Abstract: A fuel injector and a method of assembly includes a determination of various flow areas through clearances or openings formed in various components of the injector. With the various flow areas determined, the various components can be classified according to their flow areas such that sets of components can be selected having desirable flow area characteristics for assembly of the fuel injector.

Abstract: A valve chamber is defined in a valve body of the regulating check valve. A first communicating hole and a second communicating hole communicate the valve chamber with a first flow passage and with a the second flow passage, respectively. A valve element is slidably installed in the valve chamber to seat on or lift away from a valve seat to close or open the first communicating hole. A pressure in the first flow passage urges the valve element away from the valve seat, and a pressure in the second flow passage urges the valve element toward the valve seat. The spring is interposed between the valve element and the valve body to urge the valve element away from the valve seat.

Abstract: A fuel injector includes a fuel injector body defining a fuel inlet and at least one fuel outlet, a valve having a first valve state and a second valve state and an actuator for the valve. The fuel injector includes a biasing spring including a cylindrical rolled sheet having a first spring end, a second spring end and defining a longitudinal center axis. The cylindrical rolled sheet is configured to change in length to bias the actuator toward the first actuator position and includes a helical seam located between the first spring end and a second spring end which has a shape adapted to reduce non-uniformity in a spring constant via distributing stiffness about the longitudinal center axis.

Abstract: The invention relates to an injector for injecting fuel into a combustion chamber of an internal combustion engine. The injector is actuated by an actuator and is connected to a fuel supply line via which fuel is supplied under system pressure. At least one injection opening can be opened or closed off by an injection valve member, which is activated by a control piston via a control chamber to which the control piston and a piston section of the injection valve member are exposed with respective pressure faces. The control piston is a valve piston of a control valve. The pressure face of the control piston and the pressure face of the piston section of the injection valve member are exposed to the control chamber at the same side. The control piston and the piston section of the injection valve member also enclose a further control chamber which is connected to a fuel return line when the control valve is open and to the fuel supply line when the control valve is closed.

Abstract: A fuel injector having a body with a bore, which defines a fuel manifold. The injector also has a variable-area injector arrangement having a pintle with a conical head and a pintle spring connected to the body. The pintle spring urges a tip of the pintle to seal against an exit orifice of the body, such that application of pressurized fuel within the body causes the pintle to move. Above some threshold pressure, the pressurized fuel causes the conical head to move out of contact with the exit orifice of the body. This, in turn, provides a corresponding variable area for passage of the pressurized fuel through the exit orifice about the conical head of the pintle. The injector further includes a swirler configured to create a swirling action in the flow of pressurized fuel through the fuel manifold, wherein the manifold is upstream of the exit orifice.

Abstract: An injection valve has an injector housing (1) and an actuator and also a nozzle assembly. The nozzle assembly has a nozzle body (6) with a recess (8) into which a nozzle needle (10) is introduced and at one axial end of which an injection nozzle (12) is embodied. The recess (8) has, axially adjacent to the injection nozzle (12), a first guide region (14) for the nozzle needle (10). The recess (8) also has at least one cross-sectional extension which extends toward the other axial end. The recess (8) is embodied for the purpose of delivering fluid to the injection nozzle (12). A guide bushing (20) is introduced into the recess (8) in a subsection of the cross-sectional extension, the guide bushing (20) forming a second guide region (22) for the nozzle needle (10) and being embodied for conducting fuel radially outside of the second guide region (22).

Abstract: A fuel injector for use in an internal combustion engine, comprising a nozzle body being provided with a nozzle bore and at least one set of one or more outlets for fluid, an outer valve member received within the nozzle bore and being engageable with a first seating region of the nozzle body to control the flow of a first fluid from a first delivery chamber, the outer valve member being provided with an outer valve bore, and an inner valve member received within the outer valve bore and being engageable with a second seating region of the nozzle body to control the flow of a second fluid from a second delivery chamber. In various embodiments, the fuel injector can be arranged to allow the first and second fluids to be injected separately and/or together. In one embodiment, the first and second fluids can be mixed within the injector before injection.

Abstract: A pressurizing piston has a head section, which contacts an axial end face of a piezoelectric actuator to receive displacement of the actuator, and a piston wall section, which is formed in a cylindrical shape and can move in an axial direction in response to the movement of the head section. The head section and the piston wall section are combined such that relative displacement therebetween is possible in a radial direction. An outer sleeve slidably holding an outer periphery of the piston wall section restricts radial movement of the head section. When an expansion-contraction direction of the actuator inclines with respect to the axial direction, inclination of the piston wall section is inhibited by a radial deviation caused between the head section and the piston wall section. Thus, pinching of the piston wall section to the outer sleeve is inhibited.

Abstract: A fuel injection valve comprises a valve return spring as a coil spring that applies a spring force to a movable valve element toward a valve seat and an adjuster that is used for adjusting a spring force by adjusting the amount of spring compression. The injection valve is provided with parts supporting respectively both ends of the spring in the axial direction, and the parts rotatable in the circumferential direction of the spring.

Abstract: A fuel injection apparatus with a piston device that includes a channel and a piston in the channel. A position sensor is used to detect the piston movement inside the channel when the fuel injection apparatus is energized and de-energized, and the sensing value is used for controlling fuel injection rate in real-time and diagnosing failures in the apparatus. With an actuator installed, the piston can also be used for independently modulating fuel pressure during fuel injection. Thereby the shape of fuel injection pulses is controlled. The fuel injection apparatus has three injection states, and flexible fuel injection timing and multi-pulse injection are allowed. Furthermore, in all injection states, fuel supply has no direct contact to combustion chamber. As a result, when a malfunction sticks the apparatus open, no fuel is supplied. This feature provides a safety nature to the fuel injection apparatus.

Abstract: This injector with two valves (7, 10) which open at different fuel pressures so as to establish a primary flow regime and then a secondary flow regime is characterized in that the primary regime is enriched with fuel via an orifice (21) which adds a branch to the primary flow path of the fuel, but which is closed when the secondary valve is displaced so as to prevent enrichment of the fuel in the secondary regime. This invention applies in particular to certain aircraft engines.

Abstract: The housing body (14) of the fuel injection valve comprises a recess (108), the end region of said recess having a conical tapering (110) on the bottom side thereof. The supporting body (48) engages in said conical tapering (110) with a projection (116) also comprising a conical end region (118). The closing spring (40) is supported on the needle-shaped injection valve member (34) on one side, and on the guiding sleeve (38) on the other side. The guiding sleeve (38) is supported on the supporting body (48) with the front side (461) thereof, whereby the supporting body is held against the tapering (110) in a sealing manner, under the force exerted by the closing spring (40).

Abstract: A fuel injector having an injector body and a fuel inlet communicates with a high-pressure fuel source outside the injector body and including an actuator received in a hollow chamber from which a high-pressure inlet extends to an injection valve member. Depending on the pressure in the first hydraulic chamber, fuel is injected into a combustion chamber of an internal combustion engine when the injection valve member lifts from a seat. The actuator acts directly upon a stepped piston which defines the first hydraulic chamber and actuates a control piston. The injection valve member is guided in the control piston.

Abstract: An electronic unit injector comprising a spray tip including a valve seat, a needle valve arranged to close on the seat to prevent discharge of fuel from the spray tip or to open off the seat to dispense fuel from the spray tip, a spring biasing the needle valve to a closed position, a spring seat between the spring and the needle valve, the needle valve overcoming the biasing force when the pressure reaches a predetermined level, the spring and seat being disposed in a cage having port areas circumferentially arranged about said spring and spring seat to supply low pressure fuel to the area occupied by said spring and spring seat to reduce the risk of cavitation in said spring cage.

Abstract: An injector used for an internal combustion engine includes a valve needle which closes a fuel passage by contacting a valve seat and opens the fuel passage by separating from the valve seat. A coil and a magnetic core are provided to drive the valve needle, and an anchor is held in a relatively displaceable state with respect to the valve needle. A first biasing device biases the valve needle in a direction opposite to a direction of a drive force, and a second biasing device biases the anchor in the direction of the drive force with a set load smaller than that of the first biasing device. A restricting feature restricts relative displacement of the anchor with respect to the valve needle in the direction of the drive force.

Abstract: In an electromagnetic fuel injection valve, a valve housing is formed by sequentially connecting a valve seat member, a magnetic cylinder, a nonmagnetic collar, and a stationary core. A coil housing is fittingly fixed to an outer periphery of the magnetic cylinder, and houses a coil assembly provided in an outer periphery of the stationary core. The coil housing includes a shell part surrounding the coil housing, an annular bent part bent radially inward from a front end of the shell part, and a cylindrical boss part projecting forward from a front end of the annular bent part. An inner peripheral surface of the annular bent part and an inner peripheral surface of at least a rear half part of the boss part are shrinkage-fitted to an outer peripheral surface of the magnetic cylinder.

Abstract: A fuel injection valve includes a housing having a wall surface on an opposite side of the nozzle hole. A fuel passage opens in the wall surface, and communicates with a nozzle hole through a nozzle cavity. The nozzle cavity accommodates a valve element. A cylinder is substantially in contact with the wall surface at one end, and slidably accommodating one end of the valve element. The cylinder partitions the nozzle cavity substantially into a fuel accumulator chamber and a pressure control chamber. The fuel accumulator chamber accumulates fuel supplied from the fuel passage. The pressure control chamber accumulates fuel for manipulating the valve element. The cylinder has an outer wall defining a deflecting surface for radially outwardly deflecting fuel flowing from the fuel passage.

Abstract: An electrically controlled fuel injector includes an armature that is movable between a first armature position and a second armature position inside an armature cavity containing fuel. By reducing the size of the armature cavity to a squish film drag gap, the armature experiences a squish film drag phenomenon when the armature moves from the first armature position to the second armature position reducing the armature travel speed but also reducing the settling time of the armature after an injection event. By reducing the armature travel speed; the armature experiences a reduction in magnitude of armature bounce allowing the armature to settle down quicker and produce minimum controllable injection events with shorter dwell times than predecessor fuel injectors, especially for close coupled post injection events.

Abstract: An injection nozzle for an internal combustion engine comprising a nozzle body defining a seating surface and having at least one first nozzle outlet and a valve member received within the nozzle body and engageable with an external seating defined by the seating surface so as to control fuel injection through the at least one first nozzle outlet. The valve member is provided with a bore having an internal bore surface and an insert is received within the bore. The insert includes a part-spherical head which spans an internal diameter of the bore so as to maintain contact with an internal surface of the bore as the valve member moves, in use, so as to guide movement of the valve member. The part-spherical head also includes a surface which defines an internal seating for the valve member.

Abstract: A fuel injector (1), in particular a pump-nozzle injector for a diesel engine has an injector body (50), which is held in place with a nozzle body (40) and/or a lower body (60) by a clamping nut (10, 30). The fuel supply conduit of the injector body (50) is provided with a fuel filter (20), which is offset in the longitudinal direction of the fuel injector (1) in relation to the clamping nut (10, 30) and is configured independently of said clamping nut (10, 30) on the fuel injector (1).

Abstract: The occurrence of leaks can be reduced by a fuel injection device (10) for injecting fuel into the combustion chamber of an internal combustion engine, wherein the fuel injection device (10) has an injection valve element (14) with a first section (26) on which a guide bearing element (20) is arranged, with provision being made for a first pressure chamber (22) in an area around the guide bearing element (20).

Abstract: A fuel injection system having one high-pressure fuel pump and one fuel injection valve, communicating with the high-pressure fuel pump, for each cylinder of an internal combustion engine. A pump work chamber is defined by a pump piston, and the fuel injection valve has an injection valve member by which at least one injection opening is controlled. An electrically actuated control valve controls a communication of the pump work chamber with a relief region and a movable control piston acts at least indirectly in the closing direction on the injection valve member, and the control piston, on its side remote from the at least one injection valve member, is acted upon at least indirectly by the pressure prevailing in the pump work chamber. The control piston, with its side toward the injection valve member, defines a control chamber.

Abstract: An injector has an inner sleeve between a needle pressure receiving face of a needle and a rear end face of a valve body. The inner sleeve is slidably fitted to an outer periphery of a middle shaft section of the needle. The inner sleeve receives a reaction force of a spring located between the inner sleeve and a pressurizing piston, so an axial tip end (edge section) of the inner sleeve is pressed against the rear end face to achieve close contact therebetween. Thus, a volume of a pressure chamber can be reduced, so a valve opening force for lifting the needle can be acquired efficiently. Accordingly, injection of a large flow rate can be performed by increasing a lift amount of the needle and also quick lifting of the needle can be performed.

Abstract: An injector includes a nozzle hole, a needle, an actuator, a piston that is displaced in an axial direction according to extension or contraction of the actuator, an outer sleeve holding the piston slidably on its outer circumferential side and defining a pressure chamber expanded or shrunk according to displacement of the piston. When fuel pressure in the pressure chamber is increased upon extension of the actuator, the needle opens the nozzle hole. The injector further includes an inner sleeve slidably fitted around the needle and received in the pressure chamber, an urging device for urging the inner sleeve in the axial direction and for increasing or decreasing its urging force according to displacement of the piston, an engagement surface, and a fuel chamber. A gap between the fuel chamber and the pressure chamber is closed or opened when the inner sleeve annularly engages or disengages from the surface, respectively.

Abstract: A fuel injection device has a nozzle body formed with an injection hole for injecting fuel and a nozzle needle reciprocating in the nozzle body to open and to close the injection hole. The nozzle needle has a sliding portion capable of moving in the nozzle body in a sliding manner, an insertion portion, of which diameter is smaller than that of the sliding portion, and a pressure receiving portion connecting the sliding portion with the insertion portion. The nozzle body has a guide portion for slidably holding the sliding portion and a fuel sump chamber formed on the injection hole side of the guide portion. The insertion portion is inserted through the fuel sump chamber. A clearance decreasing toward the fuel sump chamber is provided between the guide portion and the sliding portion.

Abstract: A fuel injector assembly for an emissions-based EMD 710 locomotive dieselengine. The fuel injector assembly includes a needle slidably positioned within a bore of a valve body of the injector assembly, where fuel pressure introduced into a bore chamber causes the needle to open a spray tip. A spring mounted within the bore forces the needle to close the spray tip when the fuel is not being applied. The spring is a dead coil spring including inactive coils where at least portions of the coils at both ends of the spring are in intimate contact with each other so as to reduce spring wear during operation of the assembly. Because the dead coil spring has reduced wear, the VOP set point of the fuel injector assembly can be reduced, which reduces NOx emissions.

Abstract: The movement of an injection valve member, which can be longitudinally displaced and guided in a housing and which is used to close and release injection openings, is controlled of a hydraulic control device which comprises a control body which is maintained in a central bore on the periphery thereof and which is provided with a control duct which is connected to a control area on a lower front-surface side of the control body and which is sealed on another upper front-surface side of the control body and which can be connected to a low pressure area by a pilot valve.

Abstract: A fluid injector has a housing, an actuator unit and a valve body (2). The valve body (2) has a needle (22), which closes or opens a nozzle (213) depending on its position and comprises a guided zone (221). It further has a first part (21), which is arranged in a fixed position relative to the nozzle (213) and has a guided zone (215). It further has a second part (24), which has a first guide zone (242), that guides the guided zone (221) of the needle (22), and which has a second guide zone (243), that guides the guided zone (215) of the first part (21), with the second guide zone (242) having a greater diameter than the first guide zone (242).

Abstract: An injection nozzle for use in delivering fuel to an internal combustion engine includes an outer valve (24) which is engageable with an outer valve seat (38) so as to control fuel delivery into the engine through a first nozzle outlet (26) and an inner valve (32) which is slidable within a bore (30; 130) provided in the outer valve (24) and engageable with an inner valve seat (40) so as to control fuel delivery into the engine through a second nozzle outlet (28).

Abstract: A fuel injection device for an internal combustion engine includes a housing and a valve element arranged within the housing. The valve element interacts with a valve seat lying in the region of a fuel outlet opening. It is proposed that at least one control piston and a nozzle needle of the valve element be coupled to one another via a hydraulic coupler. The hydraulic coupler has a coupling space and a non-return valve connected to the coupling space and which opens away therefrom.

Abstract: A fuel injector having an injection nozzle comprising a nozzle body being provided with a nozzle bore, an outer valve received within the nozzle bore and being engageable with a first seating to control fuel delivery through a first set of one or more nozzle outlets. The outer valve is provided with an outer valve bore within which an inner valve is received the inner valve being engageable with a second seating to control fuel delivery through a second set of one or more nozzle outlets. The fuel injector further includes an injection control chamber for fuel and pressure control means for controlling the pressure of fuel within the injection control chamber.

Abstract: A fuel injector is described that includes a polymeric housing, pole piece, filter assembly, coil assembly, spring member, armature assembly and metering assembly. The housing has a passageway extending between an inlet opening and an outlet opening along a longitudinal axis. The pole piece is disposed in the passageway and has a through opening. The filter assembly has a portion disposed in the through opening of the pole piece. The coil assembly is disposed in the housing to surround the pole piece. The spring member is disposed partly in the pole piece and includes a spring portion contiguous with the portion of the filter assembly. The armature assembly is disposed in the passageway in a first position confronting the end face of the pole piece and in a second position contiguous to an end face of the pole piece. The metering assembly is disposed proximate the outlet opening and includes a seat and a polymeric support member secured to the polymeric housing.

Abstract: The fuel injector comprises a hollow casing, fixed on which is a nozzle having a nebulizer for the fuel under pressure, a needle axially mobile for opening and closing the nebulizer by means of a first end thereof, and a control rod, substantially coaxial with the needle and in direct engagement therewith. The needle is normally pushed into a closing position of the nozzle by the fuel under pressure acting on the rod, aided by a compression spring, which acts on the needle through a sleeve that is in axial engagement with a portion of the rod. The sleeve further comprises a surface designed to engage at the front and directly one end of the needle. The spring engages another surface of the sleeve so as to transmit its action directly onto the needle.

Abstract: The invention relates to a fuel injection device with a multi-part injector body containing a pressure booster that can be actuated by means of a differential pressure chamber, and includes a pressure booster piston that seals a working chamber off from the differential pressure chamber. An on-off valve disposed above the injector body can actuate the fuel injection device. A pressure change in the differential pressure chamber occurs via a central control line that extends through the pressure booster piston of the pressure booster.

Abstract: A fuel injector for fuel-injection systems of internal combustion engines includes a valve-closure element cooperating with a valve seat, and a restoring spring which is situated in a spring pocket opening and acts upon the valve-closure element by a restoring force in the direction of the valve seat. The restoring spring has at least one holding coil in a region of the inflow side, whose area of cross section is positioned perpendicular to an area of cross section of the restoring spring.

Abstract: A fuel injector is provided having a needle valve element and a nozzle member with a central bore configured to slidingly receive the needle valve element. The fuel injector also has a spring configured to bias the needle valve element toward a closed position. In addition, the fuel injection assembly has a guide element configured to reduce a lateral movement of the needle valve element. The fuel injection assembly further has a fluid flow restricting device configured to restrict the flow of a fluid through the needle valve element and create a fluid pressure differential between the fluid upstream and downstream of the fluid flow restricting device.

Abstract: A fuel injector for an internal combustion engine has a nozzle needle that opens or closes at least one injection opening. At an end oriented away from the at least one injection opening, the nozzle needle has a step-shaped widening, which forms an end surface oriented toward the at least one injection opening. The end surface, an end surface of a first booster, and an end surface of a second booster delimit one side of a control chamber; an actuator moves the first booster and the second booster into or out of the control chamber.

Abstract: An electrically operated injector (1) for feeding a gaseous fuel to a cylinder of an internal combustion engine, in particular for a motor vehicle, includes an electromagnetic actuator (2) acting on a mechanical interceptor member (3) arranged to free or intercept a passage (4) for the fuel from a feed conduit (61) to a delivery conduit (5) connected to an outlet (6), between the delivery conduit (5) and the interceptor member (3) there being positioned a seal element (40). This latter is carried by the interceptor member (3) and has a shape tapering towards the delivery conduit (5) in order to effectively intercept the fuel gas passage (4) and minimize the area of impact with an annular end portion (43) of the delivery conduit (5).

Abstract: A valve (10) is described for use in oil injection of an oil mist (8) for lubricating/flushing cylinders in large engines and arranged with mounting means (14) for fastening in a cylinder wall (2) with a valve stem (12, 13) extending through the cylinder wall and with a nozzle outlet (6) at the inner end of the valve stem. A valve is made, the spray direction of which may be adjusted after mounting. Therefore, the valve is peculiar in that the nozzle outlet (6) is disposed in the inner valve stem part (13) which is rotatable relative to an outer valve stem part (12) . The outer valve stem part (12) is fastened to or made as an integral part of the mounting means (14).

Abstract: A fuel injection system for internal combustion engines, having a fuel injection nozzle supplied with fuel by a high-pressure fuel source, which fuel injection nozzle has a movable nozzle piston for opening and closing injection openings, an injection nozzle high-pressure chamber, and an injection nozzle control chamber. A pressure boosting device connected between the fuel injection nozzle and the high-pressure fuel source has a movable piston, a work chamber, and a high-pressure chamber, in which a filling connection which is open for filling the high-pressure chamber when the fuel injection nozzle is closed and is itself closed when the fuel injection nozzle is open.

Abstract: A fuel injector provided with: an injection valve comprising an injection nozzle; a mobile needle for regulating the fuel flow through the injection valve and ending with a shutting head, which engages a valve seat of the injection valve, is arranged externally with respect to injection valve and presents a predetermined sealing diameter; an actuator for displacing the needle between a closing position and an opening position of the injection valve; a closing spring which tends to maintain the needle in the closing position of the injection valve pushing the shutting head against the valve seat itself in a sense contrary to the feeding sense of the fuel; and a supporting body having a tubular shape and presenting a feeding channel within which a needle is arranged; the needle, at an opposite end of the shutting head, is coupled to a balancing channel, which is at ambient pressure.

Abstract: A fuel injector apparatus and method is provided for use in a fuel injection system of an internal combustion engine that includes a body, a valve seat, closure member, and an orifice plate. The valve seat comprises the intersection of two angled surfaces with a radius before assembly of the fuel injector. During assembly of the fuel injector, a member presses against the radius edge of the sealing surface of the valve seat to create an oblique third sealing surface or sealing band that is coined into the valve seat. The sealing band provides an improved seal between the valve closure member and the valve seat which operates to prevent leakages of fuel in the fuel injector.

Abstract: A fluid injector has a housing, a valve body and an actuator unit inserted into the housing. The valve body has a cartridge with a recess that takes in a needle. The valve body further has a hollow body arranged in a fixed position to the needle and forming a first spring rest. The valve body further has a valve cap, which takes in the cartridge and forms a second spring rest. A return spring rests on the first spring rest and on the second spring rest. The valve cap, the housing and the cartridge are formed such, that before the valve cap and the housing and the valve cap and cartridge are permanently fixed to each other the valve cap is moveable relative to the housing and the cartridge while the housing and the cartridge stay in a fixed position relative to each other.

Abstract: Fuel injector assemblies with frictionally damped fuel supply members, including fuel feed strips. More particularly, the invention provides friction dampers and/or assemblies that frictionally damp movement of fuel supply members in at least one direction as a function of frequency. Accordingly, low frequency vibration can be undamped, while vibration above a prescribed frequency can be damped. Some of the embodiments provide a friction damper that is easily serviceable, and can be installed after final assembly of a fuel injector. Aspects of the invention are applicable to other components of fuel injectors and gas turbine engines in addition to fuel supply members.

Abstract: A fuel injector provided with an injection jet, an injection valve, the latter having a mobile plunger for regulating the flow of fuel through the injection jet, and an electromagnetic actuator, which is capable of displacing the plunger between a closed position and an open position of the injection valve and has a pair of electromagnets, each having a coil, a fixed magnetic armature, and a mobile armature; on the outer surface of a tubular supporting body of the injector, there are produced two annular slots, in each of which there is wound a corresponding coil of an electromagnet.

Abstract: A fuel injector comprises an injector body having a tip portion defining a spray aperture; a pintle extending within the tip portion for axial movement between an extended position and a retracted position, the pintle having a head portion engageable with the spray aperture to close the spray aperture when the pintle is in its retracted position; biasing means being provided for biasing the pintle towards its retracted position; and solenoid means for selectively moving the pintle into said extended position; said solenoid means comprising an electromagnetic coil and a moveable armature capable of being acted upon by the coil to urge the pintle towards its extended position; wherein the pintle and armature are separable from one another whereby the armature can decouple from the pintle when the pintle moves from its extended position to its retracted position.

Abstract: A fuel injector having a stroke reversal with a two-stage pressure booster. If the piezoelectric actuator expands, then via a control piston, a pressure p2 is briefly elevated in a second control chamber and a booster piston is displaced counter to a closing direction, as a result of which the pressure p2 of the hydraulic fluid in the second control chamber rises again. The booster piston carries an injection valve member along with it produces a first opening motion of the injection valve member. By the motion of the control piston in the closing direction, a pressure p1 in a first control chamber is briefly reduced. The first control chamber is in communication, via a pressure equalization conduit, with a differential pressure chamber of the injection valve member and the pressure p3 in the differential pressure chamber also drops, producing a further, hydraulic force further raising the injection valve member.

Abstract: A fuel injection device has a nozzle body formed with an injection hole for injecting fuel and a nozzle needle reciprocating in the nozzle body to open and to close the injection hole. The nozzle needle has a sliding portion capable of moving in the nozzle body in a sliding manner, an insertion portion, of which diameter is smaller than that of the sliding portion, and a pressure receiving portion connecting the sliding portion with the insertion portion. The nozzle body has a guide portion for slidably holding the sliding portion and a fuel sump chamber formed on the injection hole side of the guide portion. The insertion portion is inserted through the fuel sump chamber. A clearance decreasing toward the fuel sump chamber is provided between the guide portion and the sliding portion.

Abstract: A fluid injection device including a protruding needle. One end of the needle forms a valve and can be moved between a closed position, in which the valve seals the fluid-release opening, and an open position, in which the valve is positioned at a controlled distance from the opening. Movement of the valve between the closed position and the open position is produced by the controlled intrinsic extension of the protruding needle.

Abstract: The invention provides an injection nozzle for an internal combustion engine, the injection nozzle (2) including an outer valve member (8) received within a bore (6) provided in a nozzle body (4) and being engageable with a first seating region (20) to control fuel flow from a first delivery chamber (32) to a first nozzle outlet (22), an inner valve member (44) slidable within an outer valve bore (34) provided in the outer valve member (8) and being engageable with a second seating region (46) to control fuel flow from a second delivery chamber (62) to a second nozzle outlet (48), a lifting arrangement (80) associated with the outer valve member (8) such that movement of the outer valve member (8) is transmitted to the inner valve member (44) when the outer valve member (8) is moved through a distance greater than a predetermined distance (L), and a control chamber (7) arranged to receive pressurised fuel, in use.