IC engine fuel injection pump - has membrane forming wall of damping chamber braking plunger delivery stroke

摘要

The engine fuel-injection pump has a cam-driven plunger also turning in its barrel, drawing in fuel from a feed chamber and discharging via a pressure pipe to an injector. Cessation of injection is controlled by a spill port uncovered by the plunger, whose delivery stroke is then braked hydraulically by a damping chamber connected to the feed chamber. One wall of the damping chamber (36) is formed by a membrane (38), snd the plunger (13) is shaped so that near top dead-centre position of the cam the connection between damping and feed (18) chambers is shut off. ADVANTAGE - No need for close concentricity between plunger and chamber.