It is necessary to control the fuel injection volume in accordance with the effort that the accelerator pedal is depressed and engine load as the output of the diesel engine is controlled by the fuel injection volume. Because the injection volume is determined by the spill ring position, it is necessary for the governor to control the spill ring position so that the engine can operate stably.
1. Control according to accelerator depression
Depressed:
The fuel injection volume is increased. (The engine speed is increased.)
Released:
The fuel injection volume is decreased. (The engine speed is decreased.)
2. Control with constant accelerator position and fluctuating engine load
Load increases:
The fuel injection volume is increased.
Load decreases:
The fuel injection volume is decreased. The governor also plays these rolesPrevents the engine from overrunning by controlling the maximum engine speed, and prevents engine stalling by stabilizing the engine speed at low speeds.
Construction and Function
For the mechanical governor, the flyweights, which rotate with the drive shaft of the injection pump, expand outward due to centrifugal force in accordance with the increase of shaft speed. This movement is transmitted to the spill ring through the governor sleeve and control lever to adjust the fuel injection volume.
There are two types of governors:
All-speed governor
M-M (Minimum-Maximum) speed governor