Abstract: A fuel injector includes a nozzle having at least one nozzle outlet. A valve needle is moveable with respect to a valve needle seating through a range of movement between a closed position and an open position to control fuel delivery through the at least one nozzle outlet. The movement of the nozzle needle is controlled by fuel pressure within a control chamber. The injector has first and second nozzle control valves for controlling fuel flow into and out of the control chamber to pressurise and depressurise the control chamber, respectively. The first nozzle control valve can operate selectively to place the control chamber in fluid communication with a fuel drain or to place the control chamber in fluid communication with a high pressure supply line. The second nozzle control valve can operate selectively to place the control chamber in fluid communication with a fuel drain.

Abstract: The present application relates to a pump unit for a fuel injection system. The pump unit has a low pressure fuel supply line and a high pressure fuel outlet. A pumping chamber having a plunger is operable to perform a pumping cycle comprising a pumping stroke and a filling stroke. The pump unit also includes an inlet valve having an inlet valve member movable between an open position for permitting the supply of fuel to the pumping chamber from the low pressure fuel supply line and a closed position for inhibiting the supply of fuel from the pumping chamber to the low pressure supply line. An outlet valve is provided in the high pressure fuel outlet. The pump unit also includes a means for latching the inlet valve member in its open position. The present application also relates to a method of operating a pump unit.

Abstract: A fuel injector for use in delivering fuel to an internal combustion engine includes a nozzle having a valve needle which is moveable with respect to a valve needle seating through a range of movement between a fully-closed position and a fully-open position to control fuel delivery through at least one nozzle outlet, whereby movement of the nozzle needle is controlled by fuel pressure within a control chamber. A nozzle control valve controls fuel flow into and out of the control chamber to pressurize and depressurize the control chamber, respectively. The fuel injector also includes a variable flow passage in communication with the control chamber through which fuel flows out of the control chamber at a variable rate throughout the range of movement of the valve needle so that movement of the valve needle is damped to a greater extent as it approaches the fully-open position.

Abstract: Fuel injection equipment includes a high pressure fuel source able to flow high pressure fuel via connecting pipes to a plurality of injectors. The fuel injection equipment is high pressure fuel reservoir-less, a distributed storage for high pressure fuel being arranged in the pipes and in the injectors.

Abstract: A fuel injector includes a nozzle having at least one nozzle outlet. A valve needle is moveable with respect to a valve needle seating through a range of movement between a closed position and an open position to control fuel delivery through the at least one nozzle outlet. The movement of the nozzle needle is controlled by fuel pressure within a control chamber. The injector has first and second nozzle control valves for controlling fuel flow into and out of the control chamber to pressurise and depressurise the control chamber, respectively. The first nozzle control valve can operate selectively to place the control chamber in fluid communication with a fuel drain or to place the control chamber in fluid communication with a high pressure supply line. The second nozzle control valve can operate selectively to place the control chamber in fluid communication with a fuel drain.

Abstract: Fuel injection equipment includes a high pressure fuel source able to flow high pressure fuel via connecting pipes to a plurality of injectors. The fuel injection equipment is high pressure fuel reservoir-less, a distributed storage for high pressure fuel being arranged in the pipes and in the injectors.

Abstract: An actuator arrangement for an electromagnetically operated fuel injector includes a pole member having a first end face and defining an aperture extending from the first end face and an actuator core received within the aperture. The actuator core carries at least one contact member having a contact face that is exposed through the aperture. An encapsulating member is received within the aperture and surrounds the at least one contact member. The first end face of the pole member, the contact face and the encapsulating member are arranged to provide the actuator arrangement with a substantially planar surface for mating with an adjacent component, in use.

Abstract: A fuel injector comprising a valve needle for controlling fuel injection through an injector outlet, a control chamber for receiving fuel and a three-way control valve that controls fuel pressure within the control chamber to control opening and closing movement of the valve needle to control fuel injection through the outlet. The three-way control valve controls communication between (a) a first passage and a second passage and (b) a third passage and the second passage, and includes a first housing provided with a guide bore for a control valve member, whereby movement of the control valve member is guided within the guide bore and a first valve seat, defined by a second housing, with which an end of the control valve member is engageable to control communication between the first and second passages. The first housing is a control valve housing and the second housing is an injector housing, the injector housing being provided with a guide bore for the valve needle or a part carried by the valve needle.

Abstract: An actuator arrangement for an electromagnetically operated fuel injector includes a generally cylindrical actuator core having a longitudinal axis and defining an inner pole face of the actuator arrangement. The actuator core is formed of a bespoke magnetic material. A wire coil is disposed around the actuator core arranged to be connected to a power source to generate a magnetic field around the coil. A pole member is formed of a high strength material and defines an aperture for receiving the actuator core. The pole member defines an outer pole face of the actuator arrangement substantially co-planar with the inner pole face. An armature is movable in a direction parallel to the longitudinal axis in response to the magnetic field. The magnetic field passes into the armature in the region of the inner pole face and into the armature in the region of the outer pole face.

Abstract: The present application relates to a pump unit for a fuel injection system. The pump unit has a low pressure fuel supply line and a high pressure fuel outlet. A pumping chamber having a plunger is operable to perform a pumping cycle comprising a pumping stroke and a filling stroke. The pump unit also includes an inlet valve having an inlet valve member movable between an open position for permitting the supply of fuel to the pumping chamber from the low pressure fuel supply line and a closed position for inhibiting the supply of fuel from the pumping chamber to the low pressure supply line. An outlet valve is provided in the high pressure fuel outlet. The pump unit also includes a means for latching the inlet valve member in its open position. The present application also relates to a method of operating a pump unit.

Abstract: A fuel injector includes a nozzle having at least one nozzle outlet. A valve needle is moveable with respect to a valve needle seating through a range of movement between a closed position and an open position to control fuel delivery through the at least one nozzle outlet. The movement of the nozzle needle is controlled by fuel pressure within a control chamber. The injector has first and second nozzle control valves for controlling fuel flow into and out of the control chamber to pressurise and depressurise the control chamber, respectively. The first nozzle control valve can operate selectively to place the control chamber in fluid communication with a fuel drain or to place the control chamber in fluid communication with a high pressure supply line. The second nozzle control valve can operate selectively to place the control chamber in fluid communication with a fuel drain.

Abstract: A control valve, for use in controlling fuel pressure within a control chamber, comprises a control valve member, first flow restriction and second flow restriction. The control valve member is movable between a first position, and a second position. The first flow restriction is arranged to maintain a first pressure upstream of the first flow restriction when the control valve member is in transition between the first position and the second position. The second flow restriction is positioned downstream of the first flow restriction and is arranged to maintain a second pressure upstream of the second flow restriction. The second flow restriction is dimensioned and located relative to the first flow restriction such that in transition between the first and second positions the net force exerted on the control valve member by the first pressure balances the net force exerted on the control valve member by the second pressure.

Abstract: A fuel injector for use in delivering fuel to an internal combustion engine includes a nozzle having a valve needle which is moveable with respect to a valve needle seating through a range of movement between a fully-closed position and a fully-open position to control fuel delivery through at least one nozzle outlet, whereby movement of the nozzle needle is controlled by fuel pressure within a control chamber. A nozzle control valve controls fuel flow into and out of the control chamber to pressurise and depressurise the control chamber, respectively. The fuel injector also includes a variable flow passage in communication with the control chamber through which fuel flows out of the control chamber at a variable rate throughout the range of movement of the valve needle so that movement of the valve needle is damped to a greater extent as it approaches the fully-open position.

Abstract: An actuator arrangement for an electromagnetically operated fuel injector includes a pole member having a first end face and defining an aperture extending from the first end face and an actuator core received within the aperture. The actuator core carries at least one contact member having a contact face that is exposed through the aperture. An encapsulating member is received within the aperture and surrounds the at least one contact member. The first end face of the pole member, the contact face and the encapsulating member are arranged to provide the actuator arrangement with a substantially planar surface for mating with an adjacent component, in use.

Abstract: An actuator arrangement for an electromagnetically operated fuel injector, includes a generally cylindrical actuator core having a longitudinal axis and defining an inner pole face of the actuator arrangement. The actuator core is formed of a bespoke magnetic material. A wire coil is disposed around the actuator core arranged to be connected to a power source to generate a magnetic field around the coil. A pole member is formed of a high strength material and defines an aperture for receiving the actuator core. The pole member defines an outer pole face of the actuator arrangement substantially co-planar with the inner pole face. An armature is movable in a direction parallel to the longitudinal axis in response to the magnetic field. The magnetic field passes into the armature in the region of the inner pole face and into the armature in the region of the outer pole face.

Abstract: A fuel injector comprising a nozzle having a nozzle needle which is moveable with respect to a first needle seat to control fuel delivery through a nozzle outlet. The injector includes a nozzle control valve for controlling fuel flow into a control chamber through a first passage to pressurise the control chamber, and for controlling fuel flow out of said control chamber through said first passage to depressurise the control chamber. Movement of the nozzle needle is controlled by fuel pressure within the control chamber, such that pressurising the control chamber causes the nozzle needle to be urged against the first needle seat to close the nozzle outlet, and depressurising the control chamber causes the nozzle needle to lift from the first needle seat to open the nozzle outlet. The nozzle needle defines, at least in part, a restricted passage through which fuel can flow into the control chamber as the control chamber depressurises.

Abstract: A fault detector for detecting valve movement of a valve in a fuel injector of an engine system, the valve includes an electromagnetic actuator arranged to move the valve between first and second valve positions, the engine system includes a sensor for sensing a current through the actuator. The detector includes a controller arranged to control the sensor; receive sensor data related to the current through the actuator; analyze the received data for current discontinuities; and output a valve movement signal dependent upon the current discontinuities. The controller is arranged to sense current during a finite sampling window, move the sampling window from a first window position to a later window position for one or more subsequent injection events; determine a new sampling window position on based a valve movement signal output the two preceding windows; and feedback the new sampling window position for a subsequent injection event.

Abstract: A fuel injector comprising a valve needle for controlling fuel injection through an injector outlet, a control chamber for receiving fuel and a three-way control valve that controls fuel pressure within the control chamber to control opening and closing movement of the valve needle to control fuel injection through the outlet. The three-way control valve controls communication between (a) a first passage and a second passage and (b) a third passage and the second passage, and includes a first housing provided with a guide bore for a control valve member, whereby movement of the control valve member is guided within the guide bore and a first valve seat, defined by a second housing, with which an end of the control valve member is engageable to control communication between the first and second passages. The first housing is a control valve housing and the second housing is an injector housing, the injector housing being provided with a guide bore for the valve needle or a part carried by the valve needle.

Abstract: A control valve arrangement for use in controlling fuel pressure within a control chamber (30) includes a control valve member (32) which is movable between a first position in which the control chamber (30) communicates with a source of high pressure fuel, and a second position in which the control chamber (30) communicates with a low pressure fuel drain and communication between the control chamber (30) and the source of high pressure fuel is broken. The control valve arrangement also includes restricted flow means (55, 70, 86) for restricting the rate of flow of fuel from the control chamber (30) to the low pressure fuel drain when the control valve member (32) is moved from the first position to the second position.

Abstract: A control valve, for use in controlling fuel pressure within a control chamber, comprises a control valve member, first flow restriction and second flow restriction. The control valve member is movable between a first position, and a second position. The first flow restriction is arranged to maintain a first pressure upstream of the first flow restriction when the control valve member is in transition between the first position and the second position. The second flow restriction is positioned downstream of the first flow restriction and is arranged to maintain a second pressure upstream of the second flow restriction. The second flow restriction is dimensioned and located relative to the first flow restriction such that in transition between the first and second positions the net force exerted on the control valve member by the first pressure balances the net force exerted on the control valve member by the second pressure.