초록 ▼

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

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. In response to that electrical signal, the solenoid valve admits liquid fuel under pressure into the hydraulic pressure intensifier. The output of the intensifier provides a metering and intensifying chamber in which the pressure of the fuel continues to increase until near the time when fuel injection is to commence. As pressure builds up, fuel flows through the non-return valve into the accumulator. Under control of the electrical signal the solenoid valve then shuts off the flow of liquid fuel into the intensifier. The transfer of fuel under high pressure from the intensifier chamber to the accumulator is discontinued due to the non-return valve, and the injector nozzle then fires. Alternatively, the solenoid valve admits liquid fuel under pressure directly through the non-return valve into the accumulator, with the turn-off of the solenoid valve causing the injector nozzle to fire. The control system may be utilized for operating the engine in a modified engine cycle in which firing cycles are selectively eliminated. The control system may also be utilized for controlling different cylinders of an engine differently from each other. The control of engine power is accomplished by either electrical or hydraulic means, or a combination thereof, and does not involve any mechanical adjustments within the unit injector assemblies.

대표청구항 ▼

The method of injecting fuel into a combustion chamber of an internal combustion engine, comprising the steps of: (a) selecting an accumulator type fuel injector having a fuel input, and characterized by the fact that the withdrawal of applied pressure from its input initiates the injection of a fue

The method of injecting fuel into a combustion chamber of an internal combustion engine, comprising the steps of: (a) selecting an accumulator type fuel injector having a fuel input, and characterized by the fact that the withdrawal of applied pressure from its input initiates the injection of a fuel charge; (b) placing said fuel injector in operative relation to the combustion chamber; (c) selecting an electronically controlled three-way valve for selectively admitting fuel into said accumulator type fuel injector; (d) coupling said valve to said injector; (e) coupling a source of liquid diesel fuel to said valve; and (f) whenever it is desired to inject a fuel charge into the combustion chamber, applying an electronic control signal to said valve to open said valve for a selected period of time; whereby at the end of said selected period of time when said valve closes to pressure and opens to vent, said accumulator type injector causes the injection of the fuel charge into the combustion chamber to be initiated; the termination of injection of the fuel charge being controlled by said accumulator type fuel injector and not by said valve or said electronic control signal.