Fuel injector

An internal combustion engine comprising a cylinder head having one or more cylinder head bores, and a fuel injection system comprising:

• one or more fuel injectors, the or each fuel injector being mountable in a respective cylinder head bore and each fuel injector including:
• a body region arranged to be received within the cylinder head bore, and a head region arranged to extend outside the cylinder head bore to protrude from the cylinder head when the injector is installed in the cylinder head bore;
• a first valve needle arranged to control the injection of a gaseous fuel from a first outlet;
• a second valve needle arranged to control the injection of a liquid fuel from a second outlet;
• a gaseous fuel inlet for admitting the gaseous fuel to the injector;
• and
• a liquid fuel inlet for admitting the liquid fuel to the injector;
• wherein the gaseous fuel inlet is disposed in the body region of the injector, and wherein the liquid fuel inlet is disposed in the head region of the injector;
• a liquid fuel accumulator volume disposed outside the cylinder head and connected to the liquid fuel inlet of the or each injector;
• and
• gaseous fuel supply means disposed within the cylinder head to supply gaseous fuel to the gaseous fuel inlet of the or each injector.

An internal combustion engine comprising a cylinder head having a plurality of cylinder head bores, and a fuel injection system comprising:

• first and second fuel injectors, each fuel injector mountable in a respective cylinder head bore and each fuel injector including:
• a body region arranged to be received within the cylinder head bore, and a head region arranged to extend outside the cylinder head bore to protrude from the cylinder head when the injector is installed in the cylinder head bore;
• a first valve needle arranged to control the injection of a gaseous fuel from a first outlet;
• a second valve needle arranged to control the injection of a liquid fuel from a second outlet;
• a gaseous fuel inlet for admitting the gaseous fuel to the injector;
• and an accumulator volume for the liquid fuel;
• a liquid fuel inlet for admitting the liquid fuel to the injector;
• wherein the gaseous fuel inlet is disposed in the body region of the injector, and wherein the liquid fuel inlet is disposed in the head region of the injector;
• an accumulator volume for the liquid fuel;
• and
• a liquid fuel outlet in fluid communication with the accumulator volume;
• gaseous fuel supply means disposed within the cylinder head to supply gaseous fuel to the gaseous fuel inlet of each injector;
• wherein the liquid fuel inlet of the first injector is arranged to receive liquid fuel from a high-pressure fuel pump, and wherein the liquid fuel outlet of the first injector is connected to the liquid fuel inlet of the second injector.