Abstract: A muffler unit includes: an inner cylinder connected with a first exhaust pipe; a first outlet pipe that is connected with a downstream end of the inner cylinder and through which exhaust gas is discharged; an outer cylinder that houses thereinside the inner cylinder and defines, between the outer cylinder and an outer surface of the inner cylinder, an expansion chamber communicating with the second exhaust pipe; and a second outlet pipe that houses thereinside the first outlet pipe and defines, between the second outlet pipe and an outer surface of the first outlet pipe, a path connected with the expansion chamber to thereby be used for discharging the exhaust gas. Accordingly, there is provided the muffler unit having a size reduced compared with a configuration including two mufflers disposed in parallel with each other.

Abstract: An engine exhaust control valve of a saddle-riding vehicle is provided with: a valve shaft disposed in an intersecting manner with a center line of a main pipe portion of an engine exhaust pipe; a valve plate mounted on the valve shaft and rotatably positioned within an inner peripheral surface of the main pipe portion; a valve rotational drive portion mounted on one shaft end of the valve shaft; a drive motor for driving the valve rotational drive portion; and a control unit for controlling the drive motor. Protruding portions with which outer peripheral edges of the valve plate are brought into contact at a rotational limit of the valve plate in a closing direction are formed on an inner peripheral surface of the main pipe portion. The above structure provides a high degree of sealing.

Abstract: In an engine exhaust control valve of a saddle-riding vehicle in which an engine exhaust pipe has a main pipe portion and a branch pipe portion which are connected to an exhaust muffler at downstream sides thereof, a branching portion is provided at which the branch pipe portion is branched sideward from the main pipe portion, and a full-open to full-closed control of the main pipe portion at a downstream side of the branching portion is performed. The exhaust control valve includes: a valve shaft disposed in an intersecting manner with a center line of the main pipe portion; a valve plate mounted on the valve shaft and rotatably positioned within an inner peripheral surface of the main pipe portion; a valve rotational drive portion mounted on one shaft end of the valve shaft; a drive motor for driving the valve rotational drive portion; and a control unit for controlling the drive motor.

Abstract: An exhaust pipe device of a saddle-riding vehicle, wherein a power unit is fixed to a body frame of a saddle-riding vehicle, includes an upstream-side exhaust pipe device for discharging exhaust gas from an internal combustion engine, a catalyst built-in pipe connected to a downstream end of the upstream-side exhaust pipe device, and a downstream-side exhaust pipe device connected to a downstream end of the catalyst built-in pipe. An exhaust muffler is connected to a downstream end of the downstream-side exhaust pipe device. The downstream-side exhaust pipe device has a main pipe portion and a branch pipe portion on a downstream side of an upstream end thereof where a branching portion is provided. An exhaust control valve is provided to the branching portion where the branch pipe portion is branched from the main pipe portion.

Abstract: A muffler unit includes: an inner cylinder connected with a first exhaust pipe; a first outlet pipe that is connected with a downstream end of the inner cylinder and through which exhaust gas is discharged; an outer cylinder that houses thereinside the inner cylinder and defines, between the outer cylinder and an outer surface of the inner cylinder, an expansion chamber communicating with the second exhaust pipe; and a second outlet pipe that houses thereinside the first outlet pipe and defines, between the second outlet pipe and an outer surface of the first outlet pipe, a path connected with the expansion chamber to thereby be used for discharging the exhaust gas. Accordingly, there is provided the muffler unit having a size reduced compared with a configuration including two mufflers disposed in parallel with each other.