Note: Descriptions are shown in the official language in which they were submitted.
Field o~ the Invention
The pre~ent invention .relate3 to the engine ~n~ineering,
and more par-ticularly to intornal combu~t:i.on.en~slne ~eed sg-
9 terns.
The system CRn be used Xor feeding petrol en~ines o~
variou~ vehicles.
~ he p:resent invent:ion can be most advantageously used
~or large petxol engines installed on vehioles u,~ed mainly
in bl~ towns. 'I'his is determined by the ~act that one of ad-
vantages of the present ~stem is a marked deorease o~ the ex-
haust-emission toxicitg~
Background o~ the Invention
; It Ls known that the most favourable conditions Xor ig-
niti~ and combustion processos ill spark ignition en~ines
are provided in case the engine cyl.Lnder~ are ~ ed with ho-
mogeneous ~uel-air mixture, i.e, wi-th the [ni~ture wherein the
entire ~uel is in vapour state. In the generaL case, the Xuel
vapour concentration throughout the cylinder volume m.~y be un-
even, the optimum being the concentration field where some mi~-
ture enrichmen~ occurs in the vlcinit-g o~ the spark plug~ How-
ever, to at-tain -tnis field oX concentration ~peci~ll enKine
- designs should be uc~ed (e~g. preco~bu~tioLl chamber cngines),
i~hich lovlers the reliabili-ty o~ internal combusti.on engines and
makec; the:ir rncln~factuce more e~pensiveO '~hece~ore, ~s Rpplied
,. ' ~
~ ~ ~2 ~ ~7
-to convent:Lonal internal combustio~ engirles, optimal conclltior3s
o~ their L7eedinp; .involve compl.etel vaporiza-tion o:L' the iuel ~nd
unieorm mixl'ng oi' the latter with ~lir bef7ore comlJustion star-ts.
The quest f'or decreasin~ exhaust emis,sion to~ici-~y and
raisint~ el'f'iciency O:e petrol enp7:Lnes makes it ~ecessary to de-
velop feeding systerQs v~hich would provide the .-Peedin~ of eng~ine
cyl.inders Wit'rl the homo~7eneous 17uel-air mixtureO
There are a number o~ reasons which make it imperative
-to leed the engine with the homo~eneous mixture, -the most cs-
sential o~ these are as ~ollows:
- decrease ol7 the e~haust emission -toxicity and raisirlg
oi the engine e~iiciency due to increasi~g the limit oi the
e~ficient mi~ture leaning 3
~ providintj a hi~hly e~icient combustion process due to
only the vapour phase oP the luel present in the cylinders;
- reducing the non-unieormity ol the mixture distriblltion
' between cylinders and ~7rom cycle to cyc].e~
~: - loweri~; the engine parts wear due to the outwash oP
oi.l ~rom the cylindcx walls by the unvaporized :euel.
'I'he problem of homop,enizin~7 ~he ~uel~;~ir mi~ture ar~ solv-
ed to a certain extent by ~lll I'eed syste~s now in use, but none
ol them ol717er the complete solution to the problem.
Many attempts have been made aimed at improving para
met~rs oi' petrol eng7ines by intensi~'yinrn7 the ~uel vaporiza-
tion processes, involvir~j the d~velopment Oe various methods
~ ~3~ ~ 5
o.~ inlct p:ipe hea-tin~;, e~g ~ by exhaust g~ases and b~ the ~l.uid
O.e the cooli.n~ s~te~ e~llployed l~ith the carbure-ttor~type L'e~e(l~
in~ hr fue~l deposited a~ a :eilm on the inlr~t pipe ~lall~ is
hea-ted, thu~ raising the degree o~ vaporizationO
~ Io~ever, ~hese systems ~ail to provide khe complete vapo-
rization oI' the f'ucl ~or the ~ollowing reasons:
- ~ormation o~ secondary droplet.s which are broken o~
the ~uel ~ilm ~y the air stream,
inability o~ rel.atively big droplets, which have not
vaporized in the mi~-ture flow when moving throu~h t~e inlet
pipe~ to join the ~ilm~
E~i~orts to raise -the ef~iciency o~ the ~uel vaporization
resulted in the development o~ systems employing t~e inlet
pipe heating. In particular, -there is known an internal com~
e
bustion engina ~eeding system (See "~utombilEng ", 1967, 57,
~o 3, 96-99) comprising an inlet mani~old in parallel with a
small-bore mi~ture ~eed pipe providing a higrl ~low rate o~
the ~uel-air mix-ture and~ hence~ better mixing -thereo~. Be-
sides~ -there i3 provid~3d a heatin~ chamber ~or heatin~, and
dryin~ the liquid ~uel. Respec-tively, two throttle valves are
provided whose interconnecting linkage i~ arranged ~o that
t~le -throttle in the ~mall-bo.re pipe opens be~ore openinp; the
throttle in th~ inlet mani~old.
Durin~ the runnin~-in o~ the engine aeter starting, or
in the cour~e Oe acceleration the ~uel-air mixture is taken
--4
on].y -t,hroup,h thc small-bore pipe where lt i9 6ubjccted to
the interlsive hea-ting b~ exhaust ~ases. At :eu:L.l load the f'uel-
ga3 rnixtu.re pas~e~ t~rough the inlet rnani~old witb.ou-t an~ hea-t-
in~ ~
'rhe in-tenslve heatinp, oil the fuel~air mi~ture i.n -the
inlet pipe results in the thermal. decornposition o~ the :euel
and carbonization on the heating chamber sur~aces that ge-t
heated up to ex~rernely high temperaturesD Besi-les, the heating of
the ~uel-air mi~ture to a high temperature sometlr~es resu].ts
in a spontaneous ig~ition o~ the mixture in the inlet pipe.
~ f~orts to develop .euel vaporization ~eed sys-tems -eree
from the disadvantages mentioned herein~bove lead to employing
vaporizing elements which are heated to somewhat lower tempera-
tures equivalen-t to the boiling temperature o~ the heaviest
petrol LJ~action6. rllhis i6 provided in -the system describcd
in tne U.~.~ Motor mag~zin~l973~ vol~ 14~, No. 368~, 25-
-27~.rrhe system is known to comprise a vaporizing element which
is a vertical pipe, the upper portion thereo~ being located in-
side the .inlet ~ipe~ In the vaporizer thexe is a tube partially
~illed with a volatile liquid which is boiled at the lower end
by hot e~haust gases. 'L'he resul-ta~t vapoux xises to the top
o:f the tube where i.t condenses givin~ up i-ts latent heat o~
vaporization. '~he condensed liquid ealls dowll the -tube walls to
rep~at the cycle. In this way the -vaporizing elemellt is 1t the
cons-tant ter~perature e~ual to the boiling tompe:ra-ture O:e the
volatilo liquid. 'l'he system emplo-ys liqui~ls with the boiling
~.~ 32 ~ S
-temperature o~' abou-t 200C which does not involve the risk
of l,h~ th~rmal ~lecompositlon O:e the ~uel.
IIowevr3r, thc above-descri.bcd system cloes not a~ttain -the
cornplete vapor:i.æati.on of the ~uel~ '~his is accounted for by
the fact that by -the -time the ~uel droplets get uporl the va-
po:rizinp, elernent they contain a comparatively large amount of
li~ht fractions which immediately vaporize as 900n as the drop~
lets hit the highly heated surfRce. As a result, a vapour cu-
shion i~ ~ormed under the droplet which prevents lt from spread- -
ing over th~ sur~ace of -the heatin~ element. In this case, no-t
only a required hea~ con-tact between the llquid fuel and the
vaporizin,P, elemen-t sur~ace ~ails to be o~tained, but also ~a-
vourable conditions are created for driving the droplets away
by the air ~low 5
'Besides, attention should be glven -to the fac-t that both
this ,system and the one described earlier are complex in de
sign.
Also known in the art i~ a feed system ~or in-terna'l com-
bustion en~ine in accordance with the U.S~ Patent No~ 34~1850.
'rhe desi~n of the system is reasonably ~imple. 'rhe Jystem com-
pri.ses an inle-t pipe wit~ a throttle and a ,sur~ace vapor:izing
element containing a heat~supply sec-tion, and a ~ue'l-supply
device connected to a ~uel-me-terln~ devi.ce. 'rhe surface vapo-
ri%inK ele~cnt i~ a plate, o~e.side of which contacts the in-
let pipe wall, thl~ lat-ter bein~ comblned in the place vJlth
3~ ~ 5
~he outlet pipc wall. Thi~ ~ide oi~ the plate i3 -the heat-sup-
ply ~ect-ion~ Opposite the other side o~ the plate, in the in
let plpe wall, there is installed a ~uel Lnjec-tor scrv:ing a~
-the fuel-supply device.
With the engine in operation, the e~haust heat is trans-
~erred to the plate 7 thus heating it to a hi~h temperature. Tile
fuel sprayed by the ~uel injector hits the plate surface and
~aporizes. The ~uel vapours get mi~ed with air and are taken
into the engine cylinder~.
However, the system in question ~ail~ to provide the com-
plete vaporization of the ~uel. ~his is caused by the fact that
the fuel drople-ts, when strikLng the strongly heated .surface
o~ the plate, start vaporizint, ver~ intensively with the result
that a vapour cushion is formed. Sa:Ld vapour cushion prevents
the droplets from spreading over the. plate sur~ace and deterio-
rates the required heat con-tact between the ~uel drople-ts and
the plate sur~ace. Unvaporized ~uel droplets get caught by t'ne
air ~low a~d are t~ken to the ~ngine cylindersO Besides, the
high tempera-ture of the plate oontributes to the thermal de-
composition o~ the ~uel and carbonization on the plate sur~ace.
It ~ollows ~rom the above tha-t none o~ internal combus-
tion en~ine ~eed systems in use today are able to provide the
complete homogenizing of the ~uel-air mixture delivered to the
engine cylinders.
: ~3L32~:~L5
'',
Summary o:~ the Invention
It is a~ objec-t o~ the present :invention to provide an
.interrla] oombu;tion ~nginc :~eed system on~ul~in~ a coMplete
homogenization O:e the ~uel-air mi~ture deliverGd to the en-
gine cylinders during its running in all opera-ting duties, re
sul~ing in a marke~ decrease o~ the exhaust emission to~ici-t~
reduced consurnptiorl o~ fuel 7 as well as the longe~ engine li~e-
time.
~ nother object o~ the present invention is -to increase
a service li~e of the ~eed sys-tem by vir-tue of thè elimination
of the thermal decomposition of the fuel which would otherwise
cause the carbonization on the sur.~ace vaporizing elemen-t.
.
: ~ith these and other objects ln~ view9 there is provided
~ an internal combustio~ engine~eed sys-tem comprising an;inlet
: ~ :
~: ~ pipe fitted with a throttle and with a sur~ace vaporizing
element having a heat-supply section~ and a ~uel-~upply~de-
vice associated wi-th a fuel~metering device, wherein, accord- :
ing -~o the inven~ion, the ~uel-supply device contains a means
adapted ~or delivering the ~uel in the ~orm o~ a film -to -the
.
: surface vaporizing elemént and located at one end -thereo~, ~he
heat-supply SeCtioQ being arranged at itq opposite end.
~ n the ~eed system o~ the presen~ invention the ~uel
is supplie~ in the ~orm o~ the ~ilm to the sur~ace vaporizing
elerrlent at on~ end thereof, while the heating o~ ~he vaporiz-
in~ element i~ per~ormod at the oppo~ite end thereo~. This
-8-
~ ~ ~2 ~'3
rully protect~ the air flow Pa~sing throu~,h tne inle-t pipe
into the engiLle cylinder~ from the unv~porizcd fuel ~rol).Lets
g,etting into it, a ternperature ~ield with a ~radual ter,~peratu-,e
~ e bein~, ~ormed alon~, the~ lenf~;th o~ the suri~ace vaporiYIi.rl~
element as directed ~rorn the ~uel supply area toward the heat-
ed end thereo~. Over th~ entire length ol' the droplet -travel
the temperature varies ~ithin boiling temperatures o~ luel
fractions~ whereby the fuel overheatin~ involv.in~ raising~ the
temperature up -to carbonization tempera-ture,q is rnade impossible~
In this case, the fuel vaporization proceeds at a high 3peed
determin0d by much higher values ol' the vaporizi.ng element to
fuel heat transfer ratio, than usual practice. '~his is achieved
by the fact that the temperature at which each fuel ~racti.on
vaporizes is close to its bolling temperature, -this condition
being automatically maintained in case the op~rating duty is
changed ov~r, t~lUS causin~ a change in -tlle amount of the ~uel
supplied a5 wel~ as in -the exhaust ga~ param~ters.
It i~ dcsirable that th~ mean~ ~OI' deliv~rin~ the ~u~1
in the form o~ the ~ilm to -the sur~ace vaporizing element be
provided a~ an annular chamber ~mbracing -the inlet pipe and
coMrnunicated wlth the interior CaVlty ther00~ -through an annul-
ar slot prov~ded in the inlet pipe wall.
~ his assure6 the uniform spreading o~ t~e ~uel iLl the
~orm of the .~ n upon the ~ur~ace of the vaporizin~ elernent 7
said means bein~ e~tremel~ simplo in de~ign.
~g_
~z~s
: It is a.Lso desirable that the mean,s for deliverinp~
the i'uel in the L'orm o.L' the f'ilm be made as an impell~r ~lo~
~: unted wi~hin the inlet pipe and havinr~ fuel~supply ducts pro-
the
vided in/blades and thc shaiJt -thereoIJ.
'~his prov:ides h.iC,h de~,~ree oi' unii~ormity o.~ spreading~
~: the ~uel in the ~orm of -the filrn over the surfacc o~ the va-
porizin~r eloment, thus makin~, it possible to shorten the len~;th
~: thereoi'~
lt i5 desirable that thc end oi' the suriJace vapori~.ing
element .ith the heat-supply sec-tion located -thereon be pro-
vided with ribs i'or i~creasin,-J the heat-receiving sur~ace there-
o~.
~ his contributes to a more intensive process o~ suppl~-
~ ing heat to thLe sur~ace vapori~ing element 7 thus resultinrr
,~ in a shorter length o~ the heat-supply section~
It is also desirable that the throttle be arranp,ed direct-
~ ly a~ter the end of the sur~ace va~orizing element9 which has
'~ the heat-supply sectlon provided bhereon.
Due to this arrangement the throttle turbulates the lluel-
-~ air mixture, thus resulting in the homo~,eneous compositiorl there--
of acros~ the inlat pipe sectionO
Other objects and advantR~es of th~ inven-tion will be
~pparent ~ro,m the ~ollowinp; detailed description of its e~bo~-
dim~nts when read w:ith t-he accompanyin~ drawin~s, wherein~
~10-
~3;2~
.Brief Descril)-tion ol~ the Urawln~;s
Flp;. 1 :is a s~cti.onal vi.ew scnelllclliica'll~y i.llustratirlg
an internal combustiGn erl~.,ine ~ced s~sterfl accordinfJ to the i.n-
ven-tiorl and tak.en longituclinally alonl, -khe inlet pipe;
~ ip;~ 2 is a sectional view o:.' another embodiment o:~ the
~ internal combustion engine ~'eed s~stem according to -thc inven
- 1-ion -ta'~en lon~,itudinall~J alonpj the inlet pipe, and
~ ig. ~ is an enlarged Vie~lV 0~' an embodiment Oe 1;`ne sur:Eace
vaporizing element.
~: Detailed Description o~' -the Invention
The internal comoustion engine ~eed s~s-tem comprises an
inlet pipe l ~i`i,~, l) :Eitted with a throttle 2 and with a sur~
face vaporiziag element ~. A iuel-suppl~ device 4 is arranged
;
a-t an end 5 o~ the surface vaporizing element ~ and is provided
wit~ electro magnetic i'uel., meterin.~ de~ices 6 as well as a
means 7 adapted ~or delivery the ~uel in the ~o.rm o~ a i'ilm
onto the ~ur~ace vapori~inf~ el~men-t ~J A duct 9 communicates
the electro-magnetic ~uel-rne-terin~ dev.ices 6 with a f'uel pump
lO and a fuel tank ll~ Th~ electro~magnetic fuel-metering de-
vices are controlled b~ a conventional elec-tronic ~uel meterin~,
unit -l~ having its in~)ut connected to engine opera-ting duty
sensors l~. The means 7 i~ an annular chamber 14 embracin~ the
inlot pipe l and comnlunicated with the end 5 O:e the surface
vaporizin~ element ~ throu~i,h arl annulaL slot 15 provic1ed in
-11-
.'~ '
the inlet pipe wall. A heat-supply section 16 i9 located nea-r
an end 17 o:E t~le sur~ace vaporizlnf, clemcnt 3~ which :is or)po-
site -to tlle end 5. 'l~;~haust gases passing through the outl~t
pipe (not shown) p~lve up their latent heat. 'l'he throttle 2
is located directly a~'ter the end 17 oi' the sur~ace vaporizin
elerment 3, IIowever~ the throttle 2 may be positioned beI~ore
the i'uel-supply device 4 a~ well 9 which is indica-ted by the
dash line in the drawing.
Fig, 2 i9 a view o~' another e~mbodiment oi' the,means 7
Ior deliverinO the ~uel in the ~orrn o~ the ~ilrn ~ to -the ~ur-
:eace vaporizinSi element 3. ~aid rneans 7 is an impeller lf3 com-
prisin~ blades 19 Li~ed on a shaIt 20~ The sha~t 20 o~ the im-
peller 1~ is supported in bearings 21 O:e a hub 22 oi' a connect
ing strap 23. The connecting strap 23 is located in the inlet
pipe 1 in such a manner that -the blades 19 o~ -the impeller 18
are on the lev~l. oi~ t~e end 5 of the suri'ace vaporizing ele-
ment 3~ Throu~h ports 24 are provided in the blades 19, tha
ports ~ belng in,cornmunication with l,he electronic Meter-
ing devices 6 via a port 2~ ~acle in -the shai't 20 and ports 26
made in tne connecti.ng strap 23.
~ he heat-supp'l~ .section 16 located at the end 17 o~ the
surIace vaporizing eJement 3 rnay have an eve[l sur~ace ~as suown
in ~igs 1 arld 2)~ But it mcly have ribs 27 (~ . 3) scrving to
.increase the ~eat-rec~ivin~; a~ea oI' the sectiorl 16.
~ hi~ contribute~ -to a rnore .intens.ivc process oi) ~upp'L~
-].2-
3'~
` hcat ~0 t~le surface vat)orizin~ ol~ment ~? tnus resul-tifl,,
in a shol~-er lerli~;-ttl of tlle heat-sup~ se~t:ion 16~ To at-Gairl
thc maximum ~l~'icierlcy o.~ the L)roposed f~ed sys~em the vapo-
rizin~ elemcrlt 3 mu~lj be made.o:~ a hi~h hea-t conductivit~ matc
rial, e.g. copp~:c.
: The proposed i.rl-ternal coMbustion englne feed sy~tcm ope- rates as follows.
With the en~ine in opera-tion, thc fuel ~ig. 1) i3 i'o.~ced
~rom t~e ~uel tan~ 11 to the electro-ma~notic fuel-meterirlg
devices 6 by means of the ~uel pump 10 via the duct 5. 1'he
electro-magne-~ic i'uel~metering devices 6 have their outlets
bein~ in communication with the annular chamber 1~ associ.a-Ged
with -the end 5 of the surface vaporizing element 3 via -the an-
nular slot 15 provided in the wall o~ the inlat pipe 1, At the
same time, due to the throt-tle being open1 t'ne air enters the
i~let pipe 1~ ~he fuel supply control is accomplished by means
o~ var~in~ thc d~ra~ion oi the clrivin~; pul~ses received t'rom
the electronic me-tering unit 12 9 thea shapin~ o~ the sai.d pu.lses
being performed dapanding upon -the .signals ~rom the en~in~ ope-
; - ratin~ dut~ sensors 1~. The metered amount of the ~uel e ~ ers
the annular chamber 14 wherefrom it passes throu~h tha annular
slot 15 to the end 5 o~' t~e sur~ace vaporizing element 3~ and~
bein,, ac-tc~ upon by the air :elow and surface ~tension i'orces ~ ~
spreads over the su:rfacc thereoi~ in the form of thc :eilm 8.
As heat to the surl'ace vaporizing element 3 is supplied on the
section 16 arranged at the end 17 oppo~ ce to the locatiori o"
the means 7, ti~e he~at :rlow f.'rorQ -the heat-suppl~ .~;ectiGn 16
spreads over the sur~ace vaporlzing elemen-c 3 agaln~;t the
spreading o~ the ~uel ~ilm 8~ In this casf3, a buildin~-up
ternperature Lield i5 produced in the surf'ace vaporizin~ el~3-
ment 3 wnich results in heating and vaporizinpj o~' the moving
uel 8 in accordance with the fuel ~ractional distillation
., ~ .
curve. Ac a preset tempe.rature o~ the fue].-supply ~ection 16
of' the suri'ace vapor.izing element 3 each :eraction o~ the ~uel
moving in the eorm of the film 87 being gradually heated, i'i-
nally reaches a zone providing most ~avourable condi~tions for
vaporizing thereo~, i.e~ the zone vJherein the temperature of
the surface vaporizing element 3 is near the boil~ng tempera- -
ture of the eraction in questionO 'rhe wide range temperature
field produced in the sur~ace VapoI~izing element 3, as well
as the rapid increase of the heat-exchange coe~ficient result-
ing ~rom the thinning of the ~uel f'ilm 8 due to spreading and
vaporizing thereo~, automatically provide -the setting-up o~
the vaporizatlon zone for each ~uel ~raction in that very
spot ~,vhere che heat exchan~e conditio~s aIe at their optimum.
There~ore,- no temperature corltrol of the sur~ace vaporizing
elemant 3 is re~uired a~ all operating duties o~ the engine.
'l'he ~uel vapours thus obcained, get ulixed wich the air, ~'nus
.~orming the homogRneows fuel~air mixture of controlled compo-
~ition. 'l'he aIran~emerlt of the throttle 2 in the inlet pipe
,
~3~2~5
1 clirectly aYter the end 1'7 of' the surl'ace vapoLizin,, elernent 3
perYorms trle turbula-tion o~ the l'ucl-air rni~ture Ylovr~ trhus p~o~
ducin~ the homo~,eneous cornposition across -the inlet 1.
'~he in-l,crnal cornbu~tlon engine lJeed s~,stem in accoxdance
with the embodirnent clepictecl in l~i~, 2 operate3 ar, I'olLow~.
~ llitil l,he er~jine in operation, the thro-ttle 2 is open, and
the air Ylo~l passes via tl-le inlet pipe 1 into the engine c~-
linders. In the course o~ its travel the air flow streams over
the blades 19 of -the impeller 1~D thus causing~ the 1~-tter to ro-
tate. The more is the air consumption~ i.e. the rnore open is
the throttle 2, the hi~her is tne rota-tion speed OL the impeller
18, and vice versa. ~-t the same tirne with the air supply the
mctered arrlount of' ~uel is delivered into the enpjine cyiinders
b~ -the electrornagnetic metering devices 6. Via the ducts 26
irl the connecting strap 23, the duct 25 in the si~it 20 o~ the
impeller 18 the ~uel passes into the ducts 2~ OL th~? irrIPe11er
blades 19~ Il'rOm ~he ~ucts 24 trle ~uel Ylows to the end 5 of the
sur~ace VapOriZin~ element 3 and ~preads over i-ts surYace in
trle Yorm oY the l~ilrn 8. The impeller 18 provides a high degree
o~ uniYor[rlity whe?n spreadinpj the Yuel ~ilm 8 over the sur~ce
vaporizin~ elemen-t 3~ thus making it ~osr,i~le to ~horten the
length -therco~ The vaporization o~' the ~uel ~ilm 8 is accom-
plished in a rrlanner similar to that in the err~bodirnent oY the
syst~rrl descrlL?ed above.
'nhile particular eMbodiments oY the invention have been
-15-
~32'~1~
showrl and desc.ribed~ vurious modificat.ions -thereof ~.vill be
apparent to those skilled in t'rle art; aild therei'ore it is
not inten~ed -that the invention be limited to the disclosed
erGbodiments or to tne details ther~of and thc departures ma~
be made there~rom within the spirit and scope of the invention
as defined herein.
~ he present invention prevents the therrnal decomposition
of the ~uel in the process o~ vaporization thereoi' and eliMi
nates the possibili-ty oi' t~le unvaporized f'uel in the li~uic~
phase getting into the engine cylinders~ ~he system p.rovides
the complete vaporization oi' the liquid ~uel and a thorough
rrli~ing -thereof with the air at ~11 operating duties o~ the en-
gine, no special tempera-ture control of the sur~ace vaporiz-
ing element being necessary~ The system provides -the homoge-
neity of the fuel-air mixture entering the engine cylinders
in all operatin~ duties of the engine.
The system provides:
high e~ficiency o~ the i'uel combustion process on ac~
count o~ only the vapour phase o~ the ~uel present in the cy-
linders;
- marXed decrease ol' the exhaust emission to~icity in
all pollutant cornponents thereo~, and improvertlent of the eco-
nomic parameters of the engine;
~ reduction oi' the non-uni~'ormity oi' the ~uel-air mix-
ture het~cen cylin~ers and ~ro~ cycle to cycle~
-16-
~ the decroaso o:E tLle en~!;ine~ p~rts vJear arisinl, î.ru~
ou-t~wash o~ tho oil :~'rom th~ cylinder walls by unva.porized
Puel .
`"'
~'
.~ '
--17--
