| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for bending a pipe and a core metal used for the bending which realize suppression of the wrinkle at the inside of the bending part and the flattening and the breakage at the outside of the bending part and also realize such bending of the minimum radius that the radius in the curvature at the inside of the bending part come close to zero endlessly by using only low-cost general press-bending excellent in mass-productivity. SOLUTION: The pipe bending method for bending the pipe by setting the pipe into which the core metal is inserted between a projecting die for bending and a recessing die for bending mutually opposite to each other and arranged in a pressing machine and pressurizing the projecting die for bending and the recessing die for bending, is characterized in that the core metal is turned around the bending center in the center axis of the pipe synchronously with the pressurization of the projecting die for bending and the recessing die for bending. Further, two bar-like core metals closely contacting with the inner surface of the pipe to be bent is used, wherein a connection member is provided at each the distal end of the core metal and the two core metals are turned around the turning center of the connection means in the bending. COPYRIGHT: (C)2005,JPO&NCIPI
|
