Fuel injection systems for internal combustion engines
AssigneeLumenition Limited
InventorEric Harold Ford
Life of this patent
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Abstract
The quantity of fuel injected in a fuel injection system of an internal combustion engine is achieved electronically by generating two series of pulses in synchronism with the engine using one series as a reference for maximum advance and the other series to operate a counter to count down the requisite number of pulses beyond the maximum advance point before the fuel injection is initiated, the count of the counter being varied from a computer in accordance with speed and/or load on the engine.
Claims11
An electronic device for controlling the quantity of fuel injected in a fuel injection system of an internal combustion engine in accordance with engine requirements, including means for generating a first series of square-wave voltage pulses in synchronism with the engine revolutions to provide a series of alternate first and second voltage levels;
- means for generating a second sereies of square-wave voltage pulses also in synchronism with the engine revolutions and at a fixed multiple of the first series of square-wave voltage pulses, so that the frequency of the second series of voltage pulses is greatly in excess of the frequency of the first series of voltage pulses;
- means for counting a number of the second series of voltage pulses from a predetermined point in relation to the first series of voltage pulses, the numbeer of said pulses counted depending on the engine requirements;
- means for producing an output at the first voltage level from said counting means after said count has been completed;
- means for detecting the presence of both an output at the first voltage level from the first pulse generating means, and an output at the first level from the counting means, in order to inject a quantity of fuel dependent on the remainder of the count for which there is an output at the first level from the first series of voltage pulses;
- and means for continuously varying the count of the counting means in accordance with the requirements of the engine.
An electronic device for controlling the quantity of fuel injected in a fuel injection system of an internal combustion engine having six cylinders, by a pair of solenoid operated fuel injectors, the injectors operating alternately, and each being associated with three cylinders of the engine, said device including an opaque disc driven in synchronism with the engine;
- a series of equi-spaced slits around the disc;
- a single aperture in the disc;
- two pairs of infra-red radiation sources and two pairs of infra-red radiation detectors arranged on opposite sides of the disc, the first pair being arranged to cooperate with said aperture and second pair with the slits, the elements of each pair being displaced by 180.degree. with respect to one another, the infra-red detectors of the first pair each generating a first series of square-wave voltage pulses in synchronism with the engine revolutions to provide a series of alternate first and second voltage levels;
- infra-red detectors of the second pair each generating a second series of square-wave voltage pulses also in synchronism with the engine revolutions, and at a fixed multiple of the first series of square-wave voltage pulses so that the frequency of the second series of voltage pulses is greatly in excess of the first series;
- a pair of frequency divider circuits for counting the pulses generated from the respective detectors of the second pair of infra-red detectors at a starting point determined when said respective first series of pulses change from the first to the second voltage level;
- a computer for receiving analog information on a pair of inputs regarding the fuel requirements of the engine, and for providing a corresponding digital output in accordance with said analog information to change the count of both frequency dividers, each frequency divider giving an output after the predetermined count, the first series of pulses having previously reverted to the first voltage level before completion of the count;
- a pair of transistorized power stages connected in series with respective solenoids, each power stage being rendered conductive at the instant when there is a first voltage level output from its associated frequency divider and its associated detector of the first pair, whereby the quantity of fuel injected by each fuel injector is precisely monitored in accordance with engine requirements.
Dependencies are inferred from the claim text.