Abstract: A flexible pipe unit for an exhaust pipe line of an internal combustion engine comprises a metal bellows which has a front open end adapted to be connected to a first exhaust pipe and a rear open end adapted to be connected to a second exhaust pipe. A cylindrical outer case of metal is coaxially disposed about the metal bellows in a manner to define therebetween a cylindrical space. A first structure is arranged between a front end of the outer case and a front end of the bellows to achieve a mechanical connection therebetween. A second structure is arranged between a rear end of the outer case and a rear end of the bellows to achieve a mechanical connection therebetween. At least one of the first and second structures comprises a spring member by which the bellows and the outer case are resiliently connected.

Abstract: A circular plate spring for use in a flexible pipe unit comprises an annular base portion constructed of a spring metal plate and a plurality of equally spaced resilient support portions integral with the annular base portion. The resilient support portions are raised from the annular base portion so that each support portion is inclined relative to an imaginary plane on which the annular base portion lies.