To provide a governor mechanism used for an exhaust control device of an engine and to maintain output in an intermediate rotational region of the engine at a high value.
A fixed cam body 4 is fastened on a governor shaft 3 to rotate by being connected to a crankshaft 2 of an engine, and a movable cam body 5 is fitted on the governor shaft 3 free to move in the axial direction. A plural number of centrifugal weights 6 are clamped between these cam bodies 4, 5. The movable cam body 5 is energized to the side of the fixed cam body 4 by arranging springs 8, 9 which are coil springs of the roughly same shaft center as the governor shaft 3 on the outer peripheral side of the governor shaft 3. The springs 8, 9 are plural and different in winding diameter, and the small diametrical side 9 is arranged inside in the diametrical direction of the large diametrical side 8.