IMPROVEMENTS RELATING TO FUEL PUMPS

摘要

A pump head suitable for use in a fuel pump for a common rail fuel injection system, comprises a pump head housing (110) defining a plunger bore (118) and a pumping chamber. (124) Fuel is pressurised within the pumping chamber (124) by a plunger (116) reciprocating within the plunger bore. The pump head housing (110) includes an inlet valve arrangement (132) for controlling fuel flow into the pumping chamber. (146) The inlet valve arrangement includes a valve member moveable between open and closed positions in response to fuel pressure within a gallery (150). The gallery (150) communicates with an external chamber (168) defined by a closure means externally mounted to the pump head housing. (110) In use, the gallery (150) communicates with a source of low-pressure fuel via the external chamber. The pump head housing has a projection (112a) which locates the closure member on the pump head housing (110).