Patent ID: 7441545
Filing Date: 2008-10-28
Classification: F02D,F02M,F16K

Abstract:
1. A fuel pressure relief valve configured for use in a fuel system including a fuel pump and a fuel rail that receives pressurized fuel from the fuel pump at an operating pressure, the fuel pressure relief valve comprising: a body defining a passageway therein, the passageway having an inlet end in fluid communication with the fuel pump and an outlet end in fluid communication with the fuel rail such that pressurized fuel flows in a first fuel-flow direction from the inlet end of the passageway to the outlet end of the passageway during fuel pump operation; a seal member moveable between a first position in which the seal member is seated against the outlet end of the passageway, and a second position in which the seal member is unseated from the outlet end of the passageway, the seal member being in the second position during fuel pump operation; and a biasing member biasing the seal member toward the second position; wherein the seal member moves from the second position to the first position immediately after fuel pump shutoff to maintain the pressure in the fuel rail substantially at the operating pressure; and wherein the seal member moves from the first position to the second position when fuel in the fuel rail drops to a residual pressure substantially less than the operating pressure to provide a leak path between the fuel pump and the fuel rail in a second fuel-flow direction opposite the first fuel-flow direction.