Abstract: A leak prevention device including an expandable chamber and control valve for preventing fuel leakage into the combustion chambers of a internal combustion engine equipped with a common rail fule injection system including open nozzle injectors and a shut off valve mounted in the common rail upstream of the fuel injectors to isolate, when closed, the fuel injectors from the source of fuel under pressure. The expandable chamber contains a variable volume held in its collapsed condition during engine operation and expanded upon engine shutdown sufficiently to prevent the flow of fuel from any injector into the corresponding combustion chamber.

Abstract: An electromagnetic fuel injection control valve positioned inside a fuel injector, i.e. a unit injector, for providing fast response and high pressure capability while minimizing the size and complexity of the injector. The control valve includes a valve housing having a supply inlet and fuel outlet, a center tube having a center passage and an annular valve seat, a control valve sleeve slidably mounted on the center tube and an actuator assembly having a coil spring, a stator and an armature. The control valve sleeve moves between an open position permitting fuel to flow between the supply inlet and the fuel outlet and a closed position which sealingly engages the annular valve seat for blocking the flow of fuel between the supply inlet and the fuel outlet. The coil spring biases the control valve sleeve in an open position and is positioned around the center tube. The stator is also axially positioned around the center tube and includes multiple poles.

Abstract: A stepped rotation fuel distribution valve for receiving and conducting metered, pressurized fuel pulses to the combustion cylinders of a diesel engine is provided. The valve includes a fuel distribution shaft rotatably mounted in a valve housing. The shaft includes a fuel discharge port that is sequentially registrable with fuel distributing passages in the housing that ultimately lead to the diesel fuel injectors associated with the combustion cylinders of the engine. A drive mechanism, which may include a stepper motor, intermittently rotates the fuel distributor shaft so that the shaft discharge port dwells in registration with one of the fuel distributing passages at the time a pressurized pulse of fuel is discharged through the shaft discharge port. The drive mechanism may also include either a set of timing gears or a spring coupling to achieve the desired intermittent rotation.

Abstract: A clamping load distributor and top stop disposed and connecting between a fuel injector body and a clamping device. The clamping load distributor functions as an intermediary to transmit the static clamping load from the clamping device to the fuel injector body. The clamping load distributor includes a cylindrically shaped main body having a bore extending therethrough that is disposed adjacent a coupling return spring. A cap is connected to the cylindrically shaped main body and functions as a top stop for limiting the outward axial movement of a mechanical linkage. The restriction on axial movement creates a small gap between the moving mechanical parts to allow a coating of lubrication to be obtained. The main body having a pair of clamp receiving portions formed therein for receiving a clamping load. An annular ring is formed on the bottom side of clamping load distributor radially inward from the clamp receiving portions for contacting the upper deck of the fuel injector body.

Abstract: A unit fuel injector is provided comprising an injector body containing a pumping chamber for receiving fuel at a low pressure level from a fuel supply passage for subsequent discharge at a high pressure level, a discharge orifice and a transfer passage communicating with the pumping chamber and the discharge orifice. A valve element is provided for movement between (i) an advanced position wherein the supply passage communicates with the pumping chamber through the transfer passage and (ii) a retracted position wherein communication between the supply passage and the pumping chamber is blocked to allow fuel to flow from the pumping chamber through the transfer passage and out the discharge orifice.

Abstract: In accordance with a preferred embodiment of the invention, a solenoid operated unit fuel injector, for internal combustion engines of the type which are capable of having distinct timing, metering and injection periods, and in which the same supply line serves for the delivery of fuel to both a timing chamber and a metering chamber, is improved by providing a drilling in the injector barrel which leads directly from the timing fluid flow portion of the fuel supply circuit to an injector fuel drain path, and mounting a C-shaped spring valve on the injector body for controlling dumping of fuel through the drilling at a location above that of the timing and metering spill ports.

Abstract: A pump-line-nozzle fuel injection system in which a supply pump is coupled to a high pressure pump having a plurality of pumping cylinders, each of which has a cam-driven timing plunger and a floating metering plunger. During the retraction stroke, flow to a timing chamber formed between the pistons is blocked by a solenoid valve while the fuel passes into a metering chamber, at the discharge side of the pump, which is closed relative to the high pressure delivery line by a delivery valve. Once the proper quantity of fuel has been metered, the solenoid valve opens allowing fuel to flow into the metering chamber, balancing the pressure on opposite sides of the metering piston, so as to prevent the metering plunger from retracting further as the timing plunger continues to retract. During the compression stroke, at the appropriate time for commencement of injection, the solenoid valve recloses creating a hydraulic link between the metering and timing plungers, so that the fuel is pressurized.

Abstract: A hydraulic tappet for use in the fuel injector drive trains of compression ignition or diesel internal combustion engines are provided which optimize injector timing for improved fuel economy. One embodiment of the hydraulic tappet of the present invention includes a dampened pressure regulating feature which determines blow down pressure. A second embodiment of the hydraulic tappet of the present invention includes a dampening load cell feature which allows the blow down pressure of the load cell to be increased and injection timing to be optimally advanced.

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 unit fuel injector is provided comprising an injector body containing a pumping chamber and a valve element provided for movement between (i) an advanced position wherein a supply passage communicates with the pumping chamber through a transfer passage and (ii) a retracted position wherein communication between the supply passage and the pumping chamber is blocked to allow fuel to flow from the pumping chamber through the transfer passage and out the discharge orifice. In one embodiment the valve element includes a control valve integrally formed with a tip valve, and a force balancing element for tending to balance the forces acting on the valve element by reducing the effective cross-sectional area upon which fluid pressure operates. The control valve, whether formed integral with or separate from the tip valve, extends through the solenoid to engage a valve seat formed adjacent the pumping chamber.

Abstract: A fuel leakage prevention system for preventing undesired leakage of fuel into the combustion chambers of an internal combustion engine equipped with a pressure/time, cam actuated unit fuel injection system. The system includes a main housing containing an evacuatable chamber adapted to be connected by a first fluid conduit to a source of sub-atmospheric pressure by a check valve and manual shut off valve. The evacuatable chamber is also adapted to be fluidically connected to a common rail supplying fuel to the injectors by a solenoid controlled valve which is open during engine shutdown and closed during engine operation whereby fuel is withdrawn from the injectors by the vacuum upon engine shutdown.

Abstract: An air fuel control system for an internal combustion engine is disclosed. The control system includes an air pressure responsive device for modulating mechanically the flow of fuel into the engine in response to the pressure of air within the intake manifold. The pressure-responsive device includes first and second chambers, separated by a diaphragm being attached to a piston, with the first chamber which is connected to the intake manifold by an air line. The air fuel control system further includes a fuel metering device for controlling the flow of fuel into the air-fuel control in response to intake manifold air pressure including a barrel and plunger assembly with the barrel inlet port being specifically configured to accommodate both the no-air and transition-curve fuel rail pressures. The barrel profile is designed to meter fuel quickly and precisely in response to changes in manifold air pressure.

Abstract: The present invention is directed to open nozzle unit fuel injectors for injecting a metered quantity of fuel into the cylinder of an internal combustion engine, as synchronously controlled by a drive train, wherein the unit fuel injector comprises a body with an axial bore and a plunger assembly movable therein between a retracted position and an advanced position. The plunger includes a major diameter section, slidably movable in the axial bore to open and close a fuel supply orifice and a minor diameter section which extends in a bore of a cup portion of the injector body. The cup portion has an internal surface including plural diameter portions connected by an annular step.

Abstract: A unit fuel injector is disclosed to be used in a fuel injection system of an internal combustion engine wherein each unit injector is operated independently from one another and in synchronization with the internal combustion engine. Specifically, the unit injector in accordance with the present invention includes a reciprocating plunger assembly within the unit injector that controls fuel metering as well as fuel injection, and a valve device positioned between a minor diameter plunger section and a cup of the unit injector so as to permit fuel flow in one direction for fuel injection and to restrict flow of gases in the opposite direction. The valve device effectively reduces carbon build-up on the injector surfaces and increases injector longevity while reducing maintenance. Moreover, fuel metering is accurately controlled without substantial carboning flow losses.

Abstract: A fuel injector having both stepped and infinitely variable timing is disclosed. The fuel injector includes an injector housing and a plunger wherein the plunger includes an axial bore formed in the top of the plunger. A plunger top is mounted within the axial bore and is translatable between an upper position and a lower position. A coil spring having a predetermined spring rate is disposed in the axial bore for biasing the plunger top in the upper position. An upper and a lower piston are disposed above the plunger and are translatable within the injector housing. A timing chamber is formed between the upper piston and the lower piston. When the timing chamber contains timing fluid, the fluid serves as a hydraulic link between the upper and lower pistons and the fuel injector operates at a first level of advanced timing.

Abstract: An improved, simplified pressure/time dependent fuel injector assembly for injecting fuel intermittently into a combustion chamber of an internal combustion engine. The injector assembly includes a unitary or single-piece injector body which has at least one groove-like channel on the exterior surface thereof. The channel is closed and sealed by a sleeve which is press-fit about that portion of the injector body on which the channel lies. For reciprocation within the injector body, there is provided an injector-plunger assembly which includes a top stop mechanism for adjustably setting the distance traveled by the plunger assembly during the reciprocatory movement thereof.

Abstract: A tamper-proof adjustment screw arrangement for a vehicle fuel supply system for preventing tampering with the setting of an adjustment screw that is situated in a common recess with a component requiring the availability of continued access. In a preferred embodiment, a tamper-proofing shield coacts with the configuration of a portion of a recess having a stepped bottom wall and with a spanner jam nut on the adjustment screw to create a press fit mounting of the shield that makes it exceedingly difficult to pry off the tamper-proofing shield. As an additional safeguard, the spanner nut is designed to require a special tool for loosening thereof.

Abstract: This disclosure relates to a unit-type fuel injector for an internal combustion engine such as a reciprocating piston internal combustion engine. The injector includes an injector body forming a plunger bore, and a plunger that reciprocates in the bore. A fuel supply passage and a drain passage are formed in the body, and a fuel injection chamber is formed at the lower end of the plunger bore. A feed hole connects the chamber with the supply passage, and a scavenge passage connects the supply and drain passages. During a retracted plunger, or fuel metering, portion of the injector cycle, the plunger opens the feed hole and closes the scavenge passage, and during a down plunger, or scavenging, portion of the injector cycle, the plunger closes the feed hole and opens the scavenge passage. An annular groove is formed between injector parts and surrounds the chamber, and the groove collects leakage. A restricted bleed hole connects the groove with the low pressure drain and removes the leakage.

Abstract: A turbocharger assembly is provided for use with an internal combustion engine. The assembly includes a compressor chamber having a compressor wheel disposed therein and a turbine chamber having a turbine wheel disposed therein. The two wheels are affixed to a rotating shaft. A lubricated bearing assembly is disposed between the chambers and encompasses the shaft. A dynamic first seal encompasses the shaft and is disposed between the bearing assembly and the compressor chamber. A second seal encompasses the shaft and is disposed between the bearing assembly and the turbine chamber. Controlled first means is provided for braking rotation of the shaft. Second means is provided which, when the first means is in a shaft-braking mode, causes a predetermined gaseous pressure to be exerted on the first seal inhibiting migration of the lubricant from the bearing assembly to the compressor chamber.