摘要 |
A fuel injection pump having a mechanically adjustable servo valve for controlling the timing of the pumping event is disclosed. A pivoted lever has one end which engages the spring seat of a timing control plunger servo valve which is also subjected to a speed related hydraulic signal and another end which engages a cam clamped on the throttle shaft to pivot the lever according to the rotational position of the shaft. The profile of the cam is such as to retard the timing of the pumping stroke when the charge delivered by the pump is increased so that pressure built up in the pump is delayed and injection pressure is reached at a substantially constant crankshaft angle regardless of variations in speed and load on the engine. The mechanism is failsafe since it cannot interfere with the movement of the throttle shaft to reduce fuel delivery. |