EXHAUST VALVE DEVICE FOR VEHICLE

An exhaust valve device for a vehicle includes: a valve element axially supported by a rotating shaft in a bore of a valve body produced through casting; sealing projections and integrally formed on an inner circumferential surface of the bore to follow one side portion and the other side portion of an outer circumferential edge of the valve element at a fully closed position; sealing surfaces 21and 22of the sealing projections and the right side portion and the left side portion of the valve element at the fully closed position abutting respectively on the sealing surfaces; R-shaped corners and formed between the inner circumferential surface of the bore and the sealing surfaces and and diameter enlarged portions formed in the inner circumferential surface of the bore to enlarge the bore that are adjacent respectively to the sealing surfaces 21and of the sealing projections and and correspond to lengths of the sealing surfaces and and the valve element has an outer shape enlarged to correspond to a height of the corners and on an outer circumferential side with formation of the diameter enlarged portions at the fully closed position.