To provide a double-tube type exhaust pipe having small contact area of inner and outer tubes, securing a space between the inner tube and the outer tube even in operation, and preventing reduction of sound insulation effect and heat insulating effect, and a method for easily manufacturing the double-tube type exhaust pipe.
A first projection part 11 always keeping point contact and a second projection part 12 always keeping non-contact are provided on the inner tube 10 of the double-tube type exhaust pipe. Consequently, contact area of the inner and the outer tube is small and the space part S between the inner tube 10 and the outer tube 3 is maintained in operation even if the outer tube 3 is complicatedly bent and curvature is small, and drop of sound insulation effect and heat insulation effect can be prevented.
COPYRIGHT: (C)2005,JPO&NCIPI
Toriaki Watari
Rank
| JP51047057U | ||||
| JP2001289043A | ||||
| JP2000104542A | ||||
| JP52125644U | ||||
| JP57204420U |
Atsushi Nogami
Yasuo Nara
Etsuko Saito
Katsuyuki Utani
Toshifumi Fujii