Patent ID: 6151893
Filing Date: 2000-11-28
Classification: F01N,F16L

Abstract:
A flexible tube for an automobile exhaust system, which is provided with a bellow assembly (3) whose both longitudinal ends are connected respectively to a first exhaust pipe (1) and a second exhaust pipe (2) to absorb vibrational displacement of both exhaust pipes (1), (2), and with a surrounding member which is so installed as to cover the outer periphery of said bellows (3) to protect said bellows (3) and prevent said bellows (3) from over-extending, being characterized in that:said bellow assembly (3) has central accordion like components or bellows and cylinders formed at their both ends; andsaid surrounding member consists of:a. a first collar (7') and a second collar (7"") which are respectively connected to the outer periphery of both ends of cylindrical portions (3b) of said bellow assembly (3), said first collar and second collar comprising:installed portions (7b'), (7b"") which are connected to the outer periphery of both ends (1c), (2c) of said first exhaust pipe (1) and said second exhaust pipe (2); andrisers (7a'), (7a"") bent toward the inner side of said outer cover (5) from bellow component (3a) of the installed portions (7b') and (7b"");b. a first elastic stopper member (8') and a second elastic stopper member (8"") which are provided along the installed portions (7b'), (7b"") comprising:elongated portions (8b'), (8b"") which elongate from the risers (7a'), (7a"") to the side of the outer cover (5);an outer peripheral surface (8a'), (8a"") of said elongated portions (8b'), (8b"") which contacts and supports an inner surface of both ends of the outer cover (5); anda gap (t1) disposed between the inner surface of both ends of the outer cover (5) and the risers (7a'), (7a"");c. a first elongation displacement stopper member (6') and a second elongation displacement stopper member (6"") which are integrally formed at both ends of said outer cover (5) and are elongated from said both ends of the outer cover (5) towards the central axis of the first exhaust pipe (1) and the second exhaust pipe (2), and there is a gap (t4) between ends (6a'), (6a"") of both elongation displacement stopper members (6'), (6"") and said installed portions (7b'), (7b"") of both collars (7'), (7""); andwhereby gaps (t1), (t4), (t5) are formed between members a, b, and c above, with the gaps (t1), (t4), (t5) allowing said first exhaust pipe (1) and said second exhaust pipe (2) to move freely without restriction by the outer cover (5), the first elongation displacement stopper member (6') or the second elongation displacement stopper member (6""), and such displacement of the exhaust pipes is absorbed, in accordance with uniform deformation characteristics, enough to deform the bellows (3) as a whole, upon such vibration as to give a pipe-axis-directional, bending-directional or shear-directional displacement to said first exhaust pipe (1) and said second exhaust pipe (2) from a engine or a car body.