Title:
MANDREL FOR EXTRUDING PIPE WITH FINS AND ITS EXTRUDING METHOD
Document Type and Number:
Japanese Patent JP2524037
Kind Code:
B2
Abstract:
PURPOSE: To manufacture a pipe with fins in the inner surface having high dimensional accuracy without any recessed defect and protruding defect.
CONSTITUTION: By using a mandrel, in which a part faced to a fin forming part in a die is chamfered in the range of about 1/2 at the front end side in the forming part having length (1) of a mandrel for hot extrusion and above part is not chamfered in the range of about 1/2 at the rear end side, the extrusion work is executed.
Inventors:
TOKUNAMI YOSHIFUMI
TAKAMURA YOSHINOSUKE
TANABE ISAO
TAKAMURA YOSHINOSUKE
TANABE ISAO
Application Number:
JP32591691A
Publication Date:
August 14, 1996
Filing Date:
December 10, 1991
Export Citation:
Assignee:
SHINNIPPON SEITETSU KK
International Classes:
B21C23/10; B21C25/04; (IPC1-7): B21C25/04; B21C23/10
Domestic Patent References:
| JP4274817A | ||||
| JP54180442U |
Attorney, Agent or Firm:
Tomoyuki Yathata (1 outside)