Abstract: Fuel delivery to an engine from a cyclically pressurizable, electronically controlled accumulator-type fuel injector is controlled by "wasting" at least a portion of the pressurization stroke of the engine's high pressure pump so that a designated portion of the pressurization stroke of the pump does not result in accumulator cavity pressurization. Metering is effected simply by extending the period that the system's existing solenoid vent valve is open into a portion of the succeeding pressurization stroke of the pump so that a portion of the pumped fuel flows directly to vent. Additional electrical load on the engine can be minimized by using a latching type solenoid valve as the vent valve. The metering scheme 1) is more precise than metering schemes heretofore available for injectors of the disclosed type, 2) does not adversely effect injection timing or other injection parameters, 3) and requires no additional hardware.

Abstract: In a two-way utility internal combustion engine, method and apparatus employing an accumulator-type fuel injector having an accumulator cavity and a control cavity both of which are pressurized with fuel to about the same pressure, fuel pressure in the accumulator cavity applying upward force on the needle, and fuel pressure in the control cavity applying opposing downward force on the needle. The accumulator and control cavities are pressurized by means of a reciprocating plunger pump wherein the plunger is driven by cam lobe means on the crankshaft, and injection is initiated by venting fuel from said control cavity through a two-way solenoid valve. Injection mass is varied by variation of the ignition timing relative to pump plunger top dead center. Engine power output is varied between full power and idle by skip-firing, which is caused by noninjection of fuel in the engine cylinder during one or more engine crankshaft cycles during a series of a predetermined number of crankshaft cycles.

Abstract: The present invention is a solenoid-actuated fluid valve of the ball poppet type particularly suitable for use as a fuel injector actuator/timer, for which use the valve must be capable of withstanding high operating speeds and high fluid pressures for a very high cycle life, without substantial internal tolerance variation. According to the invention, the free front end of the solenoid-operated valve actuator pin has a concavity therein which distributes impact loads between the pin and the ball poppet which it engages over an extended line or area contact so as to minimize deformation of the pin and thereby minimize solenoid tolerance variation in the axial direction. Fluid captured between the ball and concavity provides squish-damping as the pin approaches the ball so as to further reduce impact deformation of the pin end. Engagement of the ball in the pin end concavity also tends to hold the ball in axial alignment with its valve seat so as to minimize eccentric wear of the valve seat.

Abstract: An electronically controlled fuel supply system for an internal combustion engine. The timing of the commencement of fuel injection into each combustion chamber is not fixed relative to the rotational position of the camshaft or other engine components. A unit injector assembly associated with each combustion chamber includes a control module and an accumulator type injector module. The control module contains a solenoid valve and, in some embodiments, a hydraulic pressure intensifier. The accumulator type injector module contains an injector nozzle, a hydraulic accumulator, and a non-return valve for admitting liquid fuel under pressure into the accumulator. In operation, an electrical control system supplies an electrical signal to the control module an appreciable portion of the engine cycle in advance of the time when fuel injection is to be initiated in the particular combustion chamber.

Abstract: An electronically controlled fuel supply system for an internal combustion engine. The timing of the commencement of fuel injection into each combustion chamber is not fixed relative to the rotational position of the camshaft or other engine components. A unit injector assembly associated with each combustion chamber includes a control module and an accumulator type injector module. The control module contains a solenoid valve and, in some embodiments, a hydraulic pressure intensifier. The accumulator type injector module contains an injector nozzle, a hydraulic accumulator, and a non-return valve for admitting liquid fuel under pressure into the accumulator. In operation, an electrical control system supplies an electrical signal to the control module an appreciable portion of the engine cycle in advance of the time when fuel injection is to be initiated in the particular combustion chamber.