Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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r
This invention relates to a method for the preparation of an air-
fuel ml~ture particularly in internal combustion engines with spark igni~ion.
There are many methods known and used in the art of atomization of
liquid fuels by means of high-velocity gas to feed internal cc~rbustion engines
with spark ignition.
The most popular method for atomization of fuel is a venturi tube
used in a carburetor, less popular being carburetors with an adjustable ven-
turi. There are also modern methods used which aim at improvement of fuel
feed svstems, these modern methods including: atomization in a sonic Dres- -
serator carburetor with adjustable venturi, atomizatio~ in sonic-type idle-
run nozzle developed by the Ford ~lotor Company, Autotronics Induction System
used by the Jet Propulsion Laboratory - California Institute of Iechnology,
atomization in sonic nozzles manufactured by the Mcdular Sonics Corporation
and by the Sonic Development Corporation of America and used in modified ver-
sions by the Olson Engineering Cc~npany, and fuel injection systems with air
delivered to the injector, these systems being clevelo~ed by Deutsche Vergaser
Gesellschaft and also by Tecalemit-Jackson.
~lawever, none of the prior art methods uses a principle on which the
method of this invention is based.
The imperfection of methods known in the art is either due to the
highly cc~nplicated equipment itself for atomization of fuel, particularly
complicated being the systems to control the ratio and the rate oE air-Euel
mixture, or due to insuEficiently good atcmization of fuel and poor precision
in control oE the ~txture in view of the hic~h r~quirements which nxxl~n en-
gines have to meet as rcc~ard~ the cl~c~nness ~ncl ~ficl~ncy oE cx~bustion.
The present invention is directed to developing a method ;Eor quantita-
tively and clualitatively precise mLxture control~ the novel method securing
suitable atc~mizatic)n and hom~genity of mixture by means of a sumple cand rela~
tively cheap apparatus.
3Q According to one aspect of the present inVention there is provided
a method Eor preparation of an air-Euel muxture by fuel ato~ization using a
high~velocity gas as an atomizing agent~ wherein the fuel is continuously
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induced by means o~ said gas under pressure higher than ambient pressure,
the amount of induced fuel being proportional to the pressure of said gas, `~
said pressure being at least partially controllea by engine speed and load,
so that in the range o~ eng me full loads a mixture ratio giving a maximum
effective pressure is obtained and in the range of engme partial loads, .
a mixture ratio giving at least one of a m mimum consumption of fuel,
and a minimum of toxic components in exhaust gases is obtained said fuel
being continuously atomized and homogenized, a mixture thus prepared being
introduced to an engine inlet manifold upstream of a throttle, said mixture ~ ;
mixing in said inlet manifold with gas induoe d by the engine to charge the
engine cylinders, while under engine coasting conditions when the ~raking :effect of the engine is utilized and the throttle is closed a pressure ~:
difference is utilized to cease delivery of compressed gas to the atomizer ` and to interrupt the admission of fuel.
According to another aspect of the present invention the.re is
provided an apparatus for preparation d an air-fuel mixture comprising a
multi-stage atomizer consisting of a series of nozzles o~ vario~ls shapes,
sizes, stages and directions of operation and of fuel and communicating
passages, said atomizer constituting a self-contained element installable
in an inlet manifold of an internal cambustion engine upstream of a throttle
and being connected, through a passage with a float chamber for containing
fuel, and through a gas passageway with a conditioning and control svstem
for supplying gas under pressure higher than ambient pressure to said
atomizer 5aid c~tomiæer being tipped with a di~Euser opening towards the
engine inlet manifold above the throttle where the mixture is mixed with
induced air to produoe. charges for the en~ine cylinders, said conditioning
and control sy~tem including a pump hc~ving a governor to control a release
valv~.
The condikioning and control system may further include a
compensation and control reservoir connected with said pump and said
gove mor, said gas passageway h~ving a deliver~ rate thr~ttle installed
therein said rate khrottle being pneumatically coupled with the pressure
existing downstream of the throttle and being mechanically linked with an
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accelerator pedal tandem with the throttle, and a passage for idle-run of the
engine.
The throttle of the apparatus preferably consists of symmetrically
opening elements, the shape of the said elements being suited to the shape
o cross-section of the engine intake manifold. An idle-run atomizer can be ~;~
installed in this throttle, said atomizer operating only when the throttle
is closed and consisting of a Laval nozzle located in the axis of mixture
flow, a port co-axially located under the Laval nozzle being used with
another suitably staged nozzle, said latter nozzle expanding the homogenized
and atomized mixture under the throttle.
The float chamber may have a conventional vent hole, said vent hole
being connected with the engine intake manifold space
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above the throttle, or preferably the said chamber being connected, through a
passage, with the passage through which the compressed gas is delivered to the
atomizer, this arrangement securing a suitably controlled delivery of ~uel
irrespective of ~uel induced by the atomizer jets.
The conditioning and control system of the invented apparatus in-
cludes a gas delivery unit, said unit preferably consituting a displacement
pump coupled with the engine crankshaft and having preferably a centrifugal
governor mounted on the pump shaft. The governor controls a release valve or
a pressure reducing valve. The system also includes a unit controlling the
conditioning syste~ and regulating the gas pressure, in accordance with engine
speed and load, by means of a compensation and control reservoir with passages
connecting the said reservoir with the atomizer, by means of a rate throttle,
said rate throttle being pneumatically coupled with the pressure existing
below the engine throttle and being mechanically linked with the accolerator
pedal tandem with the engine throttle. In an alternative arrangement, the
conditioning system is controlled by means of the rate valve connected with
the passage or compressed gas and with the atomizer, said rate valve being
controlled either by a pneumatic actuator responding to the pressure existing
below the throttle or being mechanically controlled by the accelerator pedal
tandem with the throttle. Within the range of dynamic control of mixture
ratio. In an alternative arrangement said conditioning systcm is controlled
by an electronic control system where the basic input values ~or the said
oloctronic control systom aro: engLno spoed, posltion oE tho nccolorator
pedal and the mass of air charge induced by the engine: the auxiliary input
values for the said electronic system being: for instance temperature and
humidity of inducod air, and enginc temperature.
Thus, the novel method and apparatus has a quantitative and qualita-
tive precision in the control of air-fuel ratio, and good atomization and homo~
genity of mixture is obtained thus causing the combustion process to be com-
plete with a considerable excess of air, the volumetric efficiency of cylinder
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~lso beingimproved. In consequence a higher economy in fuel consumption is
achieved, the contents of toxic constituents in exhaust gases is reduced, and
the overall performance of the engine is improved (i.e. the power and the
torque of the engine). The invented apparatus is also relatively simple in
construction and in production.
An embodiment o~ ~he invention will now be described by way of ex~
ample and with reference to the accompanying drawing in which:
Figure 1 illustrates the novel apparatus diagramatically;
Figure 2 illustrates an idle-run atomizer of the apparatus;
Figure 3 illustrates in longitudinal section an alternative embodi-
ment of the apparatus; `
Figure 4 illustrates in longitudinal section, the apparatus with an
atomizer in the alternative embodiment;
Figure 5 i}lustrates the apparatus as viewed from the top and with
rate valve illustrated in section;
Figure 6 illustrates in section the atomizer in the alternatlve em-
bodiment; and
~igure 7 illustrates in section the alternative embodiment of the
atomizer supplied from two sources of gas.
As illustrated in the drawings, the novel apparatus alternatively
includes an atomizer 1 ~Figure 1), an atomizer 2 ~Figures 3, 6), or an atomizer
3 ~Figures ~,7), said atomizer being installed in the intake maniEold ~ of the
engine before a throttle 5 (~igure 1) or beEore fl throttle 6 ~igures 3,4),
and boing connected with a eloat chamber 8 by means oE a Euol upply passnge
7, and with a conditioning and control system by means of a passage 9, through
which the air or other gas under pressure higher than the ambient pressure,
e.g. exhaust gases is being supplied.
The pressure of gas supplied through passage 9 is obtained by con-
ventional methods and is principally controlled by the engine speed and load,
said pressure determining at a particular moment the rate of delivered fuel,
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and acting at the same time as an agent to atomi~e fuel and to homogenize the
mixture in successive stages of atomizer 1l 2, 3. The atomizer is tipped with
a diffuser 10, said difuser expanding the mixture into the intake manifold
4 of the engine above of the throttle 5, 6, where the mixture is mixed with
air induced by the engine, said mixture then 10wing into the engine cylinders.
The multi-stage atomizer 1, or 2J or 3, of the novel apparatus con-
sists of a series of nozzles of various shape, size, stages and directions of
operation, and includes the fuel supply passages, said atomizer preferably
constituting a self-contained element causing the fuel to be several times
more thoroughly atomized and homogenized due to various velocities and flow
directions of streams of gas. Certain stages of the atomizer can be supplied
with gas under pressure which is controlled as described above, and other
stages can be supplied with gas of pressure determined by other parameters;
e.g. one or two stages of atomizer 3 are connected with passage 11 through
which the exhaust gases are delivered from the exhaust system.
In the idle-run of the engine when the engine throttle 5, or pre-
eerably throttle 6, is closed, tsaid throttle 6 consisting of symmetrically
opening elements whose shape is suited to the shape of the cross-section of
the engine intake manifold), and when the fuel delivery rate is small and the
atomization poor, the high difference of pressures which exists above and
below of throttle 5, 6 can success~ully be used to homogenize the m:ixturo
furthor by causing its previously separatod high-velocity streams to collide
and expand -ln an idl~-run atom:izor 12. Tho idlo-run atomlzer consis~ing Oe a
Laval nozzlo, a port situated co-axially under tho Laval nozzle, and another
nozzle, said latter nozzle being suitably staged and expanding the homogenized
and atomized mixture below o~ the throttle 5, 6.
As illustrated in ~igure 1 the float chamber 8 has a conventional
vent hole, said vent hole being connected with the engine intake maniold 4,
namely with the space of said manifold above of the throttle, or preferably
the said chamber being connected, through a passage 13, with passage 9 as it
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is shown in Figure 3 and in Figure 4. This provides an advantageous control
of fuel delivery to the atomizer nozzles simultaneously with fuel induction.
lhe conditioning and control system of the apparatus includes a gas
delivery unit, said unit pre~erably constituting a displacement pump 14 coupled
with the engine crankshaft and having preferably a centrifugal governor 15
mounted on the pump shaft, said governor controlling a release valve 16 or of -
a pressure reducing valve. The conditioning and control system further in- `
cludes a control unit regulating the pressure of gas delivered above the
atomizer 1, 2, 3 in accordance with the engine speed and load and in accordance
with other additional parameters.
In an alternative version shown in Figure l the control system of
the novel apparatus includes a compensating and control reservoir 17, a passage
9 with a rate throttle installed inside which is pneumatically coupled with the
pressure existing below the throttle 5 and mechanically linked with accelerator
pedal tandem with the throttle 5, and an idle-run passage 19,
said components operating so that in the idle-run, when throttles 5, 18 are
closedJ the gas flows only through the passage 19. At partial loads of the
engine the gas flows through the passage 9 in a rate in accordance with partial
opening of throttle 5 and in accordance with partial opening of the rate
throttle 18. At the full load of the engine enrichment of mixture is dynami-
cally controlled, at a fully open throttle 5, by further opening the rate
throttle 18. In a coasting condition when the braking o~ecct Oe the engine is
used, ~he throttles 5, 18 and the idle-run passage 19 Oe the ongine nre closed.
In an altornatlvo ombodiment shown ln ~iguros 3, ~, and 5 the control
system includes a delivery rate valve 20 installed in the passage 9 and con-
trolled by a pneumatic actuator 21 by the value of pressure existing below the
throttloJ snid rato valve 20 being also mechanically controlled by the accele-
rator pedal tandem with throttle 5, 6. The control system operates so that,
in coasting the delivery rate valve 20 is fully closed, in the idle-run only
the port is open as required, at partial load o~ the engine the delivery rate
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valve 20 opens in the function of pressure existing below of the throttle 5,
6, said function depending on the engine speed and load, and at full load of
the engine enrichment of the mixture is dynamically controlled, at throttle
5J 6 fully open, by the delivery rate valve 20 being further opened mechanical- :
ly by stepping on the accelerator pedal until the said valve is fully open.
In yet an alternative embodiment of the novel apparatus the pressure ~
of gas delivered to the atomizer 1, 2, 3 is controlled by means of an electro- ;
nic system directly controlling the pressure and the delivery rate of pump or
of pressure reducing in accordance with an output signal determined by the in
values and data such as the engine speed, the position of accelerator pedal,
the mass of charge induced by the engine, the temperature and the humidity of
air induced by the engine, and the engine temperature.
