If one presses the accelerator pedal when a diesel engine is running, as a rule, more fuel is injected. The in-line injection pump regulates, through the injection amount, the effective output of the diesel engine. Should the allowed maximum RPMs be reached, the supply is, if necessary, reduced to the zero, thus, a stable idling RPM is guaranteed.
The volume control occurs, when through the accelerator pedal, the pistons are twisted. This process is supervised by the centrifugal governer. The pistons of the individual pump elements are driven by the camshaft of the fuel injection pump and always carry out the same stroke. The differing supply quantities in the various working conditions of the diesel engine are reached through the milled slots and edges in the pistons. The lower control edge of the pump element piston is arranged at a slant, so that depending on the twist, the conveyor end is reached earlier or later (see figures on the right). All the pistons are mechanically connected with a control rod which, through backward- and forward movement, despite the stroke, can twist all the pistons evenly, thus changing the injection amount. (see figure on the left). This control rod is influenced by the accelerator pedal and the centrifugal governor with a low gear ratio when idling, and a high gear ratio at max. load. The maximum RPM governer springs enable to the centrifugal governor to shift the control rod in the direction of zero supply when the maximum RPMs, regardless of the accelerator pedal position, are exceeded. The much weaker idling springs can compensate RPM surges when the accelerator pedal is not being pressed. 01/10