GB1464890A - Fuel injection pump for an internal combustion engine - Google Patents

Abstract

1464890 Fuel injection pumps BENDIX CORP 28 June 1974 [28 June 1973] 28904/74 Heading F1A A fuel injection pump comprises a plurality of plungers 3, 3A, reciprocable in respective cylinders 4, 4A .... and a pair of electromagnetic spill valves 32, 33 for each pair of cylinders, each having a first position connecting one of its cylinders to a spill passage and a second position connecting the other of its cylinders to a spill passage, whereby alternate changeover of each pair of valves causes delivery from an associated cylinder during the overlapping periods when the valves close both spill passages from a cylinder. The plungers are reciprocated by a cam-shaft 22 which drives a distributor 37 arranged to supply electrical pulses for operating solenoids 17, 23 which actuate the valves 32, 33. Each valve operates every 180 degrees of cam-shaft rotation, the phase relationships of the valve operations to the cam-shaft position determining the timing of injection and the quantity of fuel delivered. The valves 32, 33 are rotatable in a bore in the pump body 18 and include respective axial exhaust bores 13, 25 connected by respective passages 14-16 and 26-28 to a suction chamber 5, the latter being in communication with the cylinders 4, 4A ..... through ports (7) uncovered by the plunger 3, 3A..... during the filling strokes. During a pumping stroke of, e.g. the plunger 3, fuel initially displaced by the plunger 3 flows to the exhaust bore 13 through a passage 30 and slot 8 in the body 18 and an aligned slot 31 in the valve 32. Injection commences when energization of the solenoid 17 closes the slot 31 and continues until de-energization of the solenoid 23 causes alignment of slots 12 and 24 of the valve 33 whereby fuel is then displaced from the cylinder 4 through a passage 9-11 and the slots 12, 24 into the exhaust bore 25. The delivery from the cylinder 4A is controlled in an analogous manner under control of the slots 47, 48 and 52, 53 of the valves 32, 33 respectively.