Flexible vibration absorbing tube

摘要

A flexible tube includes a bellows tube, an interlock tube placed inside the bellows tube, and upstream-side and downstream-side joint pipes coupled to opposite ends of the bellows tube. Diameters of fixing end portions located at opposite ends of the interlock tube are made larger than a diameter at a middle portion of the interlock tube, extension portions of the upstream-side and downstream-side joint pipes are fitted and fixed to inner peripheral surfaces of the fixing end portions of the interlock tube, and a depth of each of valley portions of a bellows portion of the bellows tube located over the fixing end portions is smaller than a depth of other valley portions of the bellows portion. Accordingly, it is possible to achieve the downsizing of the flexible tube that is connected to an exhaust system being continuous with an engine to dampen vibrations in the axial direction of the exhaust system.

主权项

1. A flexible tube comprising:
a cylindrical bellows tube; a cylindrical interlock tube placed inside the bellows tube; and upstream-side and downstream-side joint pipes respectively coupled to coupling end portions formed at opposite ends of the bellows tube, wherein the bellows tube includes a bellows portion in which ridge portions and valley portions are alternately formed in an axial direction of the bellows tube between the coupling end portions thereof, the upstream-side and the downstream-side joint pipes include respective extension portions each extending from a portion thereof coupled to the bellows tube towards a center of the bellows tube in the axial direction of the bellows tube, the extension portions being fitted and fixed to respective fixing end portions at opposite ends of the interlock tube, the interlock tube is formed such that the fixing end portions thereof are enlarged in diameter as compared with a middle portion of the interlock tube on an inner side in an axial direction of the interlock tube and a diameter of each of the fixing end portions thereof is larger than a diameter of the interlock tube at the middle portion, the extension portions of the upstream-side and the downstream-side joint pipes are fitted and fixed to inner peripheral surfaces of the respective fixing end portions, and depths of the valley portions of the bellows portion that are located over outer peripheral surfaces of the fixing end portions of the interlock tube are smaller than a depth of each of the valley portions of the bellows portion that are located closer to the center of the bellows portion in the axial direction than the valley portions over the fixing end portions.