US2121506A - Carburetor - Google Patents

Description

2 Sheets-Sheet 1 /n ven or Marcelouz'sMemeSsan M. MENNESSON CARBURETOR Filed Dec. 9, 1955 June 21, l193s.

JuneZl, 1938. .M MENNESSON 2,121,506

CARBURETOR Filed Dec. 9,\ 1935 2 Sheets-Sheet 2 15 In venian.' Marllouisemesson Patented June 2l, 1938 CARBURETOR Marcel Mennesson, Neuilly-sur-Seine, France;

assgnor to Societe Anonyme Solex, Neuillysur-Seine, France, a corporation of France Application December 9, 1935, Serial No. 53,682

In Belgium January 29, 1935 8 Claims.

particularly concerned with those fdr; aircraft' engines. l

The main object is to produce a carburetor which can operate in all positions to which the engine to which it is tted is brought, even in the case where the carburetor is turned through 180 from its normal position.

A oatless carburetor according to the present invention comprises a space communicating with the suction pipe of the engine by means of at least one passage whose effective section is relatively small and with the free air by means of at least one passage whose section is relatively large so that the pressure in said space is practically independent of the suction prevailing in said suction pipe and in which space the primary mixture of fuel and air is effected, fuel being fed to said space from a fuel pump, means for controlling the feed of fuel into said space, a throttling member for air or mixture in said suction pipe of the engine, and a rigid connection between said throttling member and the fuel controlling means.

A further feature consists in providing feed regulating members of carburetors of the kind in question with means adapted to prevent a sudden opening of the said members and, on the contrary, to impose on this opening a period which corresponds substantially to the period of accelerationof the engine.

Another feature consists in embodying in carbu retors of the kind in question, means, independent of the quantity of air admitted in the carburetor and adapted to correct the richness of the mixture, by varying the discharge pressure of the fuel pump, said means being actuated manually or automatically as a function of the momentary conditions of working such as the quantity of mixture to be fed to the engine or the temperature, density or pressure of atmospheric air, considered separately or together. i

In order that the nature of the invention may be more clearly understood, reference will now be made to the accompanying drawings.

Fig. 1 shows, in vertical diagrammatic section, a carburetor constructed according to a rst embodiment of the invention.

Fig. 2 shows, similarly, a carburetor constructed according to a second embodiment of the invention.

Fig. 3 shows, in elevation (parts in section) an alternative of a part of the embodiment according .to Fig.'2.

In the different embodiments represented there is arranged, outside the suction pipe I of the engine, a space or chamber 2 which is advantageously given-a spherical form and of which the wall is supported by suitable means. Into this chamber there opens, near its central part, an air conduit 3 the section of which may be adjustable or not, as desired, and which opens into the free air, for example by being connected to the said suction pipe in front of the throttling member-suchfas the butterfly valve ll--which regulates, as in the ordinary way, the degree of opening of the said suction pipe I and consequently the feed of combustible mixture to the engine, by the intermediary of the means described below.

On the attached drawings there is shown, by way of example, an air conduit 3 in the form of a tube of relatively great transverse section and of which the greatest part is substantially parallel to the axis of the suction pipe I. Further, the axis of the air pipe is offset somewhat beyond the theoretical centre of the said chamber 2.

In the chamber I there also opens a conduit 5 for the feed of fuel in such a Way that the outlet orifice of the said conduit is not-located opposite the air conduit 3, the outflow of fuel being effected for example parallel and in the opposite direction to the feed of air furnishedby the conduit 3. In this way the two fluid currents (fuel and air) do not encounter each other. It follows that, on the contrary, the whole of the fuel is effectively fed to the interior of the chamber 2 and cannot enter the conduit 3 whatever the positioning of the conduits 3 and 4 relatively to the vertical during flying and even when the aircraft is inverted. Further, by reason of the opposite directions in which these two fluid currents enter the chamber 2, the regular and homogeneous mixing of the fuel and of the air is facilitated.

'I'he said chamber 2 communicates by passages 6 (orifices or pipes) of relatively small section and more or less regularly distributed over the whole of the surface of the wall of the said chamber 2, with a space l closed to the outer air and which surrounds the said chamber completely` It follows that whatever the position of the carburetor in space, the mixture formed in the chamber 2 can enter the space l by the whole or by certain of the said passages 6.

The said space `I communicates with a pipe il which feeds the mixture entering the said space I into the suction pipe I of the engine beyond (or in front of) the throttling member 4.

'Ihe sections of the passages or orifices 6 and 'that of the air pipe 3 have, advantageously, such relative values that the suction effect of the engine, acting in the chamber 2 by means of the orifices 6, has a substantially zero value on the 'g` feed of the outlet orifice I of the fuel pipe 5,

so that the pressure in said chamber 2 is practically independent of that prevailing in suction pipe I.

The feed of fuel is effected by a head or a pressure, for example by means of a fuel pump drawing the fuel from the reservoir and discharging it-preferably by means of an arrangement adapted to regulate its discharge pressure and which will be described below-into feed pipe of which the outlet I0 in the chamber 2 is controlled by a closure device such as a needle I I connected by a suitable transmission I2 to the control mechanism I3 for the principal throttling member 4. The arrangement is such that the opening and closing of the members I I and 4 is effected simultaneously and according to suitable proportions. r

In order to prevent an excess of fuel by a sudden action on the control I3 when opening the carburetor, it is of value to limit the speed of opening of the said members II and 4 in such a way as to permit the engine to accelerate before this opening becomes complete.

The rapidity of thisv opening could be limited by a device having a damping action on control I 3. One of the movable members of this control I3, such as the rod I4 of the needle Il, may be retarded by a dash-pot I5 which does not permit a rapid operation of the control I3 in the direction of opening but, on the conf be constituted by an expansion device with a di.

aphragm I6, 'I'he diaphragm'controls van obturator such as an inverted valve I1 and it is controlled, on the one hand, by the pressure-of the fuel discharged by the pump and, on the other hand, by the action of an opposing spring I8. By this arrangement, well known in itself.

-there may b'e obtained a regulation of the pressure of the fluid discharged` by the pump 9.

The pressure of the fluid discharged by the expansion device I6 is a function of the tension of the spring I8. 'I'his tension is adjustable by -a remote control I5 actuated in any suitable manner whereby the said pressure may be adjusted at every instant to the' momentary work-V ing conditions, such as the quantity of mixture admitted inpthe engine, the temperaturaM-the pressure or the density of the atmospheric air, in such a way as thereby to correct the richness of the mixture furnished to the engine as a function of the said conditions.

For the example according to Fig. 2, the fuel is fed in conduit 5 by means Vof va volumetric or rotary pump 91, driven by the motor, its speed beingat every instant proportional to that of the motor. Pump 31' discharges thus a'volume of fuel practically constant and at a pressure -which is a determined function of the speed of the pump and, consequently, of that of the engine.

Fuel is delivered to pump91by a tank 2l and a. feed conduit 2|. Discharge conduit 5 of said pump is connected to said feed conduit 2| or said tank 20 by means of at least one calibrated orice 22 and at least one return-conduit 23.

'Ihe section of one calibrated orifice is modifled by a needle 24 or equivalent actuated manually or automatically, such as described above, to correct the discharge pressure of the rotary pump 91, in the known manner, without 4alter-- ing the speed of rotation of said pump.

For the example according to Fig. 3, a similar arrangement is used but instead of the volumetric or rotary pump 91, a centrifugal pump 9 is driven by the engine, the discharge pressure of said pump 92 being4 likewise a function of the speed of said engine. In this alternative, a return-conduit 23 with its needle 24 or the like is equally provided to correct the discharge pressure of the pump 92 according to the actual working conditions.

What I claim is:

1. A fioatless carbureting system for an internal combustion engine, which comprises a suction pipe communicating with said engine, a throttling member in said suction pipe, a chamber, several passages of small area distributed over the whole of the surface of the wall of said chamber, a conduit enveloping the walls of said chamber and communicating with said suction pipe, a large air inlet passage opening in said chamber, means for feeding fuel into said chamber, means for controlling the feed of fuel into said chamber, and means for connecting said throttling member and said fuel controlling means. Y-

2. A fioatless carbureting system for an internal combustion engine, whichcomprises a suction pipe communicating with said engine, a throttling member in said suction pipe, a spherical chamber, several small passages distributed over the whole ofthe surface of the wall of said chamber, a conduit enveloping the walls of said chamber and communicating with said suction pipe, a large air inlet passage opening in said chamber, means for feeding fuel in said chamber, means for controlling the feed of fuel into said chamber, and means for connecting said throttling member and said fuel controlling means.

3. A floatless carbureting system for an internal combustion engine, which comprises a suction pipe communicating with said engine, a throttle member in said suction pipe, a chamber, 'means for connecting said chamber tosaid suction pipe, a large air inlet passage abutting in said4 chamber, a pump for .feeding fuel in a conduit opening in the central part of said chamber in an opposite direction to the entrance of air by means of said large passage, means vfory controlling vthe feed of fuelinto said chamber, and means for connecting said throttling member and said fuel controlling means.

4. A floatless carbureting system for an internal combustion engine, which comprises a suction pipe communicating with said engine, a throttling member in said suction pipe. a chamber, means for connecting said chamber to said suction pipe, a large air inlet passage abutting in said'chamber, a pump for feeding fuel in a conduit opening in the central part of said chamber and in an opposite and offset direction to'.the entrance of air by means of'said large passage, means for controlling the feed of fuel into said chamber, andmeans for connecting said throttling inember and said fuel controlling means.

tion pipe communicating with said engine, a`

throt'tiing member in said suction pipe, a chamber, means having a small effective' area for connecting said chamber to said suction pipe, air inlet )means having a large effective area and opening in said chamber, whereby the pressure in said chamber is substantially independent of variations in the suction in said suction pipe, a pump for feeding fuel into said chamber opening thereinto at a point of substantially maximum cross section, means for controlling the feed of fuel into said chamber, and means operatively connecting said throttling member and said fuel controlling-means for simultaneous movement.

6. A oatless carbureting system for an invternal combustion engine, which comprises a suction pipe communicating with said engine, a

throttling member in said suction pipe, a chamber, means having a small effective area for connecting said chamber to said suction pipe, air inlet means having across section less thanthat of said chamber but greater than that of said connecting means andopening in said chamber, whereby the pressure in said chamber is substantially independent of variations in the suction in said suction pipe, a pump for feeding fuel into said chamber opening thereinto, means for controlling the feed of fuel into said chamber, and

means operatively connecting said throttling member and said fuel controlling means for ,simultaneous movement.

7. Ina device as claimed in claim 5, a conduit connecting said pump to said chamber, means in said conduit for controlling the feed of fuel into V said chamber and controllable means for varying the ow of fuel through said conduit, said Vcontrollable means being adapted to occupy a plurality of positions in which it permits different amounts of fuel to lowthrough the conduit, and being operable at varying pump pressures, soA as to correct the discharge pressure .of said pump and thereby the strength of the fuel-air mixture fed into said suction pipe.

8. In a device as claimed in claim 5, a conduit connecting said pump to said chamber, means in said'conduit for controlling the feed of fuel into said chamber and controllable means for varying the flow of fuel through said conduit, said controllable means being adaptedto occupy a plurality of positions in which it permits different amounts of fuel to flow through the conduit, and being operable at varying pump pressures, so as to correct the discharge pressure of said pump and ,thereby the strength of the fuel-air mixture fed into said suction pipe, said controllable means being independent of the quantity of air admitted into the said carbureting system.

, MARCEL MENNESSON.

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