Abstract: An electromechanical fuel injector for an internal combustion engine. The fuel injector includes a pump unit and a control valve assembly in communication with the pump unit. The control valve assembly including a body and a stator. The fuel injector also includes a stator nut cooperable with the valve body to secure the stator to the valve body and at least one expansion tank to accumulate pressure created by the pump unit. The fuel injector may also include a spacer.

Abstract: A unitary fuel injector and nozzle assembly comprising a high-pressure piston pump and a cylinder body that define a high-pressure fuel pump chamber. An injector nozzle assembly is in fluid communication with the pump chamber and is held in place by a nozzle nut detachably secured to the cylinder body. A nozzle valve assembly includes a spring located in a spring cage within the nozzle nut. A control module is assembled between the cylinder body and the spring cage, the module including a module body having a valve chamber that receives a control valve and a stator assembly as separate and removable elements of the module whereby the stator assembly, the nozzle valve assembly and the control valve can be changed independently of the other elements of the injector to meet various operating requirements.

Abstract: Fluid in a chamber, through which a fuel control armature is moving, is used to dampen armature vibrations. This dampening effect is achieved by forming a passage through which the fluid flows as the actuator moves to a steady state position. This passage may be implemented in a control module for controlling fuel delivery in a fuel injector. The control module includes a control module housing defining the cavity. The armature is disposed at least partially within the cavity. The armature affects the flow of fuel in the injector by changing the area of a fuel port through which fuel passes. The fluid passage is formed as the armature moves towards a contact wall defining the cavity.

Abstract: A nozzle assembly for a fuel injector having a needle valve for controlling an injector valve orifice, the needle valve being subjected to a spring force and a fluid pressure force. The needle valve registers with a fuel delivery orifice and is movable into and out of engagement with a valve seat surrounding the orifice. The needle valve is normally biased to a valve closing position by a spring located in a spring cage. The spring cage becomes pressurized upon movement of the needle valve toward the needle valve open position, whereby a positive pressure is maintained in the spring chamber throughout the fuel injection event. A calibrated bleed orifice allows the spring chamber pressure to decay to a low value between injection events.

Abstract: A honing tool assembly adapted to be chucked in a honing machine for reciprocation and rotation, the assembly comprising a diamond-plated tool for honing cylindrical bores in a workpiece, the diamond-plated tool having a spiral pattern on a cylindrical outer surface, a central bore in the tool adapted to receive a tapered rod engageable with a tapered surface on the central tool opening, the tool being provided with a longitudinal slot that allows the outside diameter of the tool to expand as a force is applied to the tapered rod whereby stock is removed from bore walls of the workpiece with precision roundness and concentricity.

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 fuel injector unit comprises a follower assembly that includes a sleeve having an internal groove that receives a spring clip. The clip is made with a spring ring stock having a diameter less then the width of the groove so that the sleeve may be freely rotated around the retainer clip held in the groove. The retainer clip has linear portions aligned along the flat walls of a follower subassembly that receives a plunger carried by the follower assembly. The flat walls terminate at an expanded shoulder that limits displacement of the retainer clip to a fixed height of the follower assembly for shipping and handling, while permitting controlled axial movement of the follower assembly and the plunger along the aligned flat surfaces of the follower subassembly.

Abstract: A fuel injection nozzle controls the flow of pressurized fluid through a nozzle opening. The fuel pump includes a fuel valve under the control of an electronic engine control module to effect sequential ON/OFF cycles for the fuel valve to establish a pilot fuel delivery pulse through the nozzle followed by a full fuel delivery injection pulse, a damping flow passage in the nozzle, and a flow damping pin in the opening through which fuel flows as the needle valve displaces fuel, the damping pin being biased toward an injection nozzle closed position by a needle valve spring whereby a distinct pilot pulse of fuel is delivered through the nozzle in advance of delivery of a full injection pulse, the valve spring being in a spring chamber that is pressurized to effect a rapid needle valve closure at the end of the fuel delivery pulse.

Abstract: A method for calibrating a fuel injection pump for an engine fuel injection system comprising determining the pressure made available to an injector nozzle at a portion of the injection cycle before the top dead center position of the engine crankshaft. A solenoid-operated control valve establishes a rate of fuel delivery through the injector nozzle. The method calculates a boot current for the valve, which will achieve optimum pressure delivery through the nozzle. An electronic controller for the injection system calibrator relies upon an algorithm to find the lowest and the highest boot current level that will achieve injector stability. The logic of the system will increase the precision of the boot current by repeated substitution of incremental current values to determine an upper limit and a lower limit for the boot current.

Abstract: A pumping system for a fuel injection system includes a body defining a high pressure pumping chamber, a plunger, a high pressure outlet, a high pressure fluid line connecting the pumping chamber to the outlet, a control valve along the fluid line, and a valve and restriction arrangement along the fluid line. The valve and restriction arrangement includes a restriction and a valve body. The valve body is movable between an open position in which fuel flow from the pumping chamber is generally unrestricted by the restriction and a closed position in which fuel flow from the pumping chamber is significantly restricted by the restriction to store energy in the pumping chamber. Advantageously, the high pressure restriction concept may be utilized in a pumping system for various types of rate shaping, including boot injection and square injection, in addition to pilot operation and post injection operations, and others.

Abstract: A pumping system for a fuel injection system includes a body defining a high pressure pumping chamber, a plunger, a high pressure outlet, a high pressure fluid line connecting the pumping chamber to the outlet, a control valve along the fluid line, and a valve and restriction arrangement along the fluid line. The valve and restriction arrangement includes a restriction and a valve body. The valve body is movable between an open position in which fuel flow from the pumping chamber is generally unrestricted by the restriction and a closed position in which fuel flow from the pumping chamber is significantly restricted by the restriction to store energy in the pumping chamber. Advantageously, the high pressure restriction concept may be utilized in a pumping system for various types of rate shaping, including boot injection and square injection, in addition to pilot operation and post injection operations, and others.

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: An apparatus and method of refurbishing a valve seat disposed at a predetermined angle relative to the centerline of an associated valve bore in a workpiece wherein the apparatus includes a support structure on which the workpiece is located such that the centerline of the valve bore is aligned with a known reference axis. The apparatus further includes a tool having a lapping portion corresponding to the valve seat and a drive mechanism for moving the tool along the known reference axis such that the lapping portion is brought into engagement with the valve seat and for rotating the tool relative to the workpiece to lap the valve seat. The method generally includes locating the workpiece in a predetermined position such that the centerline of the valve bore is aligned with the known reference axis and moving the tool having a lapping portion corresponding to the valve seat along the known reference axis such that the lapping portion is brought into engagement with the valve seat.

Abstract: Pumps and injectors having a control valve spring arrangement configured to provide a force step when the control valve is at a rate shape position, and related methods for operating a control valve, are provided. The control valve is moveable over a stroke range between an open position and a closed position. The stroke range includes a rate shape position. The control valve spring arrangement is configured to provide a first spring force when the control valve is between the closed position and the rate shape position, and to provide a second spring force that is less than the first spring force when the control valve is between the rate shape position and the open position.

Abstract: A fuel injector pump for an internal combustion engine including a camshaft-driven fuel delivery plunger, a solenoid valve for controlling transfer of liquid fuel from a fuel plunger cavity to a fuel injector nozzle, and a snubber valve located between the fuel injector nozzle and the plunger whereby unrestricted fuel flow is distributed to the injector nozzle and reverse flow from the nozzle to the plunger chamber is restricted so that cavitation in the fuel delivery passage extending to the nozzle will be avoided and undesirable pressure peaks at the fuel pump are avoided.

Abstract: Pumps and injectors utilize a control valve having a valve body with a valve stem having a step adjacent to the seating surface. The step extends a limited distance away from the seating surface to provide limited pressure relief when the valve body is at an intermediate position that is between the opened and closed positions. Step cross-section and axial length may be configured based on desired hydraulic behavior. In a preferred embodiment, the control valve step is configured for injection rate shaping.

Abstract: A method of utilizing the first valve bounce is used in a diesel engine having a solenoid valve controlled fuel injection system, wherein the solenoid-actuated valve is movable between a fully closed position for injection and a fully open position preventing injection.

Abstract: A control valve assembly for use in a pump or injector of fuel injection systems is provided. A pump or injector body has a pumping chamber, and a valve chamber. The valve chamber defines a valve seat and has an axial guiding portion. A plunger is disposed in the pumping chamber. A valve body disposed in the valve chamber controls fuel. The valve body has a valve stem defining a seating surface. The valve body further has a valve guide in sliding engagement with the valve chamber guiding portion. The valve body is axially movable with respect to the valve chamber over a stroke range. The valve guide has an outer engagement surface that slidingly engages the valve chamber guiding portion with a clearance fit of at least about 5 micrometers in one embodiment. In another embodiment, the axial length of the engagement surface is at most about 7 millimeters. The reduced axial length and/or the clearance fit improve initial sealing performance and sealing performance over the life cycle of the product.

Abstract: A fuel pump or injector has a control valve with a piston valve body axially movable over a motion displacement interval defined by first and second sub-intervals. A first control valve spring causes the piston valve body to be biased toward the unactuated position whenever the piston valve body is in the first sub-interval. A second control valve spring causes the piston valve body to be biased into damped engagement with the valve stop whenever the piston valve body is in the second sub-interval.

Abstract: An armature having a middle beam portion connected to an outer body portion flexes during actuation of the control valve so that movement of the control valve relative to the armature outer body portion is damped as the control valve moves to the actuated position. The armature has at least one slot formed at the interface of the middle beam portion and the outer body portion. The at least one slot is configured to allow the armature to flex.