Internal-combustion engines – Charge forming device – Auxiliary air or gas used to inject fuel
Patent
1987-05-18
1989-01-03
Wolfe, Willis R.
Internal-combustion engines
Charge forming device
Auxiliary air or gas used to inject fuel
123459, 123531, F02M 2304, F02M 6702
Patent
active
047949023
DESCRIPTION:
BRIEF SUMMARY
This invention relates to the metering of fuel to an engine particularly in applications where the fuel is injected directly into the combustion chamber of an engine.
There has previously been proposed methods of metering fuel wherein the metered quantity of fuel is displaced from a variable capacity chamber by a charge of gas, such as air, at an appropriate pressure. It is considered that the charge of gas contributes significantly to the efficient combustion of the fuel, at least in part because of improved atomisation of the fuel.
There has been proposed in our International patent application No. PCT/AU85/00176 and U.S. patent application No. 849501 derived therefrom, still pending an improved method of metering fuel to an engine wherein a continuous supply of fuel under pressure is provided to a closed fixed capacity chamber having a selectively openable delivery port. Gas is periodically admitted to the chamber to maintain in the chamber a pressure not greater than the fuel pressure and the delivery port is opened during the period of admission of gas to the chamber, whereby the fuel in the chamber at the time of opening the delivery port, and fuel that enters the chamber during that period is delivered from the delivery port to the engine. This method of metering and delivering fuel is effective, but presents some difficulties in manufacture, particularly high volume commercial manufacture, partly due to the need for substantially simultaneous operation of the valves controlling the discharge port and the supply of gas to the chamber.
It is the object of the present invention to provide an improved method and apparatus for delivering a metered quantity of fuel to an engine that is effective and accurate in operation, convenient to manufacture and maintain, and assists in promoting a high degree of atomisation of the fuel.
With this object in view there is provided a method of metering fuel to an engine having a fuel delivery port and a selectively openable valve element to provide communication to the engine through the port when open, and to provide when the port is closed sealable engagement at two locations spaced in the direction of flow through the port and defining between said locations a cavity, the method comprising supplying fuel and gas independently to the port at respective pressures, one of the fuel and gas being supplied to said cavity and the other being supplied upstream of both sealable engagement locations, cyclically opening the valve element to communicate said port with the engine to permit delivery of fuel entrained in gas to the engine, and regulating the pressure differential between the fuel and the gas at the cavity to control the rate of fuel flow into the gas at the cavity.
When the port is in communication with the engine, the gas establishes a pressure in the port that is less than the fuel pressure so that fuel will flow into the gas as it passes through the port. Accordingly control of the quantity of fuel delivered into the gas may be effected by varying the pressure difference between the gas pressure in the port and the fuel supply pressure. Alternatively the control of the quantity of fuel delivered may be effected by maintaining the above pressure difference steady and varying the duration of the period that the port is open.
Rapidly occuring variations of fuel demand may be accommodated by varying the period that the port is open, while more gradual variations in fuel demand are accommodated by varying the pressure difference between the fuel and gas. The varying of the pressure difference may be achieved by varying the pressure of the fuel supply and/or the pressure of the gas supply. When the fuel is liquid, it is more convenient to regulate the fuel pressure and to maintain the gas pressure substantially constant.
Conveniently the fuel supply pressure may be controlled by a regulator that is responsive to the fuel demand of the engine. The regulator may be electrically actuated under the control of a current determined electronically from sensings of a numbe
REFERENCES:
patent: 1208686 (1916-12-01), Steinbecker
patent: 1627727 (1927-05-01), Charter
patent: 3996906 (1976-12-01), Bubniak et al.
patent: 4167921 (1979-09-01), Steinwart
patent: 4394963 (1983-07-01), Iwata
patent: 4543935 (1985-10-01), Tuckey
patent: 4545354 (1985-10-01), Jaggle et al.
Orbital Engine Company Proprietary Limited
Wolfe Willis R.
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