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Патент USA US2404081

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Ju?y i6, 146-
F. c. MOGK
Original Filed Nov. 50, 1938
.2 Sheets-Sheet 1
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Original Filed Nov. 30, 1938
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Patented July 16, 1946
Frank C. Mock and Edward J. Partington, South
Bend, Ind., assignors to Bendix Aviation Cor
poration, South Bend, Ind., a corporation of
Original application November 30, 1938, Serial No.
243,067. Divided and this application October
23, 1942, Serial No. 463,064
4 Claims.
This invention relates to charge forming de
vices and more particularly to discharge nozzles
for carburetors of the pressure feed type dis
clOsed in Frank C. Mock application Serial No.
202,206, ?led April 15, 1938, now Patent No.
2,390,658 issued Dec. 11, 1945. This application
is a division of our ccpending application Serial
No_ 243,067, ?led November 30, 1938, now Patent
No. 2,310,984, granted Feb, 16, 1943.
(Cl. 261-—24)
a throttle l4 operated by a rod l6, Anterior to
the throttle is an air inlet or scoop [8, which
leads to a primary venturi 20 positioned to‘ dis
charge in the vicinity of the throat of a secondary
venturi 22. The primary venturi is provided with
an annular chamber 24 opening into the venturi
substantially at its throat and communicating
through passageway 25 with a control unit here
inafter described. Secondary venturi 22 is pro
A fuel discharge nozzle is used with carburetors 10 vided with an annular chamber 26 which com
of this type to spray the fuel into the air conduit
municates with the air scoop [8 through a plu
leading to the intake ports of the engine. From
rality of tubes 21, and with said control unit
the standpoint of engine performance and oper
through a passageway 28.
ating characteristics it is advantageous to have
Posterior to the throttle I4 is a fuel discharge
the fuel delivered from the nozzle in a ?nely di 15 nozzle, indicated generally at 46, mounted in the
vided or atomized state and uniformly distributed
wall of the air conduit I0 and adapted to receive
into the air ?owing through the co‘nduit.
fuel from the control unit through a conduit 53.
One of the principal objects of the invention is
The control unit casing 63 is divided into ?ve
to provide a discharge nozzle with means for ob
chambers, 64, 65, 66, 61 and 68 by four ?exible
taining more nearly uniform distribution of fuel 20 diaphragms 69, 10, ‘H and ‘12. The diaphragms
into the air stream.
Another object of the invention is to provide
means for obtaining a discharge of ?nely divided
fuel from the nozzle without the use of excessive
are secured at their centers to a control rod 13
by washers ‘l9 and hubs 85 slidably mounted on
said rod and locked in position by tightening nut
14 on the end of rod 13. The nut ‘14 is provided
ly high fuel pressures.
25 with a ball end which slidably engages bearing
A further object of the invention is to provide
recess 15 in the end of casing 3. Control rod 13
a discharge nozzle which will shut off the flow
is connected through two ball type‘ universal
of fuel when the engine is not running but which
joints 62 with a slide valve 16 having ports 11 so
will not act as a restriction to fuel ?ow when
arranged that axial motion of rod 13 regulates‘
the rate of flow is high.
30 the effective area for fuel ?ow from an annular
A further object of the invention is to provide
fuel chamber 18 into the unmetered fuel cham
a discharge nozzle into which air is introduced
ber 68.
and admixed with the fuel ?owing therethrough
Any suitable fuel pump may be used to supply
and the resulting mixture of fuel and air is di
‘ fuel to chamber 18, the one shown at 80 being
rected against a sharp-edged serrated member
of the sliding vane type having a fuel inlet 8|,
whereby the fuel is ?nely atomized.
fuel discharge passage 82 and a by-pass channel
Further objects and advantages of the inven
83 controlled by a pressure responsive valve 84.
tion will be apparent from the following descrip
Unmetered fuel chamber 68 communicates with
tion, taken in connection with the appended
metered fuel chamber 61 through a passageway
drawings in which:
40 86 containing a calibrated metering ori?ce 81.
Figure l is a diagrammatic sectional view of a
Chamber 68 also communicates ‘with chamber 64
device embodying the invention;
through a centrally drilled passage 88 in the con
Figure 2 is an enlarged sectional View of the
trol rod 13. Chamber 6'! communicates with the
discharge nozzle of Figure 1; and
~,discharge nozzle through the passageway 53.
Figure 3 is an enlarged fragmentary view of 45 Chamber 65 communicates through passageway
the discharge nozzle valve shown in Figure 2.
28 with chamber 26 in venturi 22 and is therefore
‘Although the invention is described in connec
subjected to the pressure obtaining in the air
tion with a radial type aircraft engine, it is also
scoop l8. Chamber 66 communicates through
applicable to engines of other types or those used ,_..,passageway 25 with the chamber 24 in the pri
for other purposes.
mary venturi 20 and therefore is subjected to the
With reference to Figure 1, there is shown an
pressure at the throat of said venturi.
induction passage 10 leading to a rotary blower
The differential in pressure between chambers
or supercharger 12 which discharges into an in
65 and 66, created by air ?ow through the con
take manifold I3 of an internal combustion en
‘i-rduit l0, under any given set of operating condi- -'
The induction passage I0 is controlled by 55 tions, will produce a resultant force on the con
trol rod ‘I3 tending to move said rod to the right
ing in a notched or serrated conical tip I38,
in a direction to open valve ports 11. Since the
differential pressure between air scoop and Ven
shown in detail in Figure 3. Fuel under pres
sure is received at the nozzle through passage 53
from the control unit, whence it ?ows into a
turi throat is proportional to the square of the
chamber I54 and through ports I55 into a cham
rate of air flow, the resultant force on the control
ber I53, where it acts on diaphragm I39 causing
rod created by this differential acting on oppo
valve I33 to lift off its seat and allowing fuel to
site sides of a diaphragm of constant area will
discharge past said seat; excessive opening of said
also be proportional to the square of rate of air
‘valve being limited by nut I4I striking the stop
Fuel admitted through ports 11 into chamber 10 559A in the nozzle cap. The vacuum present'in
the air conduit II), at the inlet to the supercharger
68 will ?ow through passage 85, metering ori
and in the vicinity of the discharge nozzle, cou
?ce 81., into chamber 61, and thence through
pled with the effect of Venturi I33A, induces a
passageway 53 to the discharge nozzle 46 from
flow of air through pipe I331, passages I96, I92
whence it is discharged into the air conduit I9
posterior to the throttle valve I4. Flow of fuel 15 and I94, through Venturi I33A and into the con
duit I9. The rapidly moving stream of air and
through the metering ori?ce 81 results in a pres
fuel flowing through the Venturi I33A and strik
sure differential across said ori?ce, which creates
ing the notched conical tip I38 results in the fuel
a resultant force on control rod ‘I3 which acts to
being broken up into very ?ne particles.
the left in a direction to close valve ports ‘I? and
The quantity of .air drawn through the nozzle
thereby tends to oppose the previously mentioned
depends largely upon the differential in pressure
force created by air ?ow through the conduit.
between the air entering the passage I93 and the
Since‘the pressure differential across the meter
pressure at the inlet to the supercharger in the
ing ori?ce 8'! is proportional to the square of the
vicinity of the discharge nozzle. The pressure at
quantity of fuel flow, the resultant force on rod
the supercharger inlet is a minimum when the
‘I3 will also be proportional to the square of the
quantity of fuel ?owing. Thus, for any given
condition of engine speed and load, the control
rod ‘I3 and attached valve ‘It will move to a po
sition such that the force on said rod resulting
throttle is in a closed position and increases to a
value approaching atmospheric pressure as the
throttle is opened wide; therefore, if the passage
I96 is at atmospheric pressure the quantity of air
?owing through the nozzle is maximum when the
throttle is ‘closed, and minimum when the throt
tle is wide open. Since the fuel ?ow is low at
closed throttle and high at wide open throttle,
better atomization of fuel is obtained at part than
at wide open throttle. This arrangement is
from fuel flow will exactly balance the force ap
plied to said rod resulting from air flow. The
squares of the quantities of air and fuel ?owing,
and hence the quantities themselves, are there
fore held in constant proportion to each other,
the absolute value of the ratio depending upon
therefore particularly suitable for use with an en
the relative sizes of the fuel metering ori?ce 81
gine which is operated a large percentage of the
and the venturis 2D, 22 in the induction passage.
time at small throttle openings.
A constant mixture ratio can therefore be ob
By connecting nozzle air inlet I96 to the super
tained throughout the range of air ?ows used
unless otherwise varied by extraneous means such 40 charger outlet I3,'as shown in Figure 1, a differ- '
ent operating characteristic is obtained. Since
as those disclosed in the Mock application above
the nozzle air outlet is at supercharger inlet pres
referred to. One such extraneous means is spring
sure, the quantity of air flowing through the
89, shown in Figure 1 as a weak spring, which
nozzle will depend upon the supercharger rise,
= when the engine is idling, moves valve ‘I6 toward
open position and thus enriches the mixture as 45 that is the differential pressure between super
charger outlet and inlet. Since this differential
is required for idling operation.
pressure increases as the throttle is opened, the
The discharge nozzle 43, as best shown in Fig
quantity of air ?owing through the nozzle will
ure 2, includes a primary nozzle assembly com
be low at closed throttle and high at wide open
prising a discharge nozzle body I32 having a seat
throttle, thereby producing better atomization at
portion I3 I, a valve member I36 secured to a dia
wide throttle openings and hence being well suited
phragm I39 by a washer I40 and locking nut
for use with an engine that is customarily oper
MI, and a nozzle cap I59 enclosing a compres
ated at more nearly wide open throttle position.
sion spring I42 which urges the valve I36 against
the seat I3 I. The assembly is fastened and sealed
While the invention has been described with
in an adapter I90 received in an opening in the 55 particular reference to a particular embodiment
wall of conduit ID by means of a nozzle retain
thereof, it should not be inferred that the in
ing nut I33, packing I34 and gasket I35. Nut
vention is limited thereto or otherwise except in
I33 is formed at its discharge end with a Venturi
accordance with the terms of the following
shaped internal contour as indicated at I33A.
An annular groove I92 is provided in nut I33 60
We claim:
which communicates through a plurality of pas
1. In a fuel nozzle assembly, an elongated hol
sages I94 with the interior of said nut in the
low nozzle body provided with a fuel pressure
vicinity of the entrance of said Venturi shaped
chamber at one extremity and a valve seat at
portion. Annular groove I92 is in communica
its opposite extremity having a discharge port
tion either with the atmosphere, the outlet of 65 therein, a valve member having a body portion
the supercharger, or some other source of air by
slidably received in said nozzle body and a seat
means of a passage I96 and a pipe I91. The
portion adapted to engage said seat, a member
chamber I58 within the cap I59 is vented through
having a Venturi-shaped fuel discharge passage
port I6I either to atmosphere or to the pressure
in substantially axial alignment with and spaced
at the Venturi annulus 24, the latter arrangement 70 from said discharge port, said valve member hav—
being particularly described and claimed in our
ing an elongated extension projecting through
above mentioned joint application Serial No.
said passage and terminating in an enlarged tip
243,067, of which this application is a division.
‘ against which fuel is discharged to effect atomiza
Valve I39 is formed with an extension I3‘! pro
tion thereof, and means for conducting air under
jecting through the .venturi I33A and terminat .75 pressure to the space anterior to said Venturi
shaped discharge passage for admixture of air
with the fuel as the latter is discharged from said
port through said passage against said tip.
2. In a fuel nozzle assembly, an elongated hol
low nozzle body provided with a fuel pressure
chamber at one extremity and a valve seat at its
opposite extremity having a discharge port there
in, a valve member having a body portion slid
ably received in said nozzle body and a seat por
tion adapted to engage said valve seat, an adapter .
assembly mounting said nozzle body including a
member having a Venturi-shaped fuel discharge
passage in substantially axial alignment with
and spaced from said discharge port, said valve
member having an elongated stem projecting
from the seat portion thereof through said pas
ed to discharge into the intake manifold, a fuel
nozzle positioned to discharge atomized fuel into
the induction passage between the throttle and
the supercharger, means including a conduit for
supplying fuel under pressure to the nozzle, a
valve in said conduit, means responsive to pres
sure of the fuel for controlling said valve, and a
conduit leading from the intake manifold to the
nozzle for admixing atomizing air with the fuel
prior to its discharge from the nozzle, whereby
the quantity of atomizing air admitted to the
nozzle is in direct relation to charging pressure.
4. In a charge forming device, an induction
passage, a throttle controlling the same, a super
charger in the passage posterior to the throttle,
a fuel nozzle positioned to discharge into the in
sage and terminating in an enlarged conical tip
duction passage between the throttle and super
against which fuel is discharged to effect atomiza
charger, said nozzle having a fuel duct therein
tion, said tip when the valve member is seated
terminating in a fuel discharge ori?ce, means
lying beyond the restricted portion of said passage
for supplying fuel under pressure to the nozzle, a
and approaching said restricted, portion as the
pressure responsive valve controlling the duct,
valve member is moved clear of its seat, and
and a conduit for transmitting atomizing air to
means for conducting air under pressure to the
the nozzle connecting the passage in the region
space anterior to said Venturi-shaped discharge
of the outlet of the supercharger to the duct be
passage for admixture of air with the fuel as the .25 tween the valve and the ori?ce, whereby the
latter is discharged from said port through said
quantity of air ?owing through the nozzle is in
passage against said tip.
direct relation to the pressure rise across the
3. In a charge forming device, an induction pas
sage terminating in an intake manifold, a throttle
controlling said passage, a supercharger in the 30
induction passage posterior to the throttle adapt
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