Title:
ENDING METHOD OF METALLIC PIPE
Document Type and Number:
Japanese Patent JPH1157871
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To easily remove a core material by inserting the coil spring-like core material into the inside of the metallic pipe and bending the pipe in such a state. SOLUTION: In bending processing, first a cylindrical coil spring-like core material 2 is inserted into the bending part of the metallic pipe 1 so that the metallic pipe 1 is confined by the coil material 2 and bent to be a given shape. Then, the coil spring of the core material 2 is twist rotated along the twist rotation direction and pulled out while the diameter of the coil spring is decreased. Furthermore, the core material 2 has the flexibility that can follow the bending operation and the outside diameter almost same as or slightly smaller than the inside diameter of the metallic pipe 1, but the diameter difference is in a range not to form the space which generates the locally bending to the metallic pipe 1 at the time of bending processing.
Inventors:
SUEMORI SEIZO
Application Number:
JP22666597A
Publication Date:
March 02, 1999
Filing Date:
August 22, 1997
Export Citation:
Assignee:
SEKISUI HOUSE KK
International Classes:
B21D9/01; (IPC1-7): B21D9/01
Attorney, Agent or Firm:
Mitsuhiko Watanabe