Fuel recirculation for direct injection fuel system using a high pressure variable venturi pump

Abstract

A high pressure direct injection fuel system includes a low pressure fuel supply; a venturi pump including a variable orifice, first and second inlets and an outlet, the low pressure fuel supply connected to the first inlet of the venturi pump; a high pressure pump connected to the outlet of the venturi pump; a fuel rail connected to an outlet of the high pressure pump, the fuel rail including at least one fuel injector and a pressure sensor; a high pressure regulator connected to the fuel rail; a return flow line connected between the fuel rail and the second inlet of the venturi pump; and an electronic control unit connected to the pressure sensor and the high pressure regulator. The variable orifice venturi pump suppresses gas formation in the return fuel flow thereby allowing the use of a lower fuel supply pressure.

Dependencies are inferred from the claim text.