PURPOSE: To enable inboard controlling pneumatic pressure to be utilized as a drive power source of a hydraulic cylinder so as to reduce the number of parts and decrease cost by supplying inboard controlling pneumatic pressure to a pneumatic hydraulic converter through a pneumatic pressure directional control valve, and supplying hydraulic oil converted therein to a hydraulic cylinder through a solenoid valve unit.

CONSTITUTION: In an electronic governor which is provided with a hydraulic control solenoid valve unit 2 supplying hydraulic oil by changeover to a pair of oil chambers 1a, 1b of a hydraulic cylinder 1 having a rod 11 driving a fuel rack 9 of a diesel engine, and controls the unit 2 by a control unit 5. a pneumatic hydraulic converter 7 having a pair of cylinder parts 7a, 7b to which pneumatic pressure of a pneumatic pressure line 8 for inboard control is supplied through a pneumatic pressure directional control valve 6. The control valve 6 is changed by an electric signal DV from the control unit 5 so as to introduce the inboard controlling pneumatic pressure to the pneumatic hydraulic converter 7, and hydraulic oil enclosed in oil passages 31-34 and the like is pressurized by the pneumatic pressure so as to actuate the hydraulic cylinder 1.