The beginning of injection control should alter the injection point depending on the RPMs and/or on the load demand and thus, the start of combustion in the diesel engine.
The front-side cam-disc, together with the roller-ring, controls the beginning of the stroke of the high pressure piston. This point is brought forward if the roller-ring is turned against the rotation direction of the cam-disc. It is connected by a splint to the piston of the injection adjusting device (see figure), which is mounted transversely to the pump-shaft below the casing. On this, the internal pressure from the pump acts on one side, and the force of a spring on the other. The fuel pressure, increasing with the RPMS in the distributing-injection pump, causes, through the injection advance, an up to 20° earlier injection. For the regulation depending on the load, e.g., that depending on the position of the accelerator pedal, the internal pressure is relieved through drillings in the sleeve and in the shaft of the centrifugal governor. Should the driver accelerate, the relief is overridden for a short time through the movement of the centrifugal governor-sleeve, causing the internal pressure to increase.