| 摘要 |
PROBLEM TO BE SOLVED: To provide a fluid pipe in which durability of a bent part is improved by eliminating a waste of materials and increase in a manufacturing manhour, and also to increase the durability, miniaturization, and lightening of a water heater applying the pipe. SOLUTION: The wall thickness of an outside round part 612 is set an approximately same to that of a non-bent part 62 in a bent part 61 of the fluid pipe 6, while the wall thickness of an inside round part 611 is set thicker than that of the non-bent part. The wall thickness gradually increases from the upstream side and gradually decreases in the downstream side and the downstream side is formed into thicker than the upstream side. A metal material pipe is bent while applying an axial compression force thereto and the material is plastically fluidized, thereby forming the pipe. COPYRIGHT: (C)2003,JPO
|
