Abstract: A fuel injector, especially an injector for fuel injection systems in internal combustion engines, has a piezoelectric or magnetostrictive actuator. The actuator, via a valve needle, activates a valve-closure member, which cooperates with a valve seat surface to form a sealing seat. The actuator can be actuated in a first direction of motion. In contrast, the valve-closure member can be moved by the valve needle in a second direction of motion (40) that is essentially perpendicular to the first direction of motion.

Abstract: The present invention relates to fuel injectors having a free floating plunger. Traditional tappet assemblies include a plunger that is mechanically coupled to the tappet, and therefore, cannot be uncoupled over a portion of its movement during an injection event. In the event of a plunger seizure in a traditional tappet assembly, the tappet spring can be prevented from expanding, which can cause major valve train and engine damage. In addition, because the plunger in traditional tappet assemblies is moved to its upward position under the action of the tappet spring, the fuel passages can depressurize if fuel cannot refill the fuel pressurization chamber as quickly as the plunger retracts, causing cavitation bubbles. Therefore, the present invention utilizes a plunger that is not mechanically coupled to the tappet and can uncouple from the tappet during the injection event to address these and other problems related to plunger wear and failure.

Abstract: A fuel injector includes a tappet assembly mounted on an injector body. At least one of the tappet assembly and the injector body define a retention opening therethrough. A retention member is positioned in the retention opening and concealed by at least one of the tappet assembly and the injector body. The tappet assembly is moveable with respect to the injector body an unadjustable displacement distance between an advanced position and an extended position. The height of the retention opening is less than the unadjustable displacement distance.

Abstract: A solenoid actuated valve includes a valve body that defines a first passage and a second passage. The solenoid is attached to the valve body and has an armature. A multi-piece valve member is attached to the armature. At least one of the multi-piece valve member and valve body define a small passage and a large passage. The multi-piece valve member has a first configuration in which both the small and large passages are closed. The multi-piece valve member has a second configuration in which the small passage is open between the first passage and the second passage, but the large passage remains closed. The multi-piece valve member has a third configuration in which the large passage is open between the first passage and the second passage. The valve finds a preferred application as a control valve in a hydraulically-actuated fuel injector.

Abstract: A hydraulically actuated fuel injector includes an injector body containing an intensifier piston with a hydraulic surface exposed to fluid pressure in a hydraulic pressure cavity. This hydraulic surface includes an annular taper and moves within a bore due to the pressure in the hydraulic pressure cavity. Prior to the injection event, the intensifier piston is in a retracted position that partially blocks at least one actuation fluid supply passage. At the initiation of the injection event, the partial blocking of the actuation fluid passage results in a slower initial movement rate of the intensifier piston. The injection flow rate is a function of the speed of the intensifier piston. The initial rate shaping is accomplished by controlling the initial speed of the intensifier piston by at least partially blocking one or more of the actuation fluid supply passages.

Abstract: A hydraulically-actuated fuel injector includes an injector body that defines an actuation fluid inlet, a first actuation fluid cavity, a second actuation fluid cavity and a nozzle outlet. A piston is positioned in the injector body and is moveable between a retracted position and an advanced position. The piston has a primary hydraulic surface exposed to fluid in the first actuation fluid cavity, and an opposing hydraulic surface exposed to fluid in the second actuation fluid cavity. A control valve includes a spool valve member that is moveable a distance between a first position and a second position. The first actuation fluid cavity is closed to the actuation fluid inlet when the spool valve member is in its first position. The first actuation fluid cavity is open, but the second actuation fluid cavity is closed, to the actuation fluid inlet when the spool valve member is moving through a first portion of the distance.

Abstract: A heavy diesel fuel injection pump with precipitate build-up inhibiting features includes a pump body that defines a plunger bore. The plunger has a top end separated from a bottom end by a side surface, and is moveable in the plunger bore between a retracted position and an advanced position. A portion of the plunger bore and the bottom end of the plunger define a pump chamber containing heavy diesel fuel. The top end of the plunger is exposed to lubricating oil. The lubricating oil mixes with the heavy diesel fuel along a guide portion of the side surface of the plunger that has a tight clearance with respect to the plunger bore. At least one of the pump body and the guide portion of the plunger define a plurality of cleaning grooves located adjacent the guide portion.

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 fuel injection nozzle includes a lift piece located on the side of a nozzle needle. A protrusion of the lift piece and the distal end of a push rod are held by a spring seat with a specified clearance therebetween as a prelift. The adjustment of the prelift can be performed only by taking out the lift piece to be adjusted, so that the adjusting work of the prelift, accompanied with disassembly of the fuel injection nozzle becomes easy and fuel injection characteristics are improved.

Abstract: Fuel injection rate shaping is integrated into the pressure intensification stage of a hydraulically actuated fuel injector having a pressure intensifier. In a first embodiment, the pressure intensification plunger is formed of two parts creating a damping chamber therebetween from which fluid is forced out through orifices in a lower one of the plunger parts during an initial phase of displacement of the upper part. Thus, injection will be performed initially at a lower pressure and rate, which increases once the plunger parts make contact. In a second embodiment, a throttled flow is set via a restrictor housing that telescopingly receives the upper plunger part, so that a lower injection rate occurs while fluid is bled off through a restricted flow path between the restrictor housing and the upper plunger part, and a higher injection rate is produced once a port in the upper plunger clears the restrictor housing.

Abstract: A fuel injector includes an injector body with a plunger bore, a nozzle chamber, and a nozzle outlet that opens to the nozzle chamber. A plunger is positioned to reciprocate in the plunger bore between an advanced position and a retracted position. A portion of the plunger and a portion of the plunger bore define a fuel pressurization chamber. At least one of the injector body and the plunger define a main passage extending between the fuel pressurization chamber and the nozzle chamber. At least one of the injector body and the plunger define a restricted passage extending between the fuel pressurization chamber and the nozzle chamber. The restricted passage restricts flow of fuel to the nozzle chamber over the beginning portion of each injection event. The main passage is substantially closed over a portion of the plunger's movement between its retracted position and its advanced position.

Abstract: A hydraulically actuated fuel injector includes an injector body defining an actuation fluid chamber that opens to an actuation fluid drain, an actuation fluid inlet and a piston bore, and further defining a nozzle chamber that opens to a plunger bore and a nozzle outlet. A control valve, positioned in the injector body, has a first position that opens the actuation fluid inlet and closes the actuation fluid drain, and a second position that closes the actuation fluid inlet and opens the actuation fluid drain. A piston, positioned in the piston bore. A plunger, positioned in the plunger bore, is moveable between an upper position and a lower position. A needle valve member, positioned in the nozzle chamber, is moveable between an open position in which the nozzle outlet is open and a closed position in which the nozzle outlet is blocked. A portion of the plunger bore and the plunger define a fuel pressurization chamber that opens to the nozzle chamber.

Abstract: A fuel injector having a plurality of spaced apart apertures modifies the rate of fluid flow of the fuel injectors. The apertures are sequentially opened by movement of the intensifier piston in a piston bore passing actuating fluid flow at an increasing rate to a piston pressure chamber defined by a first end surface of the intensifier piston, a closed end surface of the piston bore and the cylindrical surface of the piston bore. The opening of the spaced apart fluid delivery apertures provide a stepped rate trace. The stepped rate trace allows less fuel to be injected into the combustion chamber by injecting the fuel slower during the early phase of the combustion process where combustion is less harsh.

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 intensifier cleaning probe is provided which compresses the cleaning fluid and delivers it through a central reciprocating cylinder rod which also serves to advance an attached cleaning rod with an engine oil passage or the like.

Abstract: In a hydraulically actuated fuel injector, each injection event is initiated and terminated by opening an actuation fluid cavity within the injector to a high pressure inlet source and a low pressure drain, respectively. The present invention is intended to provide a more abrupt ending to each injection event in order to improve performance and exhaust emission quality. The present invention incorporates a hydraulically actuated spill valve into the injector body. The spill valve exploits the pressure differential existing between the fuel pressurization chamber of the injector toward the end of each injection and the drop in pressure in the actuation fluid cavity. This pressure differential is exploited to hydraulically open a spill port to allow the residual fuel pressure to dissipate into a fuel return passage rather than dribble out of the injector nozzle while the needle check is moving toward its closed position.

Abstract: The staged plungers can be incorporated into virtually any type of fuel injector that utilizes plunger movement to raise fuel pressure in order to initiate and sustain an injection event. The staged plungers include an outer plunger with a rate shaping spill port. An inner plunger having a rate shaping bore is positioned to reciprocate within the inner bore of the outer plunger. A compression spring biases the inner plunger toward an advanced position relative to the outer plunger. Toward the beginning of the staged plungers' downward stroke at the beginning of an injection event, their relative movement produces rate shaping in the fuel leaving the injector as well as producing a split injection as the rate shaping spill bore of the inner plunger opens to the rate shaping spill port of the outer plunger.

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 non-accumulator-type hydraulic electronic unit injector assembly can be converted to an accumulator-type hydraulic electronic unit injector assembly simply by subjecting the nozzle needle of the injector to downwardly closing forces arising from fluid pressure in the high pressure chamber of the intensifier. This modification causes the needle to remain seated upon intensification of fluid pressure in the high pressure chamber and permits fuel injection to commence only upon subsequent pressure decay in the high pressure chamber. An accumulator volume is formed beneath the blowback avoidance check-valve of the converted injector and can, if necessary, be enlarged by adding the spring chamber of the assembly to the accumulator volume. The resulting assembly could conceivably be retrofitted into an existing injection system on site, or could be assembled as new construction using primarily stock non-accumulator-type assembly components.

Abstract: To provide a fuel injection pump which can sufficiently and stably supply fuel to a fuel pressurization chamber during a fuel intake stroke, a plunger chamber, a spill port and a spill passage are mutually communicable, while a reflux passage, an intake gallery, an intake passage, an intake port and the plunger chamber are mutually communicable. A reflux passage communicates with a damping chamber through a communication passage. The spill passage and the reflux passage communicate with each other, and when a spill valve opens, high-pressure fuel within the plunger chamber spills from the spill valve and into the intake gallery through the reflux passage, causing pulsation having a pressure level difference to the spill fuel. When the pulsation wave passes through the damping chamber, as the level difference in the pulsation wave is reduced, a sufficient quantity of fuel can stably be supplied from the intake gallery to the plunger chamber.

Abstract: An actuation valve for a hydraulically-operated fuel injector includes an actuator having a plunger and a spool valve coupled to the plunger. The spool valve includes a high pressure port and is operable by the actuator to selectively place the high pressure port or the low pressure port in fluid communication with an injection mechanism of the injector.

Abstract: A hydraulically actuated fuel injector includes an intensifier piston with a tapered or conical protuberance and an injector body with a conical seat. During the pre-injection stage, the piston is spring loaded to seat its conical protuberance against the conical seat of the injector body. To start the injection, actuation fluid is admitted to the injector. The injector actuation volume is pressurized and the pressure acts initially only on the top of the conical protuberance of the piston. The displacement of the piston is temporarily retarded during the first stage of injection due to a throttling effect in allowing the high pressure fluid to act on the remaining top surface of the piston. The throttling effect is provided by the relatively narrow flow area between the conical protuberance and the conically shaped seat.

Abstract: A fuel injector nozzle assembly has a housing defining a blind bore and at least one injection orifice at the bottom portion thereof and a fuel injection passage fluidly connecting the bottom portion of the blind bore and a source of pressurized fluid. A primary check is disposed in the blind bore. A spring between the housing and the check establishes a first valve opening pressure. A secondary check is slidably disposed in the fuel injection passage, defining an aperture therethrough. A secondary check spring is disposed between the secondary check and the housing, establishing a second valve opening pressure.

Abstract: A fuel injector assembly for a fuel injection system has a fuel pumping assembly with a fuel inlet and a fuel nozzle for causing fuel to be periodically pumped from the fuel inlet through the nozzle. The fuel injector assembly has an electro-hydraulic control valve associated with the fuel pumping means. The control valve comprises a housing, a first conduit formed in the housing and fluidly coupled to the fuel pumping means, a second conduit formed in the housing and fluidly coupled to a source of pressurized hydraulic fluid. A valve element is disposed in the housing and is reciprocable between a first position in which the first conduit is fluidly coupled to the second conduit and a second position in which the first conduit is fluidly isolated from the second conduit. The control valve also includes a pair of electrically energizable electromagnetic devices for controlling the reciprocation of the valve element.

Abstract: This invention relates to accumulator injectors for a gas and/or liquid fueled diesel engine fuel injection system. Such structures of this type, generally, allows for variable injection timing and duration while providing a multiple fuel capability by changing the fuel distribution/atomization nozzle.

Abstract: The invention is a pulsed, hydraulically actuated fuel injector ignitor system for an internal combustion engine with combustion chambers and a fuel injector, comprising an outer shell containing a fuel inlet cavity, a fuel supply and scavenging chamber supplied with fuel from the inlet cavity through the rod bore of the injector rod, and a fuel pressure chamber, which is resupplied through check valve from the supply chamber after each injection has taken place. The pressure chamber has a poppet valve responsive to a predetermined fuel pressure in the pressure chamber, resulting from the intrusion of injector piston into the pressure chamber, thereby spraying fuel into the combustion chamber through a hot-throated venturi and igniting the fuel as it passes through venturi. Concentric open-ended cylinders form the control body assembly and are positioned between the base assembly and the fluid manifold head cap and having alternate open-ended cylinders in communication with sliding contact.

Abstract: An electronically controlled, microprocessor equipped fuel injection system for new manufacture or retrofit of existing diesel engines has a tubular injector provided with a fuel pressure amplification chamber next adjacent and communicating directly with an injector nozzle at one end of the tube; the nozzle has atomizing orifices for spraying the pressure amplified fuel into the engine cylinder. A fuel flow controlling solenoid is provided at the opposite end of the tube and all component parts in the tube between the nozzle and a spring loaded solenoid armature are disposed along a common axis extending longitudinally of the tube. Such parts include a fuel pressure amplification plunger, a hydraulic pumping piston for actuating the plunger, a spool valve shiftable toward and away from the armature and a needle valve normally closing the orifices.

Abstract: In a fuel injection system including an injection distributor pump delivering fuel at a medium delivery pressure, a plurality of fuel injection valves each associated with a respective engine cylinder and each having a fuel injection opening for injecting fuel into its associated cylinder and a conduit leading to the injection opening, and a pressure booster associated with each valve and connected between the conduit of its associated valve and the pump for boosting the pressure at the opening from the medium pressure produced by the pump to a higher pressure required for fuel injection via the opening, the pressure booster associated with each valve being composed of a stepped piston having oppositely oriented end faces of unlike effective area, a housing in which the piston is slidably mounted and presenting a first working chamber associated with the larger end face of the piston and communicating with the pump, and a second working chamber associated with the smaller end face of the piston and communicat

Abstract: A diesel fuel injector having two separate annular or annulus-to-annulus dumps for providing a variable and a fixed orifice rapidly and controllably terminating injection and for controlling the impact velocity of the injector's intensifier piston against a mating stop. The injector further includes a middle chamber that is always connected to a low pressure vent to permit the collection and diversion of leakage fuel away from the middle chamber. The intensifier piston includes an upper member that is received within a stepped bore. The intensifier piston is loosely received within a lower member to permit relative motion therebetween for preventing the gall-up of the intensifier piston against the walls of the cooperating stepped bore.

Abstract: A diesel fuel injector having two separate annular or annulus-to-annulus dumps for providing a variable and a fixed orifice rapidly and controllably terminating injection and for controlling the impact velocity of the injector's intensifier piston against a mating stop. The injector further includes a middle chamber that is always connected to a low pressure vent to permit the collection and diversion of leakage fuel away from the middle chamber. The intensifier piston includes an upper member that is received within a stepped bore. The intensifier piston is loosely received within a lower member to permit relative motion therebetween for preventing the gall-up of the intensifier piston against the walls of the cooperating stepped bore.

Abstract: A fuel injector for use on an internal combustion engine which includes a housing enclosing a cylindrical barrel having a bore formed therein. The barrel cooperates with the housing to form an annular cavity therebetween. Axially movable within the bore is a plunger and a piston which are spaced apart. The housing also has a nozzle situated at one end which communicates with the bore for releasing fuel into the combustion chamber of the engine. Formed within the bore between the plunger and the piston is a timing chamber and formed between the piston and the nozzle is a metering chamber. Pressurized fluid is directed into the timing chamber, into the metering chamber and into one end of the annular cavity by passages which are arranged in the housing and in the barrel. The passage leading into the end of the annular cavity has a control valve positioned across it such that fluid pressure can be varied to that end of the annular cavity.

Abstract: A low pressure sealing arrangement for a fuel injector which includes a housing containing a cylindrical barrel having a bore formed therein. Within the bore is positioned an axially movable plunger and piston which form a timing chamber therebetween. An inner surface of the housing cooperates with an outer surface of the barrel to form an annular cavity and a passage connects one end of the annular cavity with the timing chamber. Located within the annular cavity itself is arranged a pressure activated valve which is surrounded by a cylindrical sleeve. The pressure activated valve is spring biased to a closed position and is movable between an open and a closed position to regulate the flow of fluid into the timing chamber. The outer surface of the pressure activated valve cooperates with the inner surface of a cylindrical sleeve to form a first low pressure seal therewith when the valve is in the closed position.

Abstract: A fuel injection system has an injection distributor pump and a plurality of fuel injection valves supplied with pressurized fuel from the pump and projecting into the combustion chamber of respective cylinders of an internal combustion engine served by the fuel injection system. The injection distributor pump generates a fuel delivery pressure of medium magnitude. With each fuel injection valve there is associated a pressure booster for amplifying the pressure of the fuel from the value of medium magnitude to an ejection pressure required for injecting the fuel by the fuel injection valve into the respective engine cylinder.

Abstract: A hydraulically operated fuel injector for compression-ignition engines which includes an electronically or pneumatically operated hydraulic pilot-control valve which is supplied with fuel under substantially constant pressure from a pump driven directly or indirectly by the engine. The pilot-control valve is connected by supply and exhaust passages to a slave valve which in turn controls the admission of fuel to a charging cavity located adjacent to an outlet valve to the combustion chamber. The slave valve is a stepped diameter piston which functions as a pressure amplifier for the fuel supply to the combustion chamber. Fuel from the pump which is received at relatively low pressure through the slave valve is amplified to high pressures sufficient to overcome compression and combustion pressures of the engine and the resistance of spring seated injector outlets and/or the fuel supply orifice(s).

Abstract: The subject fuel injection means, disclosed herein with one of various types of internal combustion engines with which it may be employed, comprises a fuel pumping plunger, the pumping stroke of which is controlled by an inclined surface of a manually operable slide element. Said plunger is urged in a pumping direction by fluid pressure applied thereto from compression generated in the engine's combustion chamber and is spring biased in a non-pumping direction. A solenoid, operationally timed to the rotation of the engine's crankshaft, coacts with the pumping plunger to assure starting of the plunger's pumping stroke in proper timed relation to the compression and firing of an explosive charge in the engine's combustion chamber. In said pumping stroke, the plunger closes a fuel inlet to a related pump chamber and forces fuel from said pump chamber, past a one way check valve and into the engine's combustion chamber.

Abstract: This disclosure deals with a fuel supply system for an internal combustion engine, the supply system including injectors for injecting fuel into the combustion chambers of the engine, and hydraulic means for adjusting the timing of injection. The hydraulic timing adjustment is included in each of the injectors of the system. The hydraulic timing adjustment responds to parameters of the engine, such as load and/or speed, for varying or holding constant the time of initiation of injection, and the adjustment is quickly responsive to changes in the parameters.