Dual-fuel injector

Abstract

A dual-fuel injector for injecting two separate fuels into a combustion chamber of an internal combustion engine includes a nozzle body housing a first fuel needle valve and a second fuel needle valve. The dual-fuel injector further includes a first fuel control chamber defined at least in part by an upper end of the first fuel needle valve such that varying a first pressure in the first fuel control chamber varies the force on the upper end of the first fuel needle valve. Further, the dual-fuel injector includes a second fuel control chamber defined at least in part by an upper end of the second fuel needle valve such that varying a second pressure in the second fuel control chamber varies the force on the upper end of the second fuel needle valve. The dual-fuel injector includes a first fuel control valve defining a first switching volume fluidly coupled to the first fuel control chamber for actuating the first fuel needle valve, and a second fuel control valve defining a second switching volume fluidly coupled to the second fuel control chamber for actuating the second fuel needle valve. The dual-fuel injector further includes an annular hydraulic sealing gallery extending around an outer surface of the first fuel needle valve. The annular hydraulic sealing gallery is fluidly coupled to a source of high-pressure fluid. Additionally, the annular hydraulic sealing gallery is fluidly coupled to at least one of the first switching volume and/or the second switching volume such that the respective switching volume is fluidly coupled to the source of high-pressure fluid via the sealing gallery.

Dependencies are inferred from the claim text.