Fuel pump

摘要

A fuel injection pump includes a pump barrel (12) against (12) against which is located in sealing relationship a valve block (22). A plunger (15) is reciprocably mounted in a bore (14) in the barrel (12) and the valve block (22) contains a spill valve (26) which can spill fuel from the bore (14) during the inward movement of the plunger. An inlet port (21) is formed in the wall of the bore (14) and is uncovered by the plunger (15) during its outward movement. The inlet port communicates with a first annular space (13) defined between the pump barrel and a surrounding pump body (10). The spilled fuel flows through the spill valve into a second annular space (55) defined between the valve block and the body. The first and second annular spaces have a respective inlet and outlet and are substantially isolated from each other.