Abstract: A fuel injector comprises a supply means for high pressure fuel, an injection nozzle including a valve needle engageable with a valve needle seating to control fuel delivery from the injector, a first filling flow path providing flow from the supply means into a control chamber, and a control valve for controlling fuel pressure within the control chamber. The control valve comprises a control valve member slidable within a guide bore of a valve housing. The injector further comprises a drain flow path including a drain restriction and permitting flow from the control chamber to a second valve chamber when the control valve member is in a second state, and a second filling flow path permitting flow from a first valve chamber into the control chamber when the control valve member is in a first state, wherein the second filling flow path bypasses the drain restriction.

Abstract: A needle for use in a needle valve, such as the needle valve of a fuel injector, comprises a tip section (2), a first guide section (1a) and a second guide section (3). The tip section (2a) has a needle tip. The first guide section (1a) is remote from the needle tip. The second guide section comprises a tube, wherein the first guide section (1a) and the tip section (2a) are comprised in an integrated inner needle component (7) extending through the tube (3). A method of manufacturing such a needle is also described.

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 fuel injector comprises a supply means for high pressure fuel, an injection nozzle including a valve needle engageable with a valve needle seating to control fuel delivery from the injector, a first filling flow path providing flow from the supply means into a control chamber, and a control valve for controlling fuel pressure within the control chamber. The control valve comprises a control valve member slidable within a guide bore of a valve housing. The injector further comprises a drain flow path including a drain restriction and permitting flow from the control chamber to a second valve chamber when the control valve member is in a second state, and a second filling flow path permitting flow from a first valve chamber into the control chamber when the control valve member is in a first state, wherein the second filling flow path bypasses the drain restriction.

Abstract: A fuel injector for an internal combustion engine comprising a nozzle body having at least one spray hole. The at least one spray hole has a hole entry on the inside of the nozzle body and a hole exit on the outside of the nozzle body. The spray hole is provided with a hole entry section which, starting from the hole entry, has a flow area which decreases from a relatively larger flow area at the hole entry to a relatively small flow area at the intersection between the end of the hole entry section and the start of a hole exit section. The hole exit section, starting from the intersection with the hole entry section, has a flow area which increases from a relatively small flow area at the intersection with the hole entry section to a relatively larger flow area at the hole exit.

Abstract: A needle for use in a needle valve, such as the needle valve of a fuel injector, comprises a tip section (2), a first guide section (1a) and a second guide section (3). The tip section (2a) has a needle tip. The first guide section (1a) is remote from the needle tip. The second guide section comprises a tube, wherein the first guide section (1a) and the tip section (2a) are comprised in an integrated inner needle component (7) extending through the tube (3). A method of manufacturing such a needle is also described.

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 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 fuel injector for an internal combustion engine comprising a nozzle body having at least one spray hole. The at least one spray hole has a hole entry on the inside of the nozzle body and a hole exit on the outside of the nozzle body. The spray hole is provided with a hole entry section which, starting from the hole entry, has a flow area which decreases from a relatively larger flow area at the hole entry to a relatively small flow area at the intersection between the end of the hole entry section and the start of a hole exit section. The hole exit section, starting from the intersection with the hole entry section, has a flow area which increases from a relatively small flow area at the intersection with the hole entry section to a relatively larger flow area at the hole exit.

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: An injection nozzle for an internal combustion engine, the injection nozzle including an outer valve needle which is engageable with an outer valve seating so as to control injection through a first nozzle outlet, an inner valve needle which is movable within the outer valve needle and engageable with an inner valve seating so as to control injection through a second nozzle outlet, and a coupling arrangement for coupling movement of the outer valve needle to the inner valve needle in circumstances in which the outer valve needle is moved away from the outer valve seating beyond a predetermined amount, thereby to permit fuel injection through both the first and second nozzle outlets.

Abstract: An injection nozzle for an internal combustion engine has a valve member moveable within a bore of a nozzle body, and a seating surface defining a seat cone angle the valve member including a first frustoconical valve region, a second frustoconical valve region, and an annular groove defining, in part, a delivery chamber in communication with at least one nozzle outlet. The annular groove is disposed intermediate the first and second valve regions such that a first seating line is defined at the mutual interface between the first valve region and the annular groove and is engageable with the seating surface to control delivery of fuel from a first supply chamber to the deliver chamber, and a second seating line is defined at the mutual interface between the second valve region and the annular groove and is engageable with the seating surface to control delivery from a second supply chamber to the delivery chamber.

Abstract: An injection nozzle for use in delivering fuel to a combustion space comprises a nozzle body provided with a blind bore within which a valve member is slidable. The valve member comprises a first region of substantially frusto-conical form defining a seating surface which is engageable with a valve seating surface, defined by the blind bore, to control fuel delivery from the injection nozzle, and a second region arranged such that, when the valve member is seated against the valve seating surface, in use, the second region is located downstream of the valve seating surface. The first region subtends a first cone angle which is greater than a second cone angle subtended by the second region.

Abstract: An injection nozzle for use in delivering fuel to a combustion space comprises a nozzle body provided with a blind bore within which a valve member is slidable. The valve member comprises a first region of substantially frusto-conical form defining a seating surface which is engageable with a valve seating surface, defined by the blind bore, to control fuel delivery from the injection nozzle, and a second region arranged such that, when the valve member is seated against the valve seating surface, in use, the second region is located downstream of the valve seating surface. The first region subtends a first cone angle which is greater than a second cone angle subtended by the second region.