Abstract: A fuel injector (1), particularly an injection valve for fuel-injection systems of internal combustion engines, has a piezoelectric or magnetostrictive actuator (16). By way of a valve needle (5), the actuator (16) actuates a valve-closure member (4), which interacts with a valve-seat surface (7) to form a sealing seat. The actuator (16) has a tubular design, and encircles a transmission piston (19) that acts on a hydraulic transmission device (27).

Abstract: The fuel injection valve (16) has an injection valve member (24), by which at least one injection opening (26) is controlled. The motion of the injection valve member (24) is varied by a control valve (18) that has a control valve member (54) by which the pressure in a control pressure chamber (50) is controlled in that the control valve member controls a relief chamber (46) in a closing piston (42) that defines the control pressure chamber (50) and that by means of the pressure prevailing in the control pressure chamber (50) urges the injection valve member (24) in its closing direction. The control valve member (54) is displaceable via a hydraulic boost by a piezoelectric actuator (78), as a result of which the piezoelectric actuator opens or closes the relief chamber (46).

Abstract: A piezoelectric actuated fuel injector is provided for use in conjunction with an internal combustion engine. The fuel injector includes a piezoelectric actuator for actuating an injector valve, and a hydraulic assembly for interfacing between the piezoelectric actuator and the injector valve, where the injector valve axially separates from a discharge outlet in response to longitudinal expansion of the piezoelectric actuator, thereby allowing fuel flow from the fuel injector.

Abstract: A fuel injector pressurizes fuel in a pressurization chamber and ejects the fuel from an orifice. A reverse flow check valve allows fluid communication between the pressurization chamber and the orifice during fuel injection, but blocks fluid communication between the pressurization chamber and the orifice when fuel pressure in the pressurization chamber decreases.

Abstract: A dual solenoid latching actuator is disclosed and provides an electrical circuit that includes at least one current restrictor, which are preferably a first diode and a second diode. The at least one current restrictor is positioned and arranged such that current flowing in a first direction can energize only one of a first solenoid coil and a second solenoid coil and current flowing in a second direction can energize only the other solenoid coil.

Abstract: A control valve configuration is described which is used in a fuel injector for internal combustion engine. The control valve contains a valve body that can be displaced axially in a valve chamber by an actuating device and is formed of two rigidly connected sections. A first section of the valve body forms a seat valve between the valve inlet and valve outlet in a first section of the valve chamber. The seat valve is closed in a rest position of the valve body and is opened in a working position of the valve body. A second section of the valve body and a second section of the valve chamber form a slide valve which, in the rest position of the valve body, produces a fluidic connection between the valve outlet and a return opening and blocks the fluidic connection between the seat valve and the valve outlets and which closes the return opening and then starts to produce a fluidic connection between the seat valve and the valve outlet only after it leaves the rest position.

Abstract: An oil activated fuel injector control valve which substantially eliminates captured air within working fluid of the fuel injector. This eliminates shot by shot variations in the fuel injector as well as increasing the efficiency of the fuel injector. The fuel injector includes a control valve body which has vent holes which prevent air from mixing with the working fluid. In this manner, the working fluid does not have to compress and/or dissolve the air in the working ports prior to acting on the piston and plunger mechanism in an intensifier body of the fuel injector.

Abstract: An oil activated fuel injector which provides a pilot quantity of fuel prior to the main fuel injection event. The oil activated fuel injector includes a throttle which provides fluid communication between the high pressure chamber and a fuel bore which leads to the nozzle of the oil activated fuel injector. The pilot quantity of fuel flows through the throttle and into the fuel bore during a pre stroke of the plunger. The oil activated fuel injector reduces engine emissions and noise, and eliminates the need for additional working fluid to be provided therein in order to provide a pilot quantity of fuel.

Abstract: A hydraulically actuated fuel injection system according to the present invention comprises at least one hydraulically actuated fuel injector that includes an injector body that defines a fuel pressurization chamber. A pumping element having a stepped top is movably mounted in a pumping bore defined by the injector body, wherein the pumping element defines at least one internal passageway. The pumping element is movable a distance between a first position and a second position. A spill passage defined by the injector body is open to the fuel pressurization chamber via the at least one internal passageway over a portion of the distance.

Abstract: A fuel injector for use in an injector arrangement including a fuel pump having a pump chamber and a spill valve arrangement including a spill valve member which is engageable with a valve seating to control communication between the pump chamber and a low pressure drain. The fuel injector further comprises a valve needle which is engageable with a valve needle seating, a control chamber arranged such that the fuel pressure therein urges the valve needle towards its seating, a control valve arrangement, including a control valve member, for controlling the fuel pressure within the chamber, and an actuator arrangement for controlling movement of the spill valve member and the control valve member. The actuator arrangement comprises a double pole actuator having a first armature which is movable with the spill valve member and a single pole actuator having a second armature which is movable with the control valve member.

Abstract: A fuel injection valve for intermittent injection of fuel into the combustion chamber of a diesel or other form of internal combustion engine. The valve achieves a shorter than usual injection valve member, while avoiding valve member oscillation but retaining precise closing by implementing a solenoid controlled piston that controls movement of the valve. The piston in turn is acted upon by fuel system pressure from a high pressure feed line and from a control chamber, alternatively, depending upon the position of an actuating element. The control piston has an annular land that faces the control chamber and the piston is connected to the high pressure feed line through a tight sliding fit in a piston guide bore establishing a leak gap. A relief chamber is formed between the outlet side of the gap and the land. When the injection valve is open, the land reduces fuel flow from the relief chamber into the control chamber.

Abstract: A fuel injector comprising a valve needle slidable within a bore, a surface associated with the valve needle being exposed to the fuel pressure within a control chamber and an electromagnetically actuable control valve controlling communication between the control chamber and a low pressure chamber. The injector also comprises a damping arrangement arranged to damp pressure waves applied to the low pressure chamber.

Abstract: A fuel injector which has a double solenoid three-way or four-way spool valve that controls the flow of a working fluid that is used to move an intensifier piston of the injector.

Abstract: A fuel injector assembly for an internal combustion engine including an injector body in fluid communication with a source of fuel and a nozzle assembly through which fuel is dispersed from the fuel injector assembly during an injection event. A high pressure fuel delivery system provides high pressure fuel to the nozzle assembly. The injector body defines a low pressure fuel spill gallery in which unused fuel is collected from the high pressure fuel delivery system. The high pressure fuel delivery system includes a cylindrical bore, a plunger supported for reciprocation within the cylindrical bore, a pump chamber defined by the plunger and the cylindrical bore, and a high pressure fuel passage extending through the injector body from the pump chamber to the nozzle assembly for dispersing fuel at high pressure from the injector assembly.

Abstract: A fuel injector comprises a valve needle slidable within a bore and engageable with a seating to control the supply of fuel to an outlet opening, an end surface of the valve needle being exposed to the fuel pressure within a control chamber defined, in part, by a piston member moveable under the influence of a piezoelectric actuator. The control chamber may be supplied with fuel under pressure, in use, through a restricted flow path. The piston member may have an effective area exposed to the pressure within the control chamber which is greater than that of the needle.

Abstract: A fuel injection valve for internal combustion engines, having a valve member that is displaceable axially outward counter to a restoring force in a bore of a valve body. On an end toward the combustion chamber, the valve member has a closing head. The closing head protrudes from the bore and forms a valve closing member and on a side toward the valve body has a valve sealing face. The valve closing member cooperates with a valve seat face, disposed on a face end toward the combustion chamber of the valve body. The valve closing member at least one injection opening on the closing head. The injection opening originating at a pressure chamber and outlet opening being covered, in the closing position of the valve member, by the valve body and being uncovered upon an outward-oriented opening stroke. A two-stage hydraulic stroke stop, which limits the opening stroke of the valve member and is embodied as a hydraulic damping chamber with a relief line that can be opened.

Abstract: A fuel injector for use in a diesel engine which is equipped with an engine brake governed by a hydraulic circuit includes an injector body with a hollow interior, a plunger located within the injector body, a moveable coupling positioned within the injector body, a nozzle for the dispensing of fuel, and a variable rate return spring which is positioned between the injector body and the moveable coupling. The variable return spring is designed with a variable pitch between adjacent coils such that the pitch between coils near the end(s) of the spring is reduced over that near the center of the spring. The use of the variable rate spring is intended to address the problem of premature fatigue failures caused by the return spring oscillating at or above its natural frequency. The oscillations are induced due to the exhaust valve opening and closing events and are transmitted directly through the engine brake hydraulic circuit to the injectors by way of the injector push tube.

Abstract: An injector body defines a fuel pressurization chamber, a spill passage, a stop volume and a nozzle outlet. Positioned within the injector body is a plunger which is movable between a retracted position and an advanced position. The plunger opens the spill passage to the fuel pressurization chamber over a portion of the distance between the retracted and advanced positions. The injector body also contains a needle valve member which includes a closing hydraulic surface that is exposed to fluid pressure in the stop volume. The stop volume is pressure coupled to the spill passage.

Abstract: An electronically controlled device, such as a fuel injector, includes a first solenoid and a second solenoid attached to the injector body. An electrical circuit is attached to the injector body, and includes a positive terminal and a negative terminal connected to the first solenoid and the second solenoid. The electrical circuit permits energization of one of the first solenoid and the second solenoid when electrical current flows in either direction between the first terminal and the second terminal. However, the electrical circuit permits energization of the other of the first solenoid and the second solenoid only when current flows in a single direction between the first terminal and the second terminal.

Abstract: A servo-controlled fuel injector is provided which includes a leakage limiting valve device for limiting the quantity of high pressure fuel available for leakage into the combustion chamber in the event the closed nozzle valve element fails to sealingly engage its seat between injection events. The servo-controlled fuel injector includes a control volume positioned adjacent an outer end of the nozzle valve element, a control volume charge circuit for supplying fuel to the control volume, a drain circuit for draining fuel from the control volume to a low pressure drain and an injection control valve positioned along the drain circuit for controlling the flow through the drain circuit so as to cause reciprocal movement of the nozzle valve element. The leakage limiting valve is integrated into the fuel injector body and positioned along a fuel transfer passage to block the flow of high pressure fuel to a nozzle cavity between injection events.

Abstract: A fuel injection valve for internal combustion engines, having a valve member that emerges outward from the valve body. At least two rows of injection ports one above the other are provided on the valve member, in the outward-oriented opening stroke of the valve member the injection parts are uncovered in secession. A two-stage hydraulic stroke stop, which limits the opening stroke travel of the valve member is embodied as a hydraulic damping chamber with openable relief. This relief is effected via at least two polished sections on the valve member which are openable in succession during the opening stroke motion of the valve member. At least one of the polished sections is connected to a low-pressure chamber, via a relief conduit containing a valve.

Abstract: A fuel injection valve, particularly an injection valve for fuel injection equipment of internal combustion engines, having a pump piston that can be activated using a piezoelectric or magnetostrictive actuator for exerting a translatory pump motion. A spray-discharge nozzle with at least one spray-discharge opening is hydraulically connected via a fuel pressure line to the pump piston. The spray-discharge nozzle opens when the fuel pressure produced by the pump piston in the fuel pressure line exceeds a predetermined threshold. In the fuel pressure line, at least one non-return valve is arranged so that it opens in the direction towards the spray-discharge nozzle and closes in the opposite direction.

Abstract: The fuel injection device of this invention utilizes the fuel pressure in the balance chamber for closing the open-close valve to prevent fuel leakage from the open-close portion. When the open-close valve is opened, the valve stem of the open-close valve piercing through the exhaust passage in the control member moves toward the balance chamber. The valve head opens the port of the exhaust passage on the balance chamber side to lower the fuel pressure in the balance chamber, with the result that the needle valve lifts injecting the fuel. When the open-close valve is closed by the return spring, the fuel pressure in the balance chamber acts on the valve head to urge the open-close valve in the valve closing direction, preventing the leakage of fuel through the open-close valve.

Abstract: A hydraulically-actuated fuel injector includes an injector body that defines an upper actuation fluid cavity, a lower actuation fluid cavity, an actuation fluid inlet, a spill passage, a piston bore and a nozzle outlet. A control valve member is positioned in the injector body and moveable between a first position and a second position. An intensifier piston is positioned in the piston bore and moveable between a retracted position and an advanced position. The piston has a primary hydraulic surface exposed to fluid in the upper actuation fluid cavity, and an opposing hydraulic surface exposed to fluid in the lower actuation fluid cavity. The upper actuation fluid cavity is open to the actuation fluid inlet, and the lower actuation fluid cavity is open to the spill passage when the control valve member is in its first position. The spill passage is blocked when the control valve member is in its second position.

Abstract: A fuel injector includes an injector body that defines a nozzle outlet, and a needle control chamber that is in fluid communication with a needle control passage. A needle valve member is positioned in the injector body, and has a closing hydraulic surface exposed to fluid pressure in the needle control chamber. The needle valve member is moveable between a first position in which the nozzle outlet is blocked, and a second position in which the nozzle outlet is open. The needle control passage includes a dual flow rate orifice. Hydraulic fluid is displaced into the needle control chamber through the dual flow rate orifice when the needle valve member moves from its second position toward its first position. Hydraulic fluid is displaced out of the needle control chamber through the dual flow rate orifice when the needle valve member moves from its first position toward its second position. A compression spring is operably positioned to bias the needle valve member toward its first position.

Abstract: A fuel injector that contains no springs and is controlled by a valve assembly that has more than two modes of operation. The fuel injector includes a housing which has a supply port, a drain port and a cylinder passage that is in fluid communication with an intensifier. The intensifier moves between a first position and a second position within a fuel chamber. The fuel chamber is coupled to a fuel port. Movement of the intensifier into the second position pressurizes the fuel within the fuel chamber. The pressurized fuel opens a needle valve so that fuel is ejected through an aperture of the housing. The cylinder passage is coupled to a first fluid control valve and a second fluid control valve. Each control valve can be actuated between a closed position and an open position.

Abstract: A fuel injection device for internal combustion engines in which a fuel injection valve has a tappet which is actuated by an injection valve member and defines a control chamber that is supplied continuously with high fuel pressure via a throttle and can be relieved via a control valve and an outflow conduit. To that end, the control valve has a valve member, which is actuated by a piezoelectric element in such a way that the valve member is moved toward the control chamber when the outflow conduit opens. In the closing position, the valve member is urged in the closing direction by the pressure in the control chamber.

Abstract: A fuel injector includes a center tube which conducts fuel flow. A flat-seat poppet valve surrounds a lower portion of the center tube and controls the application of pressurized fuel to first and second check end passages to assist in check closure.

Abstract: A control valve, preferably for use with a fuel injector, includes a valve body defining an inlet passage separated from an outlet passage by a valve seat. A solenoid is attached to the valve body, and includes a coil and an armature. A portion of the armature is a permanent magnet. The polarity of the permanent magnet is oriented such that the armature is pushed away from the coil when the solenoid is energized. A valve member is positioned in the valve body and attached to the armature. The valve member is moveable between an open position in which the inlet passage is open to the outlet passage, and a closed position in which the inlet passage is closed to the outlet passage.

Abstract: A control valve, preferably for use in a fuel injector, includes a valve body defining an inlet passage separated from an outlet passage by a valve seat. A single pole solenoid is attached to the valve body, and includes a pole piece and an armature. A valve member with a centerline is positioned in the valve body, attached to the armature and moveable between an open position in which the inlet passage is open to the outlet passage, and a closed position in which the inlet passage is closed to the outlet passage. The pole piece is positioned between the valve seat and the armature along the centerline of the valve member.

Abstract: An injector is described which comprises a valve needle engageable with a seating and biased towards the seating by a spring. The spring is located within a spring chamber and engages a moveable stop. The spring chamber communicates through a restricted passage with a low pressure drain. The injector further includes valve means which, when open, permits fuel to escape from the spring chamber at a higher rate.

Abstract: A control valve includes a terminal assembly that has a terminal electrically connected to one of a male electrical connector and female electrical connector. A solenoid assembly includes a metallic solenoid housing defining a solenoid cavity. A solenoid coil and the other of the male electrical connector and the female electrical connector are molded into a plastic solenoid carrier. The plastic solenoid carrier is attached to the metallic solenoid housing and preferably molded into the solenoid cavity. The solenoid assembly is attached to the terminal assembly, and said male electrical connector is mated to the female electrical connector. An armature is positioned between a portion of the terminal assembly and the solenoid coil. A valve member is attached to the armature.

Abstract: An improved cam operated, open nozzle, unit injector is disclosed including an injector body formed by a barrel, spring housing, and nozzle and containing a central bore for receiving a variable length plunger assembly mounted for reciprocal movement within the injector body wherein the variable length plunger is formed by an outer plunger and inner plunger combined with a timing plunger, mounted between the inner and outer plungers to form a collapsible timing chamber into which a variable quantity of fuel may be metered and expelled on a cycle by cycle basis to provide a variable effective length to the plunger assembly to cause controlled variation in injection timing based on variation in the timing fluid supplied to the injector and wherein the timing plunger is provided with a radial flange for engaging a stop formed in the injector barrel to hold the timing plunger in a predetermined precise location during metering of timing fluid into the collapsible timing chamber and to render the injector timing i

Abstract: A fuel injector comprises a barrel, a plunger, and a port. The plunger is disposed in a bore in the barrel such that it intersects the port disposed in the barrel. The plunger has an injection rate shaping device and a cavitation control device disposed therein. The pressure control device is in such a position on the plunger such that subsequent to the rate shaping device passing fluidly communicating with the port, the cavitation control device aligns with the port to control the pressure wave propagated through the port by the termination of rate shaping.

Abstract: A control valve, preferably for use with a fuel injector, includes a valve body defining a solenoid cavity, an inlet passage, an outlet passage and a metering passage extending between the solenoid cavity and the outlet passage. A solenoid is mounted in the solenoid cavity. A valve member has one end attached to the solenoid and is positioned to reciprocate in the valve body between an open position in which the inlet passage is opened to the outlet passage and a closed position in which the inlet passage is closed to the outlet passage. The inlet passage is in fluid communication with the solenoid cavity via the metering passage when the valve member is in its open position. Appropriate sizing of the metering passage can prevent secondary injections by providing adequate pressure relief to the solenoid cavity while also substantially damping any pressure waves that may travel to the solenoid cavity through the metering passage.

Abstract: A pump/injector arrangement comprises a pump including a pump chamber arranged to communicate through a fuel line with an injector. A valve is provided within the injector to control whether or not fuel is able to flow from the fuel line to a control chamber. The control chamber communicates with a low pressure reservoir through a restricted passage. A by-pass is provided to permit fuel to flow from the reservoir by-passing the restricted passage.

Abstract: An electrohydraulically actuatable injection valve includes a control piston which divides an annular conduit from a control chamber disposed between the control piston and an actuator rod. A spring is disposed between the control piston and the actuator rod. The annular conduit also communicates through a control valve with a drain. If the control valve is closed with the injection valve open, the control piston opens a communication between the annular conduit and the control chamber, so that a nozzle needle is pressed onto an associated valve seat and abruptly stops the injection.

Abstract: An injection rate shaping nozzle assembly for a fuel injector is provided which includes a closed nozzle valve element and a rate shaping control device including an injection spill circuit for spilling a portion of the fuel to be injected to produce a predetermined time varying change in the flow rate of fuel injected into a combustion chamber. The spill circuit includes a spill passage integrally formed in the nozzle valve element. The rate shaping control may include a spill valve for controlling the spill flow through the spill circuit to create a low injection flow rate followed by a high injection flow rate. The spill passage may communicate with the injector nozzle cavity between injection events or alternatively may be blocked to prevent spill flow between injection events. The rate shaping control device may include a spill accelerating device in the form of a spill chamber formed in the nozzle valve element for creating a rapid increase in the spill flow rate.

Abstract: An injection rate shaping nozzle assembly for a fuel injector is provided which includes a closed nozzle valve element and a rate shaping control device including an injection spill circuit for spilling a portion of the fuel to be injected to produce a predetermined time varying change in the flow rate of fuel injected into a combustion chamber. The spill circuit includes a spill passage integrally formed in the nozzle valve element. The rate shaping control device may include a spill accelerating chamber in formed in the nozzle valve element for creating a rapid increase in the spill flow rate. A spill circuit purge device is provided to remove fuel from the spill circuit and accelerating chamber between each of the injection events thereby ensuring an unimpeded, effective spill fuel flow during the next spill event.

Abstract: A reciprocating piston/barrel assembly, through which a fluid is capable of flowing, includes a piston having a pressure face separated from a downstream face by a side surface. A barrel has an interior wall surface defining a bore that is sized to slidably receive the piston. The bore is longer than the piston such that the bore includes an upstream volume adjacent the pressure face of the piston and a downstream volume adjacent the downstream face of the piston. The assembly includes some way for producing a pressure differential between the upstream volume and the downstream volume. The side surface and/or interior wall surface include at least one surface irregularity--indentation and/or protrusion--of sufficient size to increase flow resistance. In order to produce the axial force effect of the present invention, the fluid flow between the piston side surface and the barrel's interior wall surface must be faster than the speed of the piston.

Abstract: An injection rate shaping nozzle assembly for a fuel injector is provided which includes a closed nozzle valve element and a rate shaping control device including an injection spill circuit for spilling a portion of the fuel to be injected to produce a predetermined time varying change in the flow rate of fuel injected into a combustion chamber. The spill circuit includes a spill passage integrally formed in the nozzle valve element. The rate shaping control may include a spill valve for controlling the spill flow through the spill circuit to create a low injection flow rate followed by a high injection flow rate. The spill passage may communicate with the injector nozzle cavity between injection events or alternatively may be blocked to prevent spill flow between injection events. The rate shaping control device may include a spill accelerating device in the form of a spill chamber formed in the nozzle valve element for creating a rapid increase in the spill flow rate.

Abstract: A multipiece fuel pump plunger assembly for controlling the fuel injection rate and delivery during the initial injection portion of a fuel injection cycle for an internal combustion engine. The injector includes a two piece plunger assembly including a plunger and a plunger sleeve. The plunger having a small predetermined diameter and being slidably positioned within a plunger sleeve having a diameter greater than the diameter of the plunger. The multipiece plunger is advantageous because it allows for shaping of the rate of fuel injected into the combustion process thereby reducing the excess fuel flow in the early portion of the injection cycle. Elimination of the excess fuel flow results in lower oxides of nitrogen and particulate exhaust emission levels and less engine noise.

Abstract: A fuel injector including a housing having a fuel passage connectable at one end to a source of fuel for the ingress or egress of fuel at a suitable supply pressure, a fuel supply chamber in flow communication with the fuel passage, a pump cylinder in the housing, an externally actuated plunger reciprocable in the pump cylinder at a predetermined clearance therewith and defining at one end thereof a pump chamber open at one end for the discharge of fuel during a pump stroke and for fuel intake during a suction stroke of said plunger. The plunger includes a piston and a push rod concentrically located within the piston along an axis thereof, and fixed thereto to preclude relative axial movement along such axis.

Abstract: A fuel injector comprises a casing, a barrel, a piston, a plunger, a nozzle, a needle check and needle check spring, a rate shaping valve and a rate shaping valve spring. The barrel is disposed in the casing and defines a fuel plunger chamber as well as a rate shaping bore between the fuel plunger chamber and an outside of the barrel with a rate shaping valve seat therein. The plunger is disposed in part in the fuel plunger bore of the barrel. The nozzle is disposed in the casing and defines a tip of the fuel injector and also defines a fuel passage from the fuel plunger chamber to an injection orifice at an end of the tip. The needle check is disposed in the nozzle and operably blocks the orifice in a first position. A needle check spring is disposed in the nozzle between the needle check and a reaction member, biasing the check to the first position. The rate shaping valve is disposed in the rate shaping bore of the barrel.

Abstract: A control valve assembly for a fuel injector includes a valve seat with fluid inlet and fluid outlet and a flat seating surface. A poppet valve has a concave end portion with knife edge for sealingly engaging the flat seating surface on the valve seat. The poppet valve is operated to close by a solenoid coil and is opened and maintained open by a return spring or a permanent magnet. Faster valve closing and faster valve opening is obtained.

Abstract: A unit fuel injector adapted for periodic injection of fuel into a combustion chamber of an engine at variable times from cycle to cycle under the control of the engine lubrication fluid is provided, comprising an injector body containing an injector cavity and a discharge orifice communicating with one end of the injector cavity to discharge fuel into the combustion chamber, a lubrication fluid timing circuit and a fuel metering circuit separate from the lubrication fluid timing circuit. A lubrication fluid link positioned in the lubrication fluid timing circuit within the injector cavity has a variable effective length which is varied by the operation of a control valve positioned within the lubrication timing circuit to vary the timing of injection. The control valve is operated to control the flow of lubrication fluid in the lubrication fluid timing circuit to control both the timing of injection and the metering of fuel on a cycle by cycle basis.

Abstract: A fuel injector for an internal combustion engine includes a main body including a timing bore, a timing plunger disposed in the timing bore, an electronically-operated solenoid valve assembled to the main body, a nozzle having a needle bore and an injection needle disposed in the needle bore which needle is operable under certain conditions to lift so as to initiate fuel injection. Disposed between the main body and the nozzle member is a one-piece adapter which is designed to include an axially-extending metering bore and a needle spring cavity. A metering plunger is disposed within the metering bore and a biasing spring is disposed within the needle spring cavity. At the base of the needle spring cavity is a button which serves as a direct abutment interface between the top of the needle and the bottom of tile biasing spring.

Abstract: A compact closed nozzle assembly for a fuel injector is provided which reduces the total length of the injector, minimizes the trapped volume of fuel and, thus, the response time of the injector and eliminates a high pressure joint in the injector body. The compact closed nozzle assembly of the injector includes a nozzle valve element positioned in an injector cavity adjacent injector orifices and operable to be placed in an open position in which fuel may flow a fuel transfer circuit through the injector orifices into the combustion chamber, and a closed position in which fuel flow through the injector orifice is blocked. A nozzle spring, which is shorter and larger in diameter than conventional nozzle springs, biases the nozzle valve element into the closed position.

Abstract: An improved high pressure fuel injector for internal combustion engines in which problems of hysteresis delays and fuel leakage at the commencement of the metering process can be avoided without affecting the ability to precisely control the fuel supply pressure by the provision of a way for the metering and injection plunger to be acted upon only by the pressure of the incoming fuel supply. An improved metering and injection plunger spring arrangement provides a valving of the drain path that prevents leakage through drain passages and/or about the metering and injection plunger during the fuel metering and injection phases. Also, a double check valve arrangement is incorporated into the plunger seat disc to minimize the possibility of back-flow leakage of fuel during injection of the fuel from the metering and injection chamber.

Abstract: The present invention is an improvement to fuel pumps/injectors in which fuel is pressurized in a fuel chamber to a pressure great enough to open an injection valve allowing the fuel to be ejected under pressure into the combustion cylinder of an engine. More particularly, the present invention is a device positioned in the fuel path which typically runs from the plunger chamber to the injection valve. For injection, the device is positioned to allow fuel to flow from the plunger to the injection valve. To end injection, the device closes off the flow of fuel thereby separating the fuel path into two portions. The drainage of fuel from the first portion is restricted by an orifice, thereby maintaining pressure in the first portion which prevents the fuel pressurizing mechanism components from separating. In the second portion, pressure is vented back to the fuel supply manifold thereby allowing the injection valve to quickly close, ending injection.