A fuel injection system includes a first high pressure fuel source, a return channel connected to a second low pressure fuel source, a residual pressure regulator having an inlet and an outlet connected to the return channel, and a fuel injector having a control valve arrangement comprising an inlet, an outlet and a return port, a fuel injection nozzle having an outlet chamber, an injection outlet, and a needle member in the outlet chamber. The needle member is biased to a closed position to block fluid communication between the outlet chamber and the injection outlet, and to open fluid communication by a pressure in the outlet chamber. The residual pressure regulator is connected to a spill valve to regulate pressure to a residual pressure higher than the pressure in the return channel and lower than the pressure of the first fuel source.

A fuel injection system is provided. The fuel injection system can have a fuel injector having a check valve with a plurality of fuel output ports, and a fuel injector body with an outer surface and an inner surface. The fuel injector body defines an inner volume to accommodate bi-directional movement of the check valve. The fuel injector body includes at least a first row of injection ports and a second row of injection ports extending from the inner surface to the outer surface. The check valve is bi-directionally controllable in the inner volume, during a single cycle, to output from the fuel injector body any one of a plurality of predefined pulse injection patterns.

The invention relates to a fuel injection valve comprising a housing (1) in which pressure is applied to a nozzle needle (8), in a control chamber (28), at least indirectly with a closing force in the direction of a valve seat (10). The pressure in the control chamber (28) can be adjusted using a control valve (40) as said control chamber (28) is able to be connected to a low pressure chamber (46) via an outlet restrictor (31) and be filled with fuel at high pressure via an inlet restrictor (30). A longitudinally-displaceable control piston (29) is arranged in the control chamber (28) and divides said chamber (28) into a first control sub-chamber and a second control sub-chamber (228), the first control sub-chamber (128) being able to be connected to the low pressure chamber (46) by means of said outlet restrictor (31). A sealing surface (38) is formed on the control piston (29) and interacts with a sealing seat (39) in the control chamber (28) such that the inlet restrictor (30) is hydraulically disconnected from the second control sub-chamber (228) when the sealing surface (38) comes to rest against the sealing seat (39). Said first control sub-chamber (128) and second control sub-chamber (228) are constantly hydraulically interconnected by means of a restrictor connection (34).

An injecting apparatus for injecting a fluid under pressure into an associated chamber, the injecting apparatus including: a body, a piston movable in the body under the action of fluid pressure in the associated chamber acting from externally against the piston, the piston being operable to compress fluid to be injected in a high pressure chamber, the piston being movable against the action of fluid pressure in a control chamber whereby movement of the piston is selectively controllable by controlling the fluid in the control chamber, an injector valve and an associated injector orifice in selective fluid communication with the high pressure chamber whereby high pressure fluid from the high pressure chamber can be injected through the injector orifice upon opening of the injection valve.

A dual fuel system for an internal combustion engine includes a first fuel supply of a liquid pilot fuel, a primary fuel supply of a liquid primary fuel, and a dual fuel injector. The dual fuel injector includes a spill valve fluidly connected with a plunger cavity and movable to control a start of injection and an end of injection, and an admission valve. The admission valve is movable to admit a pilot fuel into the fuel injector, such that the pilot fuel is conveyed through an outlet check to form, within a primary fuel passage fluidly connected to the plunger cavity, a segmented fuel charge of leading pilot fuel and trailing primary fuel by displacing some of the primary fuel. The liquid pilot fuel may be a higher cetane/lower octane liquid fuel, and the primary fuel may be a lower cetane/higher octane liquid fuel.

A dual fuel system for an internal combustion engine includes a first fuel supply of a liquid pilot fuel, a primary fuel supply of a liquid primary fuel, and a dual fuel injector. The dual fuel injector includes a spill valve fluidly connected with a plunger cavity and movable to control a start of injection and an end of injection, and an admission valve. The admission valve is movable to admit a pilot fuel into the fuel injector, such that the pilot fuel is conveyed through an outlet check to form, within a primary fuel passage fluidly connected to the plunger cavity, a segmented fuel charge of leading pilot fuel and trailing primary fuel by displacing some of the primary fuel. The liquid pilot fuel may be a higher cetane/lower octane liquid fuel, and the primary fuel may be a lower cetane/higher octane liquid fuel.

A dual fuel system for an internal combustion engine includes a first fuel supply of a liquid pilot fuel, a primary fuel supply of a liquid primary fuel, and a dual fuel injector. The dual fuel injector includes a spill valve fluidly connected with a plunger cavity and movable to control a start of injection and an end of injection, and an admission valve. The admission valve is movable to admit a pilot fuel into the fuel injector, such that the pilot fuel is conveyed through an outlet check to form, within a primary fuel passage fluidly connected to the plunger cavity, a segmented fuel charge of leading pilot fuel and trailing primary fuel by displacing some of the primary fuel. The liquid pilot fuel may be a higher cetane/lower octane liquid fuel, and the primary fuel may be a lower cetane/higher octane liquid fuel.

A dual fuel system for an internal combustion engine includes a first fuel supply of a liquid pilot fuel, a primary fuel supply of a liquid primary fuel, and a dual fuel injector. The dual fuel injector includes a spill valve fluidly connected with a plunger cavity and movable to control a start of injection and an end of injection, and an admission valve. The admission valve is movable to admit a pilot fuel into the fuel injector, such that the pilot fuel is conveyed through an outlet check to form, within a primary fuel passage fluidly connected to the plunger cavity, a segmented fuel charge of leading pilot fuel and trailing primary fuel by displacing some of the primary fuel. The liquid pilot fuel may be a higher cetane/lower octane liquid fuel, and the primary fuel may be a lower cetane/higher octane liquid fuel.

A two-position gate valve has a gate defining a full-flow passageway therethrough and defining a restricted-flow passageway therethrough, without defining a closed position. The full-flow passageway has an entrance with a first area and an exit with a second area, the second area being smaller than the first area, and the full-flow passageway continuously tapers from the entrance to the exit thereof. The restricted-flow passageway has an entrance with a third area and has an exit with a fourth area, the fourth area being smaller than the first area, the second area, and the third area, and the restricted-flow passageway continuously tapers from the entrance to the exit thereof. Flow through the full-flow passageway is in a first direction and flow through the restricted-flow passageway is also in the first direction and the ratio of the fourth area to the second area is in a range of 5 to 15.

The invention relates to a fuel injector arrangement (1) comprising a number of fluid supply paths (29, 31, 39), namely, a first (29), a second (31) and a third fluid supply path (39). The fuel injector arrangement (1) has a first switching device (43) in the second fluid supply path (31). Said first switching device, controlled by the fluid pressure in the third fluid supply path (39), opens or blocks the second fluid supply path (31). The fuel injector arrangement (1) has a second switching device (49) in the first fluid supply path (29). Said second switching device, controlled by the fluid pressure downstream of the first switching device (43) in the second fluid supply path (31), opens or blocks the first fluid supply path (29).