Internal-combustion engines – Charge forming device – Fuel injection system
Patent
1983-03-03
1986-10-21
Wolfe, W. R.
Internal-combustion engines
Charge forming device
Fuel injection system
123470, 123482, 123510, F02M 4104
Patent
active
046178988
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to an apparatus for supplying appropriate charges of fuel to the working chambers of internal combustion engines.
According to the present invention, there is provided a method of supplying appropriate charges of fuel to a working chamber of an internal combustion engine during induction of changes of air through an adjustable throttle, in which the fuel is passed, in either order, through a variable constriction the flow resistance of which is progressively reduced with increasing throttle opening and through an on-off valve which is cyclically opened for an essentially constant time at a frequency proportional to engine speed.
Also according to the present invention, there is provided apparatus for supplying an appropriate charge of fuel to a working chamber of an internal combustion engine during an intake stage of an operating cycle, the engine having an air intake throttle valve, the apparatus comprising a metering valve operable in response to operation of the throttle to vary the flow area of a variable fuel metering orifice to reduce the flow resistance of the metering orifice progressively with increasing throttle opening, an on/off valve connected in series (in either order) with the metering valve between a fuel source and a delivery nozzle in the intake duct of the working chamber downstream of the throttle, and control means responsive to engine speed for cyclically opening the on/off valve at a frequency proportional to engine speed, the time interval during which the on/off valve is open being essentially independent of engine speed at least under steady load and speed. Preferably an accumulator is included to smooth the supply to the nozzle.
Advantageously, the apparatus includes means responsive to sudden throttle opening to increase temporarily the rate of fuel supply to the nozzle, for example by holding the on/off valve in its "on" position to provide an enriched mixture during the rapid movement of the throttle.
Usually, a richer mixture is required in the lower and uppermost portions of the speed range than in the remainder of the speed range. This can be readily achieved by arranging for the control means to increase the length of the "on" time in each cycle of the on/off valve by an appropriate corrective amount.
Also, the control means may include sensors for measuring one or more other parameters such as ambient and engine temperatures and barometric pressure and include means for carrying out further corrective adjustment of the "on" time in each operating cycle of the "on/off" valve.
All such corrective adjustments to the "on" time, including enrichment for starting, can be effected by a control system, such as a microprocessor, of relatively simple construction since it is only required to make corrective adjustments over a relatively small range, bearing in mind that the large scale "coarse" adjustment is effected by the metering valve. In a preferred arrangement, the control system includes a pulse generator constructed to generate pulses at a frequency proportional to engine speed but of constant length corresponding to a rich mixture, the control system then serving to terminate the pulses by clipping their end portions to give the required fuel delivery. Thus, in the event of failure of the microprocessor or other control system, a vehicle can still be driven although with a rich mixture.
Preferably, for liquid fuel, the nozzle has a capillary fuel delivery tube within an air passage connected to receive unthrottled air, the air passage being convergent around the outlet end of the fuel delivery tube and leading to an outlet in a wall of the inlet passage to the working chamber in a position where each successive charge of air drawn into the combustion chamber will reduce the static pressure and thus draw in air from the nozzle air passage. This in turn reduces the static pressure at the fuel delivery tube outlet and draws off and atomises fuel from the tube. At other stages in the engine cycle, the surface tension of the fuel prevents any sub
REFERENCES:
patent: 3628024 (1971-12-01), Clemochowski
patent: 3656464 (1972-04-01), Hilborn
patent: 3670706 (1972-06-01), Fujisawa
patent: 3734068 (1973-05-01), Reddy
patent: 3949714 (1976-04-01), Mitchell
patent: 4015571 (1977-04-01), Stumpp
Piper FM Limited
Wolfe W. R.
LandOfFree
Fuel delivery to internal combustion engines does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fuel delivery to internal combustion engines, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fuel delivery to internal combustion engines will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1284842