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(11) | EP 1 336 752 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Fuel injection system |
| (57) A fuel injection system for use in an internal combustion engine having an engine
housing comprises two or more unit pumps (18) and a plurality of fuel injectors (26),
each of the unit pumps being received, in use, within a pocket provided in the engine
housing and including a pumping plunger (30) that is reciprocable within a plunger
bore (32) under the influence of a drive arrangement (40, 42, 46), to cause fuel pressurisation
within a pumping chamber (36). Each drive arrangement includes a cam (46) that is
mounted upon a cam shaft of the engine, which extends through the engine housing and
which carries or is formed with the or each of the other cams. An inlet metering valve
arrangement (50) is arranged to control the rate of flow of fuel into each pumping
chamber (36), thereby to control the quantity of fuel to be pressurised within the
pumping chamber during a pumping cycle. An outlet valve arrangement (64) is arranged
to control the delivery of pressurised fuel from the pumping chamber (36) directly
to an accumulator volume (22) through an associated high pressure fuel line (70),
said accumulator volume being arranged to supply pressurised fuel to all of the injectors
(26) of the system. An engine installation incorporating the fuel injection system
and the cam drive arrangement for each unit pump (18) is also provided by the present
invention. |