Patent ID: 7281520

Claim:
A fuel supply arrangement for supplying fuel to fuel injectors ( 2 ) of an internal combustion engine, comprising a fuel tank ( 3 ), a fuel pumping unit including at least two electrically operated fuel pump ( 4 , 5 ) connected to the fuel tank ( 3 ) by way of a fuel supply line ( 7 ) and to the fuel injectors ( 2 ) via a pressure line ( 8 ) for supplying fuel under pressure to the fuel injectors ( 2 ), a first fuel pump ( 4 ) of the electrically operated fuel pumps ( 4 , 5 ) for providing fuel at a relatively low pressure level suitable for normal engine operation and a second high pressure fuel pump ( 5 ) arranged serially with the first fuel pump ( 4 ) providing fuel at a pressure level higher than the low pressure level for engine operation below a predetermined temperature level during engine startup and warm-up operation, a pressure relief line ( 13 ) connected to the fuel pressure line ( 8 ) downstream of the high pressure pump ( 5 ) for releasing pressurized fuel or supplying low pressure fuel to the injector bypassing the high pressure fuel pump ( 5 ), and means for controlling activation of the high pressure fuel pump ( 5 ) depending on the position of a controllable magnetic blocking valve ( 10 ) arranged in the pressure relief line ( 13 ) for blocking the pressure relief line ( 13 ) when the high pressure fuel pump is activated, and a return line ( 15 ) connected to the pressure line ( 8 ) downstream of the high pressure pump ( 5 ) and including a pressure controller ( 12 ) for returning excess fuel to the upstream side of the high pressure fuel pump ( 5 ) under the control of the pressure controller ( 12 ) for controlling the fuel pressure in the pressure line ( 8 ) during start-up operation, said magnetic blocking valve ( 10 ) being operable for rapid pressure relief in the supply line (B) upon switchover from startup to normal engine operation.