hot extrusion, communicating grooves 7 of continuously connected to the fin forming groove 6 are impressed to the glass pool 3 so that an excess glass closed in the fin forming groove 6 is moved to the glass pool 3 and escaped.
Inventors:
KITANI YASUHIKO
HONDA CHIKASADA
HONDA CHIKASADA
Application Number:
JP11014296A
Publication Date:
October 21, 1997
Filing Date:
April 05, 1996
Export Citation:
Assignee:
SANYO SPECIAL STEEL CO LTD
International Classes:
B21C23/10; B21C23/32; B21C25/04; (IPC1-7): B21C25/04; B21C23/10; B21C23/32
Attorney, Agent or Firm:
横井 健至