Abstract: A common rail fuel injection system for a motor vehicle, comprising a distributor rail (16) fluidly connected to at least one fuel injector (18), an accumulator chamber (14) fluidly connected to the distributor rail, a high pressure fuel pump (10) that has an inlet for receiving fuel from a low pressure feed system (20, 22, 24) and an outlet chamber (12) for proving fuel at high pressure to the accumulator (14). A recirculation valve (52) is fluidly connected to the pump outlet chamber (12), the accumulator (14), and the low pressure feed system, wherein at a first position the recirculation valve fluidly aligns the outlet chamber (12) with the accumulator (14) and in a second position aligns the outlet chamber with the low pressure system for recirculation of fuel through the high pressure pump at the low pressure.

Abstract: A common rail fuel injection system for a motor vehicle, comprising a distributor rail (16) fluidly connected to at least one fuel injector (18), an accumulator chamber (14) fluidly connected to the distributor rail, a high pr3essure fuel pump (10) that has an inlet for receiving fuel from allow pressure feed system (20, 22, 24) and an outlet chamger (12) for proving fuel at high pressure to the accumulator (14). A recirculation valve (52) is fluidly connected to the pump outlet chamber (12), the accumulator (14), and the low pressure feed system, wherein at a first position the recirculation valve fluidly aligns the outlet chamber (12) with the accumulator (14) and in a second position aligns the outlet chamber with the low pressure system for recirculation of fuel through the high pressure pump at the low pressure.

Abstract: A fuel injector to inject fuel into a cylinder of an internal combustion engine when installed therein. The injector has an injector body which defines an interior cavity, a movable needle valve which cooperates with the interior body to define a variable-volume control chamber and a control valve for selectively blocking and permitting fluid communication among the control chamber, the high-pressure fuel supply, and the low-pressure fuel return. Such selectively controlled variation of the volume of the control chamber varies the position of the needle valve to selectively permit or prevent fluid communication between the high-pressure fuel supply and the engine cylinder. The control valve for selectively permitting fluid communication is preferably force balanced by relatively low forces acting thereon.

Abstract: A fuel injector to inject fuel into a cylinder of an internal combustion engine when installed therein, the engine having a high-pressure fuel supply which delivers fuel to the injector and a low-pressure fuel return which removes fuel from the injector. The injector has an injector body which defines an interior cavity, a movable needle valve which cooperates with the interior body to define a variable-volume control chamber and another value for selectively permitting fluid communication between the control chamber and (1) the high-pressure fuel supply; and (2) the low pressure fuel return. Such fluid communication permits controlled variation of the volume of the control chamber which, in turn, varies the position of the needle valve to selectively permit or prevent fluid communication between the high-pressure fuel supply and the engine cylinder. The valve for selectively permitting fluid communication is preferably force balanced by relatively low forces acting thereon.

Abstract: A fuel injector employs at least one sensing device for sensing changes in the thermodynamic properties of the fuel within the injector to thereby monitor injector performance during usage. In some embodiments, advantageously placed temperature sensors are employed to detect the release of thermal energy which occurs when the potential energy of a fuel at high-pressure is suddenly converted into kinetic energy by lowering the pressure of the fuel. Other embodiments of the instant invention employ advantageously placed pressure sensors to detect sudden changes in fuel pressure which occur during the course of the injection cycle. Whereas the sensing devices of the instant invention can be placed at a variety of locations, they are preferably placed to detect changes in the thermodynamic properties of the fuel flowing within an injector where such changes are appreciably large during injector usage.

Abstract: A rotary distributor fuel injection pump having a fuel system for circulating fuel continuously from a fuel supply pump via an end chamber at one end of the distributor rotor and an annular fuel chamber surrounding the distributor rotor to a return line and a pressure regulator in the return line for regulating the upstream pressure and continuously returning excess fuel to the supply pump. An electrical control valve is selectively opened during the pumping strokes to spill fuel into the end chamber and terminate the fuel injection event. An auxiliary passage in the rotor resets the pressure in the distributor outlets to approximately the same initial pressure. In an air purging mode of operation, the control valve is held closed until after the distributor port moves out of registry with each distributor outlet to prevent back flow to the end chamber.

Abstract: An electrical control unit having a microprocessor and a network of counters for governing the electrical operation of a fuel control valve of a fuel injection pump. Four subtraction counters are preset by the processor; one is used as a time counter indexed by time pulses and three are used as pump angle counters indexed by pump clock pulses generated for each predetermined increment of pump rotation. Two of the pump angle counters are employed to precisely open and close the valve for regulating the fuel injection timing and quantity--the total quantity in a normal mode of operation and a pilot quantity in a pilot injection mode. In the pilot mode, the third pump angle counter regulates the main injection quantity and the time counter regulates the time delay between the pilot and main injections.

Abstract: A hole type fuel injector with a nozzle body and needle valve having cooperating inner and outer metering rings providing a metering passage (a) to provide an initial reduced rate of fuel injection during an initial increment of valve lift, (b) to maintain fuel pressure at the valve seat to reduce fuel dribble and cavitation erosion during a corresponding last increment of valve closure and (c) to prevent secondary fuel injection.

Abstract: One spring and two spring embodiments of a fuel injector having a nozzle body and needle valve with cooperating inner and outer metering rings providing a metering passage which (a) meters fuel at a reduced rate during an initial increment of valve lift, (b) assists in maintaining fuel pressure at the valve seat to reduce fuel dribble and cavitation erosion during a corresponding last increment of valve closure and (c) dampens secondary pressure waves to prevent secondary fuel injection.

Abstract: An internal combustion engine fuel injection system having a reciprocating charge pump and a bidirectional flow, solenoid valve for precisely regulating the fuel injection timing by precisely regulating the intake charge quantity of fuel supplied to the charge pump during each intake stroke and for precisely regulating the fuel injection quantity by precisely regulating the spill termination of the high pressure delivery of fuel during each pumping stroke. An electrical controller having a data processor timely energizes and deenergizes the solenoid valve and adjusts the charge pump stroke timing, if adjustable, for adjusting the fuel injection timing and quantity. A start-of-pumping sensor or charge pump stroke timing sensor is used to provide a closed loop feedback, or in the alternative where the charge pump stroke is not adjustable, a calibrated input is used in lieu of a charge pump stroke timing sensor.

Abstract: An electronic unit injector employs an expandable chamber which expands as pressure in the injector increases between a pair of threshold pressures. The expansion of the chamber results in a two-phase rate of injection of the injector whereby the initial injection rate is significantly lower than the second injection rate. In one embodiment, the expandable chamber is formed by a pin which is displaceable in a cap mounted to the injector body. The pin bottoms against the cap to define the phase transition.

Abstract: An internal combustion engine fuel injection system having a reciprocating charge pump and a bidirectional flow, solenoid valve for precisely regulating the fuel injection timing by precisely reglating the intake charge quantity of fuel supplied to the charge pump during each intake stroke and for precisely regulating the fuel injection quantity by precisely regulating the spill termination of the high pressure delivery of fuel during each pumping stroke. An electrical controller having a data processor timely energizes and deenergizes the solenoid valve and adjusts the charge pump stroke timing, if adjustable, for adjusting the fuel injection timing and quantity. A start-of-pumping sensor or charge pump stroke timing sensor is used to provide a closed loop feedback, or in the alternative where the charge pump stroke is not adjustable, a calibrated input is used in lieu of a charge pump stroke timing sensor.

Abstract: An accumulator injector employs a shuttle piston assembly to produce a pilot injection prior to the primary fuel injection of the injector and to control the injection rate. The shuttle piston communicates with the control chamber and the accumulator chamber of the injector to provide a controllable pressure bleed means for controlling the valve needle lift of the injector.

Abstract: Engine exhaust gas is recirculated by a fluid pressure actuated valve receiving a control signal from a controller which receives and modulates engine induction vacuum to provide a primary source and receives a carburetor throttle-blade controlled suction as a secondary source and compares the primary and secondary sources and discriminates therebetween to provide the lesser as the outward control signal.

Abstract: Engine exhaust gas is recirculated by a fluid pressure actuated valve receiving a control signal from a controller which receives and modulates engine induction vacuum to provide a primary source and receives a carburetor throttle-blade controlled suction as a secondary source and compares the primary and secondary sources and discriminates therebetween to provide the lesser as the outward control signal.

Abstract: A hole type fuel injector with a nozzle body and needle valve having cooperating inner and outer metering rings providing a metering passage (a) to provide an initial reduced rate of fuel injection during an initial increment of valve lift, (b) to maintain fuel pressure at the valve seat to reduce fuel dribble and cavitation erosion during a corresponding last increment of valve closure and (c) to prevent secondary fuel injection.

Abstract: One spring and two spring embodimenls of a fuel injection having a nozzle body and needle valve with cooperating inner and outer metering rings providing a metering passage which (a) meters fuel at a reduced rate during an initial increment of valve lift, (b) assists in maintaining fuel pressure at the valve seat to reduce fuel dribble and cavitation erosion during a corresponding last increment or valve closure and (c) dampens secondary pressure waves to prevent secondary fuel injection.