Improvement to a fuel-injection system for an internal-combustion engine

摘要

The injection system comprises a high-pressure pump (7) with variable flowrate, having at least one pumping element (18) provided with an intake valve (25) in communication with an intake pipe (10) and a delivery valve (30) in communication with a delivery pipe (8). A pressure regulator (32) is set on the intake pipe (10) downstream of a metering solenoid valve (27) designed to meter the flowrate of the pump (7) according to the operating conditions of the engine. The pressure regulator (32) is designed to discharge the excess fuel into a compartment (35) of a crankcase (33) for lubricating the usual actuation mechanism (26) of the pumping element. Set between an inlet (29) of the solenoid valve (27) and an inlet (34) of the pressure regulator (32) is a control volume (37) designed to contain an amount of fuel such as to guarantee an adequate flow of fuel in an area corresponding to the inlet (29) of the solenoid valve (27).