Abstract: A hydraulically-actuated unit fuel injector of the intensifier type is provided with two independently operable active control valves. A selectively actuable fuel pressure control valve is disposed on the hydraulic actuation fluid side to control the fuel pressure actuation process and provide a window of injection opportunity wherein the fuel pressure is maintained at high pressure. A selectively actuable timing control valve is disposed on the high pressure fuel side to provide precise control of injection timing events and duration, such as start of injection, end of injection, timing of interruption and duration of interruption, which all may occur during a single injection event within the window of opportunity. The timing control valve may take various forms including piezo controlled direct needle actuation valves and common rail injector needle control valves.

Abstract: A fuel injection device (1) for internal combustion engines, with an injection nozzle that can be supplied with fuel from a high-pressure fuel source (8) and with an actuating element (9) that opens and closes the injection nozzle as a function of the pressure in control chamber (6) is proposed. A high-pressure line (7) discharges into the control chamber (6), and an outflow conduit (10) leads away from the control chamber (6) and can be blocked by a closing element (13) of a valve member (3). A high-pressure delivery system (19, 20, 21, 22) that leads into a nozzle chamber can be blocked by a first valve seat (4) of the valve member (3), and the valve member (3) is movable by a defined stroke length by means of an actuator (2). As a function of this stroke length, the closing element (13) is movable between a closing position and an opening position, the latter relieving the control chamber (6) and allowing an injection (Drawing).

Abstract: The fuel injection valve is in particular a component of a reservoir fuel injection system and has a valve body and an electric control valve that controls the pressure which prevails in a control pressure chamber and acts at least indirectly on an injection valve member in its closing direction, wherein the control pressure chamber is connected to a high-pressure fuel source and can be connected by the control valve to a discharge chamber in order to open at least one injection opening. The control pressure chamber is embodied in a sleeve-shaped section of an insert piece inserted into the valve body and is connected to an inlet bore in the valve body by means of an annular chamber encompassing the section and a connecting bore provided in the valve body. The connecting bore intersects the inlet bore at an obtuse angle (&agr;) in a region that is offset from the annular chamber in the direction of the longitudinal axis of the valve body.

Abstract: A hydraulically-actuated unit fuel injector of the intensifier type is provided with two independently operable active control valves. A selectively actuable fuel pressure control valve is disposed on the hydraulic actuation fluid side to control the fuel pressure actuation process and provide a window of injection opportunity wherein the fuel pressure is maintained at high pressure. A selectively actuable timing control valve is disposed on the high pressure fuel side to provide precise control of injection timing events and duration, such as start of injection, end of injection, timing of interruption and duration of interruption, which all may occur during a single injection event within the window of opportunity. The timing control valve may take various forms including piezo controlled direct needle actuation valves and common rail injector needle control valves.

Abstract: A fuel injector including a control valve arrangement for controlling fuel pressure within a control chamber comprises a control valve member which is movable between a first position in which the control chamber communicates with a source of high pressure fuel and a second position in which the control chamber communicates with a low pressure fuel drain and communication between the control chamber and the source of high pressure fuel is broken. The control valve arrangement includes a restricted flow path for restricting the rate of flow of fuel from the source of high pressure fuel to the control chamber when the control valve member is moved towards its first position.

Abstract: A fuel injector comprising a valve needle slidable within a first bore, a surface associated with the valve needle being exposed to the fuel pressure within a first control chamber and movement of the valve needle away from the valve needle seating being limited by a moveable stop member. The stop member has a surface exposed to fuel pressure within a second control chamber. The fuel injector also includes a control valve arrangement for controlling the fuel pressure within the first and second control chambers to control movement of the valve needle and the stop member. The invention also relates to a fuel injector in which the control valve arrangement is arranged to permit the rate of valve needle movement away from the valve needle seating to be varied, in use.

Abstract: In a hydraulic stroke step-up system, in particular for an injection nozzle of a fuel injection system, having a base body (10), an inlet piston (24), a coupling chamber (38) which is filled with a hydraulic fluid, and an outlet piston (14), reliable ventilation of the coupling chamber on the one hand and a loss-free conversion of a motion of the inlet piston into a motion of the outlet piston on the other are to be assured. To this end, an intermediate piston (20) is provided, which is displaceable between a position of repose, in which the coupling chamber is closed from the outside by a ventilation opening (40), and a working position in which the ventilation opening and thus the coupling chamber are closed.

Abstract: In an injection nozzle (10) for a fuel injection system, having a pressure chamber (26) which is provided with a fluid inlet (24) and a fluid outlet (30), having a valve seat (32) around the fluid outlet, having a valve element (34) which can contact the valve seat, so that the fluid outlet is closed, and having a piezoelectric actuator (40), which is provided with an actuation extension (42) that can engage the valve element, a temperature compensation is to be attained at little effort. To that end, it is provided that a displaceable wall part (28) is provided, on which the valve seat is embodied and which defines the pressure chamber on the side of the valve seat, and that a temperature compensation element (44) is provided, which cooperates with the displaceable wall part and displaces it in accordance with a temperature-dictated change in length of the piezoelectric actuator.

Abstract: A fuel injector comprising a nozzle body provided with first and second outlet openings for fuel, a valve needle slidable within a valve needle bore defined in the nozzle body, the valve needle bore being shaped to define a seating with which the valve needle is engageable to control fuel flow to a chamber, the valve needle being provided with a flow passage communicating with the chamber, movement of the valve needle away from the seating into a first fuel injecting position permitting fuel delivery through the first outlet opening and whereby movement of the valve needle away from the seating into a second fuel injecting position causes fuel in the chamber to flow through the flow passage for delivery through the second outlet opening. The nozzle body may include an upper nozzle body part provided with a through bore and a lower nozzle body part provided with a blind bore, the lower nozzle body part being received in the through bore to close an open end thereof.

Abstract: A fuel injector arrangement comprising a nozzle provided with a first bore within which a valve needle is slidable, the needle being engageable with a seating to control the flow of fuel from a delivery chamber to an outlet opening. The arrangement includes a surface associated with the needle which is exposed to the fuel pressure within a control chamber, and a fuel pressure actuable control valve controlling the supply of fuel to the delivery chamber.

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: The invention relates to a device for injecting fuel, having an injector (1) that contains a pressure chamber (13). From the pressure chamber (13), a high-pressure line (5) extends through the injector housing (2), in which a nozzle (3) is disposed that can be closed by means of a nozzle needle (4); the nozzle needle (4) is acted upon by means of a force storing means (7). Via an actuator element (11), control valves (8, 10) that are adjustable and triggerable independently of one another are provided, which communicate with one another via a coupling chamber and by way of which the injection pressure course (24) can be controlled.

Abstract: A fuel injector system (10) includes a piezoelectric sensor (52) mounted along a spool axis (18) of the injector body (12). The piezoelectric sensor (52) is mounted within a spool valve stop (41). As the spool valve (16) reaches the stop (41), the piezoelectric sensor (52) identifies the force exerted thereupon and transmits the generated signal to the controller (44). Through communication with piezoelectric sensor (52) the controller determines when the spool valve (16) has reached a predetermined position.

Abstract: An injection device for a fuel reservoir injection system is proposed, having an injection nozzle (16), which protrudes into a combustion chamber and can be supplied with fuel from a high-pressure fuel distributor (10) by means of a high-pressure fuel supply path (14, 52, 44, 40), and having a nozzle needle (30), which opens and closes this injection nozzle (16) as a function of the pressure in a control chamber (58). In order to introduce fuel into the control chamber, an inlet conduit (62), which branches from the fuel supply path, feeds into this control chamber (58) and an outlet path (66, 78), which leads from this control chamber (58), permits fuel to flow out of the control chamber. A shutoff valve (70) can close a downstream section (66″) off from an upstream section (66′) of the outlet path. The downstream section and the upstream section of the outlet path feed into a valve chamber (78), which contains a movable shutoff element (76).

Abstract: In a fuel injection valve having a valve body (10), having a control pressure chamber (16) embodied in it and closed on one side by an actuating part (14) for a nozzle needle (12), which needle, controlled by the actuating part, is displaceable between a closing position and an opening position, having an inlet (18) to the control pressure chamber and an outlet (20) out of the control pressure chamber, the outlet being controlled by a control valve (24), in which the injected fuel quantity is metered with high precision. To that end, a displaceable throttle piston (32) is provided, which in a first position enables a partial opening stroke of the nozzle needle out of the closing position counter to a slight resistance, and in a second position enables a remaining opening stroke, immediately following the partial opening stroke, of the nozzle needle (12) into the opening position only counter to a higher resistance.

Abstract: A nozzle assembly includes a tip body having a lower end and defining a nozzle outlet. A needle sleeve is at least partially positioned in the tip body and includes a valve seat. A needle valve member is at least partially positioned within the needle sleeve, and is moveable between a closed position in contact with the valve seat and an open position out of contact with the valve seat. The needle valve member moves toward the lower end of the tip body when moving toward its open position. The nozzle assembly finds its preferred application in hydraulically-actuated fuel injectors having direct control needles.

Abstract: A fuel injector system 10 calculates a first derivative filtered signal and a second derivative filtered signal from an unpowered spool valve coil signal. When the spool valve 16 reaches the end of travel, either open or closed position, a flat slope f is generated on the falling edge of the bell shaped signal. The second derivative provides a readily apparent determination of when the steep slope occurs. A comparator 62 thereby need only determine when the second derivative is zero to identify that the spool valve has reached the end of travel.

Abstract: The invention relates to an injector for injecting fuel into the combustion chambers of an internal combustion engine, where the fuel compressed in a compression unit can be supplied via a pressure line to a nozzle chamber, which encompasses a nozzle needle of the injector. This nozzle chamber communicates with the injection nozzle protruding into the combustion chamber of the internal combustion engine, where the injector contains a fluid control unit. The fluid control unit is embodied as a hydraulic module, which is replaceably disposed in the housing of the injector and can either be actuated by an actuator or can be electromagnetically actuated.

Abstract: The invention relates to an arrangement for injecting fuel, which is at high pressure, into an internal combustion engine. An injector (25) encloses a pressure chamber (1), from which a high-pressure line (3) discharges into a control chamber (4) of a nozzle needle (5). Also contained in the injector (25) are two control valves (11, 12), which on the outlet side communicate with regions (9) of a lesser pressure level. One of the control valves (11, 12) that form the injection course (20) contains a pressure compensation system (34), by which the injection pressure course (20) can be varied by varying the stroke length (23) of the nozzle needle (5).

Abstract: The fuel injection apparatus has a pump unit (39), which pumps fuel at high pressure into a high-pressure conduit (10) communicating with an injection valve (1), and having a control valve (11), in which a pistonlike valve member (14) is guided with a sealing portion (114) in the bore (26), the sealing portion (114) being surrounded by a high-pressure chamber (16) that communicates with the pump work chamber (48). With one end, the valve member (14) protrudes one low-pressure chamber (18), which communicates with a fuel delivery system (58). A valve seat (22) is embodied in the bore (26) and cooperates with a valve sealing face (24), embodied on the valve member (14), to control the communication between the high-pressure chamber (16) and the low-pressure chamber (18).

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 outlet, 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: A simple propulsion engine utilizing unheated atmospheric air as the propellant, and driven by a single cycle (unicycle) engine with internal combustion cylinder and free piston is disclosed. A free piston with an annularly arranged thrust piston to divide a dual-diameter cylinder into two combustion chambers and two thrust chambers is provided. Scavenge feeder lines connected the thrust chambers to the combustion chambers via check valves provide exhaust scavenging, additional thrust output through exhaust nozzles, and feeding of fresh air into the combustion chambers. Also, pressure-actuated fuel injectors utilize pressure changes in respective combustion chambers to inject fuel at the appropriate time. The fuel injector includes an intensifier piston and pintle to raise the fuel pressure.

Abstract: An apparatus and process for generating a pulsed high-speed fluid jet that can be used to extinguish fires and/or to launch a projectile. A valve, such as an instant on-off valve, preferably operates in combination with a pressure accumulator. In a controlled manner, a pulsed fluid jet is generated and directed through a nozzle. The nozzle can draw into the fluid-jet an additive. The nozzle may also be used to launch a projectile using the fluid jet as a propellant.

Abstract: A fuel injector comprising a valve needle which is slidable within a bore and engageable with a seating to control fuel delivery through first and second outlet openings. The valve needle is moveable between a closed position and first and second fuel injecting positions. The fuel injector further comprises a fuel supply passage for supplying fuel under pressure to the bore and a control chamber which is arranged to receive fuel from the fuel passage, in use. The valve needle is acted upon in use by a force due to fuel pressure within the control chamber. An actuator arrangement controls fuel pressure within the control chamber, and a damping means are provided for damping movement of the valve needle away from the seating into the first or second fuel injecting position. The supply passage for fuel may be provided with a restricted flow passage which serves to limit the amplitude of pressure waves within the supply passage.

Abstract: A simple propulsion engine utilizing unheated atmospheric air as the propellant, and driven by a single cycle (unicycle) engine with internal combustion cylinder and free piston is disclosed. A free piston with an annularly arranged thrust piston to divide a dual-diameter cylinder into two combustion chambers and two thrust chambers is provided. Scavenge feeder lines connected the thrust chambers to the combustion chambers via check valves provide exhaust scavenging, additional thrust output through exhaust nozzles, and feeding of fresh air into the combustion chambers. Also, pressure-actuated fuel injectors utilize pressure changes in respective combustion chambers to inject fuel at the appropriate time. The fuel injector includes an intensifier piston and pintle to raise the fuel pressure.

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: 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 delay piston assembly in fluid communication with a high pressure chamber of the fuel injector. The pilot quantity of fuel flows through the delay piston 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: The invention relates to a fuel injection valve that has a valve member which can control a fuel outlet opening. The valve member has a first opening surface, which defines a first opening pressure chamber in the opening direction of the valve member, wherein the first opening pressure chamber is connected to a high-pressure fuel source and the pressure in the first opening pressure chamber produces a first opening force against the first opening surface. The valve member also has a first closing surface, which defines a first closing pressure chamber in the closing direction of the valve member, wherein the first closing pressure chamber is connected to the high-pressure fuel source and the pressure in the first closing pressure chamber produces a first closing force against the first closing surface.

Abstract: At least two torque paths between a driver and a camshaft distribute dynamic torque applied to the camshaft, allowing for cancellation of undesirable torque components. The second torque path has a greater number of gears than the first torque path, and acts as a constraint on the camshaft, ameliorating discontinuities in camshaft rotation due to sudden changes in load on the camshaft.

Abstract: A fuel injector pump in a direct-injection fuel delivery system for an internal combustion engine including a solenoid valve for controlling the transfer of fluid from the high pressure chamber of the camshaft driven pump pressure chamber to a fuel injector nozzle. A supply passage accommodates fuel delivery and return for fuel supplied by a fuel pump. A second independent leak flow path is provided to accommodate fuel leaking past a plunger of the high pressure pump, the fuel leak path extending to the fuel supply rather than leaking past the high pressure plunger of the pump to the engine lubrication oil circuit.

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 is provided which has an improved structure capable of adjusting fuel jet characteristics such as the quantity of fuel to be injected to an engine and a fuel injection time lag after the fuel injector is assembled. The fuel injector includes an air gap adjusting screw and a spring pressure adjusting screw. The air gap adjusting screw serves to change an air gap between a stator and an armature of a solenoid valve to adjust the quantity of fuel to a target one. The spring pressure adjusting screw serves to change a spring pressure urging a valve in a spray hole-closing direction to regulate a spray hole open duration, thereby adjusting the fuel injection time lag or the quantity of fuel.

Abstract: An injector for injecting fuel in a combustion chamber of an internal combustion engine has an injector housing, 2/2-way double valves received in the injector housing and coupled with one another for joint vertical movements, a hydraulic multiplier associated with the 2/2-way-control valves, a nozzle chamber which surrounds a nozzle needle and supplied with high pressure fuel by the hydraulic multiplier, the 2/2-way control valves in the housing being turned relative to one another and have valve bodies and guiding elements which surround the valve bodies.

Abstract: The invention relates to an injector for injecting fuel into the combustion chambers of an internal combustion engine. The inlet originating at a high-pressure collection chamber (common rail) discharges into the housing of the injector, in which a control part is received, movable vertically. The motion of the control part is effected via the pressure relief of a control chamber, provided in the housing of the injector, by means of an actuator-actuatable closing element. Upon triggering of the control part via the actuator-actuatable closing element, a seat valve embodied as a spherical control body closes or opens inlets and outlets.

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: An injector for injecting fuel into a combustion chamber of an internal combustion engine has a nozzle needle having a nozzle chamber with a nozzle inlet, a pressure convertor with a pressure chamber, two control valves arranged after the pressure convertor and having one control valves which releases and closes the nozzle inlet to the nozzle chamber of the nozzle needle, control chambers, and a high pressure line through which the control chambers and the pressure chamber of the pressure convertor are loaded with high pressure, one of the control chambers of the pressure convertor being connected by one of the control valves, while the nozzle inlet is provided with high pressure.

Abstract: The present invention provides a wide range injection timing, small dispersion, good response and simple structure.

Abstract: A piezoelectrically actuable fuel injector comprising an accumulator volume within which a piezoelectric stack is arranged, the accumulator volume being arranged to receive fuel from a source of pressurized fuel, in use. The piezoelectric stack carrying an end member which engages a surface associated with a piston member so as to apply a retracting force to the piston member upon a reduction in the axial length of the piezoelectric stack, the piston member being operable to control fuel pressure within a control chamber. A volume is defined between the end member and the surface associated with the piston member. The volume is provided with a vent arrangement to permit fuel within the volume to flow to a low pressure drain.

Abstract: The invention relates to an injector for reservoir (common rail) injection systems for direct-injection internal combustion engines in which a nozzle needle which is surrounded by a nozzle chamber is guided in an injector housing. The inlet of the nozzle chamber is closable and openable via an externally actuatable closing element. From the nozzle inlet, inlets branch off to control parts. The inlets are embodied as throttle elements, one of which is closable on the outlet side via a closing element.

Abstract: An injector for injecting fuel into the combustion chambers of an internal combustion engine in which a movable control part is contained in the housing of the injector and is guided in this injector housing to unblock the inlet to an injection nozzle when a closing element relieves the pressure in a control chamber or closes the inlet when a pressure is built up in the control chamber. The nozzle needle of the injector is associated with a piston element which encourages the closing movement of the nozzle needle and counteracts its opening movement.

Abstract: The invention relates to a method for machining control edges of a valve, preferably of a valve for a fuel injection device of an internal combustion engine, with the fuel injection device having at least one piston with control edges which co-operate with control edges fixedly connected to a valve, wherein respectively co-operating control edges are machined in one single machining operation with the aid of one single tool. The invention also relates to a fuel injection device with a valve which has control edges machined according to this method and which activates at least one injection valve body for closing off nozzle openings, wherein the valve is controlled by a control unit and is equipped with working connections by which a pressure medium is supplied to a control piston for displacing the injection valve body.

Abstract: A high pressure gaseous fuel injector for injecting natural gas or other gaseous fuels at high pressures (eg. 300 to 700 psig more or less) into combustion engines for improved efficiency, better performance and reduced environmental emissions. The fuel injector is powered by hydraulic signals from an electrohydraulic valve. The fuel injector includes an outer cartridge housing and a universal valve cartridge mounted therein. The cartridge comprises an activator body and a valve body secured together, and the valve body has a gas valve slidable therein. The stroke of the valve is adjustable by controlling the size of shims in the valve body assembly, thereby providing a universal valve cartridge that can be easily adapted to differing fueling requirements for models and sizes of engines. The valve body includes a spring chamber between upper and lower valve guides.

Abstract: The invention relates to a switching valve (10) comprising a valve body (20) in which a flow passage (24) is formed which opens with its one end into a work space (42). A valve plate (44) is accommodated in the work space (42) and can be moved between a closure position and an opening position. A closure element (50) is arranged between the valve plate (44) and the opening (26) of the flow passage (24) and closes the latter when the valve plate (44) is located in its closure position.

Abstract: Disclosed is an accumulator comprising a cylindrical shell including a cylindrical portion, a partitioning member for partitioning the interior of the shell into a hydraulic chamber and a gas chamber, and a port including a hydraulic fluid flow path for communicating the exterior of the shell and the hydraulic chamber. The variation of the pressure of a hydraulic fluid flowing into the hydraulic chamber is accommodated by expansion and compression of a gas in the gas chamber according to expansion and contraction of the partitioning member. The port is approximately airtightly inserted into the cylindrical portion of the shell, and is welded to an outer circumference of the cylindrical portion by means of welding.

Abstract: A fuel injector including an injector housing, a nozzle, a needle valve, and a nozzle return chamber. The nozzle discharges a fuel from the fuel injector. The needle valve has a first end adjacent to the nozzle to control the discharge of the fuel through the nozzle. The nozzle return chamber is adjacent a second end of the needle valve and receives a working fluid to bias the needle valve into the closed position.

Abstract: A method of controlling the injection rate and injection pressure of an electromagnetic fuel injector assembly having a pressure balanced control valve including a solenoid and a valve member subject to the pressures developed by the injector and actuated by the solenoid to close the valve member against the biasing force of a spring. The control valve is supported in a valve bore in the injector body. The valve bore includes a relieved portion. The method includes the step of providing a first level of current to the solenoid for moving the valve member from an open to a closed position allowing the pressure in the injector to rise, providing a reduced level of current to the solenoid at preselected times during the injector event to unbalance the forces acting on the valve member thereby slightly unseating the valve member to regulate the injection pressure and injection rate of the fuel injector and ending current to the solenoid thereby moving the valve member to its open position.

Abstract: A fuel injector includes a needle valve for injecting fuel from an injection port, a cylindrical member containing therein a pushing spring to the needle valve and a sleeve body for receiving the cylindrical member in an abutment condition so as to expose the injection port. A support portion having an enlarged diameter toward an inner circumference of the sleeve body is provided in a part of an outer circumference of the cylindrical member. A posture of the other cylindrical members may be corrected by the cylindrical member having the support portion.

Abstract: A fuel injector includes a pressure intensifying chamber communicating with a fuel supply passage through a check valve, a plunger for pressure-intensifying fuel introduced into the pressure intensifying chamber, and a needle valve for injecting the fuel pressure-intensified in the pressure intensifying chamber through an injection port, wherein there is provided in the fuel supply passage a throttle passage normally communicating with a fuel drain passage, air being bled during startup while leaking fuel.

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.