Fuel injection pump having an adjustable inlet poppet valve

Abstract

A fuel injection pump driven by an electric coil, the pump including a poppet valve slidable within a fuel passage in an armature structure and relative thereto in response to movement of the armature structure relative to the pump housing and through a stroke length between a first position permitting flow in a fuel passage from a low pressure fuel chamber to a high pressure fuel chamber, and a second position preventing fuel flow between the high and low pressure fuel chambers, and comprising a head portion located in the high pressure fuel chamber and including a valve surface which is spaced from the valve seat when the poppet valve is in the first position permitting fuel flow from the low pressure fuel chamber to the high pressure fuel chamber, and which is sealingly engaged with the valve seat when the poppet valve is in the second position preventing fuel flow between the high and low pressure fuel chambers, an adjustment member extending in a bore in the housing wall and being engageable with the poppet valve to control the stroke length thereof between the fuel flow permitting and fuel flow preventing positions, and an arrangement for displacing the adjustment member relative to the housing end wall to variably determine the stroke length of the poppet valve.