Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The present invention relates to a carburetor for an internal com-
bustion engine which is of the type comprising a fuel chamber arranged in the
mixing chamber of a suction tube and rotatable, by means of an impeller wheel
rotating in the induced air current, about the outlet end of a fuel-infeed
conduit disposed in the mixing chamber, and wherein the fuel chamber possess-
es at least one lateral fuel ejection opening for delivering fuel to the
mixing chamber.
Such type of carburetor as described for instance in Canadian
patent specification No. 1,001,020 provides such a well prepared and properly
proportioned fuel-air mixture for all operating conditions of the combustion
engine that the quantity of noxious substances, such as C0 and CH, contained
in the exhaust gases is considerably below the permissible threshold value.
However, measurements undertaken on different ~ehicles of the proportion of
C0 and CH, the engine efficiency and the fuel consumption and extensive check-
ing of the manner of driving a vehicle equipped with such carburetor have
shown that 1aws can still exis~. Typical of these are unsatisfactory idling
performance, undesirable amounts of C0 at low or intermediate rotational
speeds, and insufficient C0 in the full load range where usually it is con-
sidered advantageous to have a C0-content even if of relatively small magni-
tude, and so forth.
The present invention consists in a carburetor for an internal com-
bustion engine, comprising a mixing chamber through which intake air flows,
a fuel-infeed conduit possessing an inlet part fixedly disposed within the
mixing chamber and provided with a fuel inlet opening connectable to a fuel
delivery line leading to a fuel supply outside of the mixing chamber and
possessing a straight outlet part extending coaxially with the mixing chamber
in the direction of the intake air flow and provided at its downstream end
with a fuel outlet opening, a rotor cooperating with the straight outlet part
of the conduit, and an impeller for rotating the rotor about the downstream
end of the straight outlet part of the conduit and about an axis defined by
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the outlet part; the rotor including: a fuel compartment having a bottom
disposed downstream of the fuel outlet opening and extending between the
bottom and the fuel outlet opening of the conduit; at least one lateral fuel
ejection opening disposed from the outlet opening at a distance greater than
an outer diameter of the straight outlet part of the conduit; and fuel flow
channel means or manifold connecting each fuel ejection opening with the fuel
compartment, wherein the fuel flow manifold has between the fuel compartment
and each fuel ejection opening a section extending parallel to the axis of
rotation and wherein an annular gap between the straight outlet part of the
fuel-infeed conduit and an adjacent surface of the rotor is situated and
dimensioned to prevent fuel in the fuel compartment and in the fuel flow
manifold from passing the gap when the rotor is rotating about the axis of
rotation.
In a preferred construction of carburetor the rotor incorporates
a housing having a housing wall, and within the housing there is provided
between the housing wall and the straight outlet part of the fuel-infeed
conduit the annular gap. The length of the annular gap is greater than the
outer diameter of the straight part of the fuel-infeed conduit and the dia-
meter of the uel compartment which is coaxial with the outlet part of the
2Q fuel-infeed conduit is smaller than the external diameter of the outlet part.
At least one tubular fuel flow channel leads laterally away from the fuel
compartment to a fuel ejection opening, the fuel ejection opening being a
metering noz~le for delivering a quantity of fuel which is approximately
proportional to the square root of the fuel pressure in the fuel channel.
In such a construction the diameter of the fuel compartment is
preferably substantially equal to the diameter of the fuel outlet opening of
the fuel-infeed conduit. The tubular fuel flow channel may possess an inter-
mediate section which is parallel to the axis of rotation of the fuel chamber
housing and the diameter of which intermediate section is not greater than
the diameter of the fuel compartment and is greater than the diameter of the
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fuel ejection opening. The tubular fuel flow channel may also include a
starting section which extends from the fuel compartment to the intermediate
section of the fuel flow channel and a terminal or end section which extends
from the intermediate section to the fuel ejection opening. The starting
section and terminal section may each be located in a plane substantially
prependicular to the rotational axis of the fuel chamber housing and prefer-
ably be radially directed. In this respect it is particularly advantageous
if the starting section, the intermediate section and the terminal section
of the fuel flow channel have substantially the same diameter and such dia-
meter is equal to or at most is 10 percent smaller than the diameter of thefuel compartment. In order to atomize fuel ejected from a fuel ejection
opening it is possible to arrange in fr~nt of the fuel ejection opening an
atomizer device, comprising, for example, a spray edge. The provision of
an atomizer device is especially advantageous in those cases where the dia-
meter of the fuel ejection opening needed for the delivery of the required
quantity of fuel is too large to achleve a proper atomization of the fuel.
Generally by providing a single fuel ejection opening there can be realized
optimum preparation of the fuel-air mixture. If, for instance, there are
re~uired for this purpose two fuel ejection openings then the latter are
advantageously arranged at different positions along the fuel chamber housing
and angularly spaced from each other either by 180 or by any other angle.
In order that the invention may be more readily understood, refer-
ence will now be made to the accompanying drawings, in which:-
Figure 1 is a schematic illustration in longitudinal section ofone embodiment of carburetor according to the invention comprising a fuel
chamber rotatable about a fuel-infeed conduit and having fuel ejection open-
ings arranged in communication with the fuel distribution compartment, and
wherein the impeller wheel has been omitted to simplify the illustration;
Figure 2 is a longitudinal sectional view of a second embodiment
of carburetor having a fuel chamber with impeller wheel and having fuel ejec-
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tion openings arranged in communication with the annular fuel flow channel,
Figure 3 is a longitudinal sectional view along the line III-III
of Figure 3a of a third embodiment of carburetor having a fuel chamber where-
in the annular fuel flow channel between the fuel distribution and fuel com-
partments serves for fuel metering;
Figure 3a is a top plan view of the fuel chamber of Figure 3;
Figure 4 is a longitudinal sectional view of a fourth embodiment
of carburetor having a fuel chamber similar to that of Figure 3, however,
having additional tubular fuel flow channels for idling;
Figure 4a is a plan view of the fuel chamber of Figure 4;
Figure 5 is an enlarged fragmentary sectional view of the region
of a fuel chamber encompassing a fuel ejection opening and constituting a
modification of figure l;
Figure 6 is a longitudinal sectional view of a fifth embodiment of
a fuel chamber;
Figure 7 is a schematic illustration of a carburetor according to
the invention including the mixing chamber;
Figure 8 is a longitudinal sectional view through a sixth embodi-
ment of carburetor having a fuel chamber housing with one fuel ejection
opening;
Figure 9 is a longitudinal sectional view through a seventh embodi-
ment of carburetor having a fuel chamber housing with two fuel ejection
openings on opposite sides of the housing axis; and
Figure 10 is a cross-sectional view of a modification of the embodi-
ment of Figure 9 along the line X-X in Figure 9 wherein the fuel chamber
housing has two fuel ejection openings, the angular spacing of which is less
than 180.
Describing now the drawings, firstly it is to be understood that a
fuel-infeed conduit with a coaxial fuel chamber rotating thereabout and an
3Q impeller wheel are arranged in a mixing chamber of the engine between an air
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filter and a control valve or flap.
In the embodiment illustrated in Figure 1 the fuel chamber 2' is
contained in a substantially cylindrical rotor or housing 2 which has a
floor or bottom 2a and which is rotatably mounted adjacent its upper open
end by means of a ball bearing 3 on a straight fuel outlet part 1 of the
fuel-infeed conduit. The straight fuel outlet part, which hereinafter will
be referred to as the fuel-infeed conduit 1, is widened at its outlet opening
la into an enlarged portion 4 which extends close to the inner wall of the
rotor 2 in order to form a substantially annular fuel flow channel 5 between
the fuel-infeed conduit 1 and the rotor 2. The end surface 4b of the enlarg-
ed portion 4 is spaced from the rotor floor 2a, to provide therebetween a
compartment which hereinafter will be referred to as the fuel compartment 6.
The rotor or housing 2 contains an insert member 9 having a trans-
verse wall 9a between the ball bearing 3 and the enlarged portion 4 which
surrounds the fuel-infeed conduit 1 and forms therewith an annular gap 8.
Between the transverse wall 9a and the enlarged portion 4 there is thus
provided in the fuel chamber 2' a further compartment which will be referred
to hereinafter as the manifold or fuel distribution compartment 7. This fuel
distribution compartment 7 thus is in communication via the annular fuel flow
channel S with the fuel compartment 6 and with the mixing chamber via the
annular gap 8 and an opening 11 of the ball bearing 3. The transverse wall
9a i5 adequately spaced from the ball bearing 3 and between both of these
components there is present an aeration compartment 12. No seal is provided
between the fuel-infeed conduit l and the fuel chamber housing 2, so that for
resisting the rotation of the fuel chamber there is only the friction of the
ball bearing. Immediately below the transverse wall 9a there are provided in
the fuel chamber housing 2 a number of fuel ejection openings lO which in the
embodiment of Figure 1 are constituted by radial nozzles having an opening
diameter in the order of tenths of a millimeter. What is important for the
proper operation is that the inner diameter of the annular fuel flow channel
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5 is greater than the outer diameter of the annular gap 8.
It is assumed that the fuel level N lies in the fuel distribution
compartment 7 of the fuel chamber housing 2 when this housing is not rotating.
When the fuel chamber housing 2 begins to rotate then the fuel ascends along
the chamber wall and the fuel surface assumes the configuration of a parabol-
oid of revolution, generally indicated by reference character 13. At high
rotational speeds there is formed in the fuel disLribution compartment 7 a
fuel layer 14 bearing against the inner wall of the compartment~ the thickness
of which is determined by the width of the annular fuel flow channel 5 and
the fuel compartment 6 continually remains filled with fuel. The fuel level
N must be at least such that the lower end of the fuel-infeed conduit 1 is
immersed in the fuel. The supply of fuel into the mixing chamber through the
nozzles 10 is metered as a function of the rotational speed of the fuel
chamber housing 2. It should be readily apparent that with this embodiment
the insert member 9 also can be omitted if the diameter of the piston-shaped
enlarged portion 4 can be made larger than the diameter of the ball bearing
opening ll, in which case the ball bearing opening 11 constitutes the annular
gap.
In the embodimellt illustrated in Figure 2 the fuel ejection openings
2a la are arranged at a distance above the fuel compartment 6 of the fuel chamber
housing 2 which carries an impeller wheel 16. The fuel chamber housing 2 com-
prises at its lower end a cylindrical container 2b, the inner diameter of
which need not be appreciably larger than the outer diameter of the fuel-
infeed conduit 1 which protrudes into the container 2b. Mounted on the con-
tainer 2b are laterally extending small tubes or pipes 15 containing at their
outer ends the fuel ejection openings or nozzles lO. The piston-shaped en-
larged portion 4a of the fuel-infeed conduit 1 is located above the small
tubes or pipes 15. An annular fuel flow channel 5 extends from the fuel com-
partment 6 to the tubes 15 and between the enlarged portion 4a and the inner
3Q wall of the fuel chamber housing to an insert 9 located between the enlarged
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portion 4a and ball bearing 3. The insert 9 serves for forming the annular
gap 8 which can have a very small width.
The aeration compartment 12 is in communication with the mixing
chamber via the annular gap 8 an additional aeration compartment 12' between
insert 9 and ball bearing 3 and the opening 11 in the ball bearing 3. This
embodiment is especially suitable for compact or small carburetor construc-
tions. In this case the fuel level N is located in the fuel compartment 6
between the nozzles 10 and an outlet opening la of the fuel-infeed conduit 1
when the fuel chamber housing is not rotating. With the fuel chamber housing
2 rapidly rotating there is formed in the aeration compartment 12 a layer of
fuel bearing against the wall, and the thickness of this layer is governed
by the width of the section 5' at the annular fuel flow channel 5. The
delivery of fuel into the mixing chamber through the nozzles 10 is again
metered as a function of the rotational speed of the fuel chamber housing 2.
In the embodiment shown in section in Figure 3 and in plan view in
Figure 3a the fuel chamber housing 2 comprises a metallic body or body member
2c having a relatively long central bore 2d. The fuel-infeed conduit 1 ex-
tends almost to the bore base or floor 2e, so that between these two compon-
ents there is a small fuel compartment 6. At a relatively large spacing
from the bore base 2e the metallic body 2c possesses, for instance, four con-
tinuous bores lOb, the outer openings of which constitute the fuel ejection
openings lOa of the fuel chamber housing 2. At the inner end the bores lOb
are for instance conically widened, the conical widened portions forming the
fuel distribution compartment 7 of the fuel chamber. The fuel-infeed conduit
1 from the region of its outlet opening la up to approximately the center of
the radial bores lab possesses a diameter which is only slightly less than
the inner chamber diameter. Hence, the annular fuel flow channel 5a between
the fuel compartment 6 and the fuel distribution compartment 7 has a length
several times its diameter, and the width of the annular fuel flow channel 5a
is smaller than the diameter of the outlet opening la of the fuel-infeed con-
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duit 1. The diameter of the bores lOb is greater than the width of the fuelflow channel 5a. Above the section lb of the fuel-infeed conduit extending
up to the radial bores lOb the fuel-infeed conduit 1 has a somewhat smaller
diameter, so that the annular opening 8' between such tubular portion and
the chamber wall is wider than the annular fuel flow channel 5a. There is
inserted into the opening 8' a socket or sleeve 18 in order to obtain an
annular gap 8, the diameter of which, as previously described, is smaller
than that of the annular fuel flow channel 5a.
The fuel level N should be located slightly above the opening la
of the fuel-infeed conduit 1 when the fuel chamber is not rotating. When
the fuel chamber rotates the fuel ascends out of the lower fuel compartment
6 through the annular fuel flow channel 5a into the fuel distribution com-
partment 7 and at this location is withdrawn outwardly by the centrifugal
force to the fuel ejection openings lOa through the bores lOb and atomized
at the ejection openings lOa. Moreover, air is sucked through the annular
opening 8' and through the annular gap 8 so that there is already delivered
by the ejection openings lOa a fuel-air-mixture into the mixing chamber and
it has been ound that this is very advantageous for the preparation of the
fuel-air mixture. Decisive for the fuel metering are the length and width
of the annular fuel flow channel 5a.
If this carburetor of Figure 3 is dimensioned for particularly low
values of the content of CO- and CH-noxious substances it can happen that
the obtained fuel-air-mixture is too lean for engine idling. Figures 4 and
4a respectively shown in section and plan view an embodiment which overcomes
this defect. The fuel-infeed conduit 1 and the fuel chamber housing 2 with
the bores lOb ~Figure 4a) radially leading away from the fuel distribution
compartment and the lang and narrow annular fuel flow channel 5a are in this
case constructed as in the embodiment of Figure 3. The fuel compartment 6
~Figure 4) is downwardly extended by a, for instance, frusto-conical recess
3Q or depression 6a. Leading from this recess or depression 6a are for instance
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two diametrically opposed tubular fuel flow channels 17 through the metallic
body 2c of the fuel chamber housing to additional fuel ejection openings 17b,
17d, which, in the illustrated fuel chamber, are located at the same height
as the bores lOb. With low rotational speed fuel also reaches the recess or
depression 6a of the lower fuel compartment 6 and from that location flows
through the tubular fuel flow channels 17 to the additional fuel ejection
openings 17b, 17d where it is atomized. In order to meter the additional
fuel delivery the tubular charmel orifice located in the coaxial recess 6a
and connected with channels 17 by a radial channel section 17d or the fuel
ejection opening can be constructed as a nozzle with narrower cross-section,
as illustrated at 17a and 17d. The additional fuel ejection openings 17b,
17d can also be arranged lower than the fuel ejection openings lOa.
As mentioned with the chamber construction of Figure 3 the air
infeed to the fuel which occurs prior to atomization is particularly advan-
tageous. This can also be provided with other constructions of fuel chambers.
Thus, in Figure 5 there is shown on an enlarged scale a fragmentary section
o t~e fuel chamber of Figure l containing the fuel ejection opening or nozzle
10 and where certain modifications will be apparent. Between the ball bearing
3 and the insert member 9 ~here is located the aeration compartment 12 and
below the insert member 9 the fuel distribution compartment 7. The nozzle lO
leads to an enlarged bore 19 in the chamber wall and this bore 19 is connected
by means of an air channel 20 with the aeration compartment 12. With the fuel
compartment rotating the fuel is dispensed out of the nozzle lO and air out
of the air channel 20 into the enlarged bore 19 and at the opening lO'a of
the last-mentioned bore, there occurs a further atomization of the fuel by
the nozzle 10.
With the embodiment shown in longitudinal sectional view in Figure 6
the fuel chamber housing 2 consists of an inner fuel chamber housing 21 and an
outer fuel chamber housing 22. The inner fuel charnber housing 21 is essential-
0 ly constructed as previously described and contains the fuel compartment 6_ 9 _
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into which opens the fuel-infeed conduit 1, the annular gap 8, and the
aeration compartment 12. With the illustrated embodiment the fuel-infeed
conduit 1 is smooth and does not possess any enlarged portion. The aeration
compartment 12 is in the form of a cylindrical hollow compartment or space.
The outer fuel chamber housing 22 surrounding the inner fuel chamber housing
21 forms together therewith the annular fuel flow channel 23 which communi-
cates via lateral bores 25 in the inner ~uel chamber 21 with the fuel com-
partment 6. The outer diameter of this annular fuel flow channel 23 is
greater than the diameter of the fuel compartment 6 in the inner fuel chamber
housing 21. The head portion 22a of the outer fuel chamber housing 22 con-
tains, for instance, four radial bores 24 by means of which the annular fuel
flow channel 23 is connected with the nozzles lO. When the fuel chamber is
not rotating, the fuel level N is located between the outlet opening la of
the fuel-infeed conduit 1 and the nozzles 10. Above the fuel level N it is
possible for radial bores 26 to lead from the aeration compartment 12 of the
inner fuel chamber housing 21 to the annular fuel flow channel 23.
When the fuel chamber housing 2 begins to rotate then the fuel in
the annular fuel flow channel 23, due to its greater diameter, climbs quicker
than in the fuel compartment 6 and by means of the lateral bores 25 in the
inner fuel chamber housing 21 there is realized a pump effect so that fuel
is withdrawn out of the fuel compartment 6 into the fuel flow channel 23.
Equally, fuel can flow through the bores 26 provided as an aid into the fuel
flow channel 23. It has been found that such a construction of the fuel
chamber --which is advantageous in terms of manufacture-- is insensitive to
fluctuations of the fuel level and that also no fuel penetrates through the
annular gap 8.
In Figure 7 there is schematically illustrated a preferred embodi-
ment of the entire carburetor arrangement. A tubular stud or connection 27,
forming a part of the suction conduit of the engine, carries a housing block
28 with the fuel supply for the carburetor. In order to maintain the level
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of the fuel there can be provided a float mechanism which, if necessary can
be constructed such that the fuel level in the fuel chamber only slightly
varies throughout the entire inclination range of the vehicle which arises
in practice. A bushing or sleeve 29 which fits into the tubular stud or
connection 27 carries on, for instance, three radial struts 30 the fuel in-
feed conduit 1 which is coaxial to the bushing and downwardly directed. The
fuel-infeed conduit 1 is equipped with the fuel chamber housing 2 and the
impeller wheel 16. In the simplest case a strut or web 30a is a tubular
element, the inner end of which is connected with the fuel-infeed conduit 1
and at its outer end there is connected by means of a screw connection 31 a
fuel line 32 leading to the fuel supply in the housing block 28. Such con-
struction of the carburetor arrangement allows for a simple accommodation to
different engine models, it only being necessary to dimension differently the
bushing or sleeve 29.
The followng described embodiments are particularly insensitive to
fluctuations o fuel level.
With the ~mbodiment of Pigure 8 a cyclindrical fuel chamber-housing
block 2c, for instance Formecl of aluminum~ contains an axial blindhole bore
2f extending from the top towards the bottom and stepped once in diameter.
The lower portion of such bore which possesses the smaller diameter forms the
uel compartment 6 and the upper portion serves for receiving the fuel-infeed
conduit 1 and has a diameter which is not much greater than the outer diameter
of the fuel-infeed conduit 1. Hence, between the fuel-infeed conduit 1 and
the bore wall 2g there is present an annular gap 8 which has, for instance,
a width of approximately 0.1 millimeter. Pushed onto the fuel chamber-housing
block 2c is a plactics impeller wheel 16 and the entire assembly is supported
in ball bearings 3 for rotation about the fuel-infeed conduit 1 and mounted
by means of radial struts or webs 30 in a tubular stud or connection 27 or
equivalent structure which is inserted in the mixing chamber in the suction
3Q conduit of the combustion engine. The upper part of the bore 2f intended to
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receive the lower end of the fuel-infeed conduit 1 has a depth which is
several times the outer diameter of the fuel-infeed conduit 1. The lower
part or portion of the bore 2f forming the fuel compartment 6 has a diameter
which is equal to the diameter of the fuel outlet opening la. Internally of
the housing block 2c a tubular fuel flow channel 17 leads from the fuel com-
partment 6 to a fuel ejection opening or nozzle 10 located in the housing
block above vanes 16a of the impeller wheel 16. The tubular fuel flow
channel 17 has three sections or portions, namely: a starting section 17e
leading radially away from the fuel compartment 6l an intermediate section
17f which is parallel to the axis of rotation 33 of the housing block 2c,
and an end or terminal section 17g which is radially terminated by the nozzle
10. The individual channel sections 17e, 17f, 17~ are constituted by bores
in the housing block 2c. The nozzle 10 is a metering nozzle which preferably
has the shape of a standard nozzle and the diameter of which governs the
delivered quantity of fuel.
The end section 17~ of the fuel channel 17 is dimensioned such that
the quantity of fuel delivered by the nozzle lO is approximately proportional
to the square root of the fuel pressure at the nozzle inflow. The intermedi-
ate section 17f of the fuel chamlel 17 has a diameter which is not greater
than the diameter of the lower fuel compartment 6 and is greater than the
diameter of the fuel ejection opening of nozzle 10. The diameter of the
radial starting section 17e of the fuel channel 17 is not smaller than the
diameter of the intermediate section 17f of the fuel channel. The starting
section 17e, the intermediate section 17f and the end or terminal section 17g
of the fuel channel 17 can have the same diameter as the lower fuel compart-
ment 6 or their diameter is, for instance, up to 10 percent smaller than the
diameter of the fuel compartment. According to one carburetor model the
different diameters had, by way of example and not limitation, the following
values: Inner diameter of the fuel-infeed conduit l = diameter of the fuel
compartment 6 = diameter of the starting section 17e of the fuel channel
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17 = diameter of the intermediate section 17f thereof = diameter of the end
section 17~ of the fuel channel = 1.6 millimeters; diameter of the fuel
ejection opening 10 = 0.5 millimeters.
For an additional atomization of the fuel-spray jet emanating from
the nozzle 10 the housing block 2c carries an atomizer device 34, preferably
in the form of a spray edge. With the embodiment of Figure 8 the atomizer
device 34 consists of a ring 35, for example, formed integrally with the
impeller wheel 16 and which surrounds at a certain spacing the housing block
2c. The ring spacing and the ring height over the nozzle axis govern the
degree of atomization. The fuel level N is adjusted between the outlet
opening la of the fuel-infeed conduit 1 and the nozzle 10 when the housing
block 2c is not rotating.
When the housing block 2c is placed into rotation by the impeller
wheel 16 then fuel ascends in the tubular fuel channel 17 to the nozzle 10
and is metered by the latter and atomized as fine droplets by the atomization
device 34 and delivered into the mixing chamber. In this connection the
following relationships are present: (a) the rotational speed of the fuel
compartment 6, the tubular fuel channel 17 and the nozzle 10 are approximate-
ly~proport~onal to the quantity of air sucked per unit of time; (b) the fuel
pressure in front of the nozzle 10 owing to the centrifugal force is approxi-
mately proportional to the square of the rotational speed, and (c) the
quantity of fuel delivered by the nozzle 10 per unit of time is approximately
proportional to the square root of said fuel pressure, so that the fuel
quantity delivered per unit of time is always proportional to the quantity
of air sucked-in per unit of time.
Notwithstanding the very simple construction and the relatively
small size --Figure 8 is an enlarged view-- the results which can be obtained
wit~ such a carburetor are surprisingly good. It has been found that the
increase of the C0-content desired with :Eull load is present with increasingly
greater rotational speeds, the greater the spacing a of the axially parallel
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intermediate section 17E of the fuel channel 17 from the rotational axis 33,
so that such CO-increase can be realized without difficulty at a predeter-
mined desired rotational speed.
Figure 9 illustrates a variant of the carburetor arrangement where-
in the fuel chamber-housing block 2c is equipped with two fuel ejection
openings or nozzles 10, 10' arranged on opposite sides of the housing axis.
Leading from the fuel compartment 6 to each nozzle 10 and 10' is a respec-
tive tubular fuel flow channel 17 and 17', which can be constructed like
the fuel flow channel of the embodiment of Figure 8, i.e. both of the fuel
channels 17 and 17' each consist of a radial starting section 17e and 17'e
respectively, an axially parallel intermediate section 17f and 17'f respec-
tively, and a radial end section 17~ and 17'g. One nozzle 10' is closer to
the impeller wheel 16 than the other nozzle 10. In this case the atomizer
or atomization device 34 provided for the atomization of the fuel jet deliv-
ered by the nozzles 10, 10' consists of a cap member 36 placed upon the
housing block 2c and which extends to a point below the nozzle 10' and at the
region of the nozzles 10, 10' possesses a respective section for forming a
spray or spraying edge 37.
Figure 10 illustrates a section through a modification of the car-
buretor of Figure 9 along the line X-X, wherein however the two nozzles 10,
10' are at an angular spacing of less than 180, for instance 90. In
Figure 10 reference character 10 designates the upper nozzle and reference
character 10' the lower nozzle. The cylindrical housing block 2c contains
the fuel compartment 6 from which the tubular fuel flow channels 17, 17' lead
to the nozzles 10, 10'. The housing block 2c carries the impeller wheel 16
with the vanes 16a and the ring-shaped attachment or extension 35 serving for
the atomization of the delivered fuel jet.
It should be readily apparent that the previously described car-
buretors, with essentially the same basic construction, can be readily accom-
modated in different engine models by providing an appropriate number of
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nozzles, construction of the fuel channels and dimensions. In particular
the atomization with an atomizer device can also be omitted if with higher
rotational speeds and smaller nozzle diameter there is realized a satisfac-
tory atomization of the fuel. In order to obtain a small constructional
height or length of the carburetor, it is advantageous to arrange the impel-
ler wheel 16 at the housing block 2c below the nozzle~s). However the impel-
ler wheel can, alternatively, be arranged above the nozzles.
It has been found that also with the lowest content of noxious sub-
stances in the exhaust gases there can be obtained an increased efficiency of
the engine This means that optimization is possible for the content of
noxious substances and engine effîciency, so that subsequent modifications,
which on known carburetors are often carried out to obtain-at the cost of
low content of noxious substances-a better efficiency of the engine are no
longer of interest and can be dispensed with. The carburetor also does not
contain any adjustable adjustment means, so that there i5 also dispensed with
a need for frequent readjustment of the carburetor. A notable advantage~af
the previously described carburetor constructions further resides in the fact
that there is not required an~ accelerator or booster pump.
