Electronic-mechanical governor for diesel engines

A governor system for a diesel engine, the engine having an accelerator and a fuel-injection pump which has a fuel control rack, the governor system comprising:

• a centrifugal governing means for an upper speed range of the engine, said centrifugal governing means having flyweights displaceable as a function of engine r.p.m. and a shifter movable in response to a displacement of the flyweights;
• an electronic governing means for a lower speed range of the engine, comprising an electromagnetic actuator including an electromagnetic coil, a plunger displaceable in response to the magnetic force of said coil and having a tapered end, a magnetic pole member having an aperture of a conical section corresponding to said tapered end of said plunger for passing said plunger therethrough, and means for permanently urging said plunger in a direction opposite to said magnetic pole member against the magnetic force of said coil;
• and an electronic control circuit means for driving said electromagnetic actuator, comprising means for generating signals individually representing an amount of operation of said accelerator provided in the engine, an engine speed and a position of said plunger, and an amplifier coupled to said signal generating means for supplying a control signal based upon said generated signals to said electromagnetic coil to actuate the same;
• a first coupling means permanently coupling said plunger with said fuel control rack of said fuel-injection pump;
• and
• a second coupling means adapted to connect said shifter of said centrifugal governing means with said control rack to transmit a displacement of said flyweights thereto when the engine speed has exceeded a predetermined speed in said upper speed range of the engine, and to keep said shifter disengaged from said control rack below said predetermined speed.