Device in carburettors, particularly for internal combustion engines

An atomized fuel-air mixture is obtained in a heartshaped chamber of a rotating member which is mounted in the combustion air inlet duct of an internal combustion engine. Fuel and a gaseous medium are injected into the chamber and are thoroughly mixed by a fuel flow dividing portion formed by the curved walls of the chamber in axial alignment with the fuel injection nozzle, which deflects the fuel flow from the axis of rotation towards the periphery of the chamber. Outlet channels exhaust the fuel-gaseous medium mixture from the chamber and impart a rotational force to the member.

The present invention refers to a device in carburettors, particularly for 
internal combustion engines. 
It has been previously proposed to insert a rotating means in the induction 
duct of an internal combustion engine, e.g. a propeller, to provide 
further fine division of fuel particles which are possibly present in drop 
form. There have also been proposed such solutions where fuel is supplied 
centrally to the hub of a propeller means and by centrifugal force is 
caused to flow out turbulently in the duct carrying the fuel-air mixture. 
Such a solution is very advantageous, especially when idling or slow 
running internal combustion engines. 
With the above-mentioned types of carburettor devices, fine division of the 
fuel indeed does occur, but disadvantages such as an excessive 
cooling-down of the combustion air arise, and also a certain amount of 
flow resistance. Ideal for a fuel-air mixture is that the fuel is supplied 
in as gaseous a state as possible to obtain the most effective combustion 
possible. To achieve this, the fuel drops must already be finely divided 
before entrance into the fuel-air mixing duct, preferably by turbulent 
mixing with a gas. The present invention relates to a solution of the 
problem in question, which, apart from fine division, also provides other 
advantages associated with carburettor technology. 
A device according to the present invention, in carburettors particularly 
for internal combustion engines, consists of a rotatable means inserted in 
a combustion air duct, there being arranged a fuel supply to an inner 
central portion of the means, which is provided with one or more outlet 
ducts, and is mainly characterized by the said inner central portion of 
the means being formed as a chamber with curved wall surfaces, that a 
gaseous medium is arranged for supply to said inner central portion and 
that the gaseous medium and fuel is arranged to follow these walls for 
turbulent mixture with each other before flowing out through the outlet 
ducts, which are so arranged that the means is supplied with a rotation 
force through the effect of reaction. 
The fuel is preferably arranged for supply through a centrally placed jet 
portion substantially orientated in the longitudinal direction of the 
means, and directed towards a flow dividing portion for deflecting along 
curved surfaces merging into curved surfaces adjacent outlet openings for 
the gaseous medium. The rotatable means is suitably provided with 
propeller blades or the like. Further distinguishing features of the 
invention will be apparent from the following description and reference to 
the attached drawings.

The duct 1, carrying air and fuel-air mixture is provided with a venturi 
part 2 in the usual manner, above which there is indicated by chain dotted 
lines an air filter 3 for the combustion air. Air is arranged to flow in 
the direction of the arrow 4. Downstream of the venturi part 2 there is 
mounted a cupshaped strainerlike device 5, which by means of a bearing 6 
centrally carries a propeller means generally denoted by the numeral 17. 
The latter means will be described more closely while referring to FIG. 2. 
A gas or air canal 8 and a fuel canal 9 are led to the propeller means. 
The latter canal is in communication with a fuel flow regulator 10, to 
which fuel is pumped by means of a pump 11. The control means of the fuel 
flow regulator are connected by a shaft 12 carrying a throttle 13 for 
regulating the flow of gas in the duct 1. In the prevailing fashion, the 
shaft 12 is connected to an engine regulating pedal 15, usually called an 
accelerator pedal, by a linkage system represented here by a chain line 
14. The tubular duct 1 is connected downstream of throttle 13, and by a 
flange connection 16, to the induction pipe 17 of an induction manifold 
(not shown) in an internal combustion engine. 
As may be seen from FIG. 2, the ball bearing 6 arranged in the strainer 
means 5 carries a shaft 18 for the propeller means 7. The propeller means 
in its turn consist of two body portions 19,20, together defining a 
chamber 21 with lower curved wall portions 22 associated with body portion 
19 and upper curved wall portions 23 associated with body portion 20. At 
the junction 24 between the body portions there are peripherally arranged, 
at an angle in relation to the radial direction, jet-like outlet openings 
25, opening out through a shell 26 attached to the upper body portion 20 
and stretching down over the cylindrical portions of the lower body 
portion 19. Propeller blades 27 are attached to said shell. 
Through the upper body portion 20 and the shell 26 a hole 28 is made, 
through which an end portion 29 of the pipe 8 extends. Through said end 
portion 29 there centrally extends a portion 30 of the pipe 9 which opens 
out into a jet portion 31. The free end of the pipe portion 29 terminates 
tightly around the jet portion 31 by means of an end plate 32. In said 
pipe portion 29 holes 33 in the cylindrical surface of the pipe are taken 
up adjacent the end plate 32. As is more closely appreciated from FIG. 3, 
the jet portion consists of a spreader means 35 arranged in an end opening 
34, the spreader means being actuated in a direction closing the opening 
34 by means of a helical spring 36. As may be seen from FIG. 3 the means 
35 is conical, as are the engaging wall surfaces in the opening 34. The 
means 35 opens more to a greater or less extent in response to the flow in 
the pipe 9,30. 
The device functions in the following manner. It is assumed that the 
accelerator pedal 15 is actuated so that the throttle 13 assumes an open 
position to allow through an air-fuel mixture from the ducts 1,17 in 
question, the fuel flow through the pipe 9 being hereby increased because 
of flow variation in the regulator 10, caused by said actuation of the 
accelerator pedal 15. Fuel will hereby be forced out through the opening 
34 and spread in the direction of the arrows 37. From FIG. 2 it is 
apparent that the fuel will follow the curve of the wall portion 22. Hot 
air or in appropriate cases, hot exhaust gases by-passed from the engine 
exhaust ducting are pressed through the pipe 8,29. After passing out 
through the holes 33 these hot gases will follow the curve of the wall 
surface 23. The fuel following in the direction of arrows 37 and the hot 
gases following in the direction of arrows 38 will meet each other and 
bring about mixing and vaporization under very high turbulence. Through 
excess pressure in the chamber 21 the hot fuel-gas mixture will be forced 
out through the jet holes 25, whereat the propeller means 7 increases its 
speed of rotation already obtained from the air flow, as a result of the 
reaction effect now arising. The gas flowing out through the holes 25, 
consisting to a major extent of vaporized fuel, mixes with the combustion 
air flowing in the direction of the arrow 4 from the air filter 3 and 
passes hereafter through the strainer means 5 at great speed, past the 
throttle 13 and in through the duct 17 to the valve chambers. By 
conduction from the hot parts of the engine, a certain amount of heat will 
be transferred to the strainer means 5, which thereby also contributes to 
homogenizing the fuel-air mixture passing through the duct formed by the 
ducts 1,17. 
Practical experiments have shown that the gas flowing out through the holes 
25 in the propeller means 7 does not contain any drop-like portions of the 
fuel which was supplied through the pipe 9,30 at all. By means of the 
extremely effective turbulent contact between hot gases and fuel in the 
rapidly revolving chamber 21, the sought-after vaporization of the fuel is 
easily obtained, simultaneously as an extremely effective mixture with the 
combustion air is achieved by rotation of the valve means in the air 
stream. By means of the arrangement shown, a fuel supply is obtained to 
the device which is in proportion to the actuation of the accelerator 
pedal 15, and thus in proportion to the engine power desired to be 
utilized in appropriate cases. It should be pointed out in this connection 
that both the flow regulator 10 and the fuel pump 11 constitute compenents 
known per se, as well as the connection to throttle and accelerator pedal. 
The propeller means which, because of the fuel gases flowing out, will be 
self-driven, will, under certain running conditions, substantially 
function as a compressor for the fuel-gas mixture. This results in that in 
transition, for example, from high revolutions to low revolutions in the 
engine, the kinetic energy of the propeller keeps the rotation going and 
concentrates a certain amount of fuel gas in the ducts to the valves. In 
its turn this causes, during a subsequent acceleration, a high gas 
concentration to be present in said ducts, which efficiently contributes 
to the power increase required during acceleration without liquid fuel 
particles coming into the system, which is usual with current carburettors 
in corresponding acceleration conditions. Extremely favourable and clean 
combustion is thus obtained by the device according to the present 
invention. 
The embodiment shown in FIGS. 4 and 5 is contained in a duct 1 with a 
venturi portion 2 as in the embodiment shown in FIG. 1. In the latter 
figure, for simplicity in demonstration, neither the air cleaner 3 or the 
gas regulation means 10-15 or connecting ducts 16,17 are shown. The air 
from the filter 3 is assumed to flow in the direction of arrow 39 through 
the duct 1 towards the venturi portion 2. The embodiment according to FIG. 
4 comprises a rotatable means 40 which is carried by two pieces 41 and 42 
extending diametrically between the walls of the tubular duct 1. The piece 
41 contains a pipe 43 extending through the wall in the tubular duct 1 and 
the piece to bend downwards out of the piece in the middle thereof and 
into the interior of the rotating means 40. The portion 44 of the pipe 
projecting out of the piece 41 simultaneously constitutes a journalling 
pin for a ball bearing 45, the outer ring of which is attached to the 
rotatable means 40. The portion 44 and the bearing 45 thereby constitute 
one of the mounting points of the rotatable means 40. The other mounting 
point for the rotatable means 40 is situated centrally in the piece 42 and 
consists of a pin 46 coacting with a ball bearing 47, mounted in the 
appropriate end of the rotatable means. 
In the pipe 43 there is arranged a further pipe 48 accompanying the pipe 43 
in its deflection downwards through the portion 44, and terminated by a 
jet 49. As is apparent in FIG. 4 the outer portion 50 of the pipe portion 
44, i.e. the portion opening out into an inner chamber 51 in the rotatable 
means 40, is made tapering. At the end of the tapering portion 50 there is 
an annular opening 52 between the cylindrical surface of the jet 49 and 
the inside surface of the tapering portion 50. In comparing the previous 
embodiment and the present one, it will be found that the pipe 43 
corresponds to the pipe 8, the pipe 48 to the pipe 9 and the jet 49 to the 
jet portion 31. Furthermore, the chamber 51 is shaped substantially as the 
chamber 21 in the embodiment according to FIGS. 1-3. 
Consequently, the pipe 43 is intended to pass hot gases and the pipe 48 to 
pass fuel. Taking into account the shape of the tapering portion 50 of the 
pipe portion 44 the hot gases in this embodiment will flow out around the 
jet 49 and in the same direction as the fuel coming from the jet 49 as 
shown by the arrows 53. Fuel and hot gases are indeed not mixed in 
counterflowing currents, but practical experiments have shown that the 
turbulent mixture will be completely satisfactory even so. The chamber 51 
in the rotatable means 40 is arranged to communicate with the duct 1 by 
outlet pipes 54 attached to the means 40, the pipes 54 being directed 
obliquely outward from the rotatable means 40, as is apparent from FIG. 5, 
so that the fuel gas flowing out provides the rotatable means with a 
rotational movement. The outer ends 55 of the outlet pipes 54 are 
obliquely bevelled to prevent the air flowing in the duct 1 from opposing 
the flow of the gases out of the chamber 51. Adjacent to the bearing 47 
for the rotatable means 40 there are arranged propeller blades 56 with 
such an angular disposition that on rotation of the rotatable means 
through reaction from the gases coming out from the outlet pipe 54 a flow 
direction is obtained for the fuel-air mixture agreeing with the one 
according to the arrow 39. The propeller blades 56 can naturally have a 
counter-directed angular disposition so that on rotation of the means 40 
in the way described above, a turbulent zone is formed about the propeller 
for effectively mixing combustion air and fuel gases. In the 
last-mentioned embodiment, the propeller will serve as a brake to keep the 
speed of the rotating means 40 within reasonable limits for high flow 
speeds in the outgoing fuel gases from the outlet pipes 54. The size of 
the propeller blades 56 can naturally be adjusted in response to desired 
running conditions, so that desired flowng conditions for the fuel-air 
mixture are present. 
To achieve a turbulent zone around the rotating means 40 there is arranged 
above the piece 41 a wreath of guiding fins 57 around the inside wall of 
the duct 1 and the venturi portion 2. It should be noted that said guiding 
fins force the combustion air to circulate in a direction opposite to the 
rotational direction of the means 40 and thereby the direction of the 
propeller blades 56. There is obtained hereby an extremely effective 
turbulent mixture of fuel gases and combustion air, simultaneously as an 
effective speed regulation of the rotatable means is obtained by the 
effect on the propeller blades of the rotating air stream, during high 
flow speeds of the combustion air. 
In FIG. 4 and 5 there is shown an arrangement of the guiding fins upstream 
of the rotatable means 40, but naturally such guiding fins can be arranged 
about the rotatable means or about the propeller portion thereof. 
Within the scope of the present invention it is naturally possible to make 
the devices so that fuel through the pipe 9 or pipe 48 is supplied in a 
way other than by the flow regulating means 10 shown, e.g. via a 
floatcontrolled container similar to what is to be found in current 
carburettor devices. It is naturally not necessary to supply hot air or 
hot gases through the pipe 8 or the pipe 43, but for certain running 
conditions it may be conceivable to supply ordinary air at outside 
temperature through said piping, either directly or via a fan or 
compressor device. The best result is naturally obtained if hot gases such 
as gases bypassed from the engine or heated air are taken to the pipe 43. 
The jet portion 31 or the jet 49 can naturally be made in many different 
ways, but the embodiment shown is extremely suitable in the present case. 
The shape of the chamber 21 and the chamber 51 can naturally diverge from 
what is shown. What is essential, however, is that outflowing fuel and gas 
are mixed with each other in turbulent conditions. It is evident that both 
guiding fins and grooves can be arranged in the inner walls of the 
chambers 21 and 51 to provide further turbulent effect. The direction of 
the channels 25 and the outlet pipes 54 can also be adjusted to current 
running conditions with regard to direction in relation to the flowing 
combustion air, and the dynamic working conditions of the propellers in 
question. In the embodiment according to FIGS. 1-3 it is possible to 
arrange the propeller means on a frame in the pipe 1 and not as shown on a 
dished strainer means 5. The fuel supplied may be a gas. Such a design 
wherein the rotatable means 7 or 40 lack a propeller blade are also 
conceivable.