Abstract: In an electronically operated fuel control valve for a diesel engine, a poppet valve with a stem having a guide surface length portion in a guide bore exposed to a large axial fuel pressure gradient during a fuel injection event, the radial space between the guide surface length portion and the bore being different proximal to a head of the poppet valve than the radial space between such elements distal from the head.

Abstract: In an electronically operated fuel control valve for a diesel engine, a poppet valve with a stem having a guide surface length portion in a guide bore exposed to a large axial fuel pressure gradient during a fuel injection event, the radial space between the guide surface length portion and the bore being different proximal to a head of the poppet valve than the radial space between such elements distal from the head.

Abstract: An electronic unit injector for a diesel engine that has a check valve for maintaining a pressure greater than vapor pressure and being located as close as practical to a plunger chamber to minimize fluid hammer effects on the check valve and has a fuel capture volume below the check valve that is proportioned to store sufficient static energy in compression of the captured fuel to reclose the check valve if opened by fluid hammer action.

Abstract: An electronic unit injector for a diesel engine that has a check valve for maintaining a pressure greater than vapor pressure and being located as close as practical to a plunger chamber to minimize fluid hammer effects on the check valve and has a fuel capture volume below the check valve that is proportioned to store sufficient static energy in compression of the captured fuel to reclose the check valve if opened by fluid hammer action.

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 diesel fuel injector pump comprising a housing having a pump chamber; a piston movable in said pumping chamber to develop a pumping force; a fuel outlet passage communicating with said pumping chamber for delivering pressurized fuel to a fuel injector, a low pressure fuel inlet connected to said pumping chamber; a low pressure fuel return, injection timing means comprising a relief chamber, a control valve having a first position permitting flow from said pumping chamber to said relief chamber, and a second position allowing the entire pumping chamber output to be directed into said fuel outlet passage; a solenoid means for operating said control valve; said solenoid means comprising an armature and an armature chamber; a first accumulator passage connecting said relief chamber to said fuel return; and a second accumulator passage connecting said armature chamber to said fuel inlet.

Abstract: A high-pressure electromagnetic fuel injector having a dual-function valve directly controlled by an electric solenoid. Fuel pressure in a control volume chamber is controlled by the dual-function valve, and a separate control valve is controlled as a function of fuel pressure in the control volume chamber. A spray tip valve is, in turn, controlled as a function of the pressure of fuel controlled by the control valve to inject fuel through a spray tip orifice. The dual-function valve spills fuel during and after the control valve closes, thus reducing the amount of uncontrolled fuel at the end of an injection. The dual-function valve also provides a drain path through which to vent any fuel that leaks past the control valve.

Abstract: A common rail fuel system, primarily including a high-pressure fuel pump, a rail, fuel injection nozzles, and an electronic control system, is disclosed. A substantially constant fuel pressure is maintained within the rail by the fuel pump under the direction of the electronic control system. The pressurized fuel is communicated to the fuel injection nozzles, which are also under the direction of the electronic control system, thereby providing fuel at injection pressure immediately upon the actuation of the fuel injection nozzles by the electronic control system. The pump incorporates leakage fuel during each stroke without the necessity of rerouting the leakage fuel through a primary supply. This reduces the total amount of fuel pumped and improves metering accuracy.

Abstract: A solenoid stator assembly for electronically actuated fuel injectors is disclosed as having an E-shaped stator core including a top portion and three parallel pole pieces extending orthogonally therefrom. The outer pole pieces each have an outermost side, and each of the three pole pieces has a distal end, a face being formed across the distal end. Each of the outer pole pieces has an attachment slot formed across its outermost side proximate its distal end. A coil of electric wire is disposed around an insulating spool disposed on the central pole piece, and leads from the coil are connected to terminals. A flange on one end of the spool exerts outward forces on the outer pole pieces, prestressing them to resist further flexing caused by outwardly directed forces applied by errant fuel under pressure. An insulating cover is molded around the solenoid stator assembly, enveloping it except for portions of the terminals and the faces of the pole pieces, the cover being bonded to at least the stator core.

Abstract: A common rail fuel system is described which consists primarily of a high-pressure fuel pump, nozzles and a rail or rails having a substantially constant rail pressure situated between the fuel pump and the nozzles, the necessary connecting fuel lines and electronic control system. The pump is constructed to add leakage fuel to each stroke output without the necessity for routing this leakage fuel through the primary supply. This reduces the total amount of fuel pumped and improves metering accuracy.

Abstract: An engine valve bridge assembly, or the like, contains an improved lash adjuster assembly including a follower body, such as in a known lash adjuster hydraulic element assembly, in an improved holder that axially separates the mounting portion from the body-carrying bore to avoid distortion of the bore from mounting of the holder. Numerous primary and alternative features are disclosed.

Abstract: A diesel unit fuel injector includes a pump assembly having an externally actuated plunger reciprocable in a bushing which with the plunger defines a pump chamber, with flow therefrom during an injection cycle portion of the pump stroke being directed to a fuel injection nozzle of the assembly. The injection nozzle includes a needle type differential area injection valve that is normally biased to a valve closed position by a valve return spring which is positioned in a spring chamber and which is operatively connected to the opposite end of the injection valve.

Abstract: A fuel injection nozzle is provided with a pressure actuated injection valve with a first spring and a second spring operatively associated therewith to permit two stage opening of the injection valve, these spring also controlling opening movement of a valve during the injection cycle in the mid to higher speed range of engine operation to allow pressurized fuel to act on the stem end of the injection valve to effect its closure at a higher valve closing pressure than the valve closing pressure from idle to a predetermined mid-speed range of engine operation.

Abstract: An electromagnetic unit fuel injector for use in a diesel engine includes a housing with a pump therein defined by an externally actuated plunger reciprocable in a bushing and defining therewith a pump chamber open at one end for the discharge of fuel to a spring biased, pressure actuated fuel injection nozzle. The pump chamber is also connected to a supply/spill chamber via a normally open, hollow, ported valve controlled passage to permit the ingress and egress of fuel, the valve being operated by a solenoid. The stator assembly of the solenoid is fixed to the housing over the supply/spill chamber and has a cover fixed thereto to define an armature chamber for a moveable armature. The solenoid pole piece has a stepped bore therethrough to interconnect the armature chamber and the supply/spill chamber. The armature is operatively connected to the valve by a guide pin slidably and sealingly journaled in a non-magnetic bushing fixed in the stepped bore so that the armature chamber remains dry.

Abstract: An electromagnetic unit fuel injector includes a pump assembly having an external actuated plunger reciprocable in a bushing with flow therefrom during a pump stroke being directed to a fuel injection nozzle of the assembly. Fuel flow from the pump can also flow through a passage means, containing a normally open, substantially pressure-balanced control valve actuated by a solenoid assembly in the valve closing direction to block drain flow during a pump stroke, as desired. A piston, actuated by discharge fuel pressure is operatively connected to the control valve to assist the solenoid in holding the control valve in a closed position.

Abstract: An electromagnetic unit fuel injector for use in a diesel engine includes a housing having a bushing with an externally actuated plunger reciprocable therein to define a pump chamber open at one end for the discharge of fuel to a spring biased, pressure actuated fuel injection nozzle. The pump chamber is connected to a supply/spill chamber means via flow-through solenoid with pivot armature actuated, normally open, hollow pressure sensitive valve to permit the ingress and egress of fuel. The supply/spill chamber means adjacent to the head of the valve is in flow communication with a source of fuel at a relatively low supply pressure.

Abstract: An outwardly opening poppet valve type, fuel injection nozzle is provided with a part or parts thereof electrically insulated relative to the nozzle housing whereby, when the injector poppet valve is closed an electrical circuit can be completed through the injector poppet valve and housing and, when the injector poppet valve is moved to an open position, the continuity of this electrical circuit would be broken. By connecting an electrical continuity tester to this electrical circuit the opening and closing of the injector poppet valve can be detected and can be used to set the timing of a diesel engine.