US2062496A - Carburetor - Google Patents

Description

O. BRKEL A CARBURETQR Dec; l, 1936.

Filed Deo. 21, 1934 lPatented Dec. 1, 1936 UNITED STATES PATENT OFFICE CARBURETOR Otto Brkel, Hamburg, Germany Application December 21, 1934, Serial No. 758,690

` In Germany December 22, i933 1o claims.

show the drawbacks, that the nozzles are easily Y clogged up by impurities and that the fuel in the float chamber frequently is ignited, whereby vast damages may be caused. The so-called surface carburetors and filter carburetors are also frequently used. At these carburetors the fuel is' supplied through capillary bodies consisting of wicks or otherbodie's of wadding or similar substances inv which the fuel is atomized, so that it enters the suction chamber of the engine in the form of spray or vapor.

The carburetors are usually controlled by throttling the passage through which the gas current flows and for this purpose a throttle flap or a similar device is provided. It has also been proposed in addition to this controlto arrange a special fuel valve for thecontrol of -the fuelsupply.

The present invention is based on a surface carburetor which is equipped with a holder having a seat for a compressible capillary body by means of which the fuel is nely distributed and is vaporized so that itk enters the air-gas conduit in the form of vapor. This seat, which through a plurality of channels or ducts communicates with the airga sconduit, is in accordance with the present invention so arranged, that 'it canleasily be set for normal load and by regulation can be 'adjusted afterA the varying loads without dinic ulties. The seatv is further so shaped, that it contacts-with a relatively large part of the surface of the capillary body. The individual' parts` of the carburetor are hereby so formed and ar- 40 are thoroughly mixed.

It is already known to equip iloatless carburetors for internal combustion motors with acapillary body holder adapted to receivea capillary 45 body through which the fuel enters the holder, and it also known in such carburetors to control the admission of air by means of a springcontrolled piston valve which cooperateswith a conical valve needle projecting into the bore. of the capillary body holder. At the hitherto knownH carburetors of this kind, however, the fuel does not pass uniformly through the capillarybody and on account of the unsuitable construction of the devices which control the supply of air it is 55- at `varying loadsnot possible to maintain the ranged, that the fuel vapors and the drawn-in air proper ratio between the amount of air supplied. to the mixing chamber and the amount of gasified fuel introduced into the same.

It is the main object of. the invention to eliminate the above named drawback and to provide `a carburetor in which the fuel is uniformly spread through thecapillary body and a fuel-air- 'mixture of correct composition is always obtained.

A constructional form of the invention is shown schematically byway of example in the accompanying drawing.

Fig, 1 is a vertical sectional view showing a carburetor the throttle device of which consists of a piston Valve.

Fig. 2 is a partial sectional view taken on a plane perpendicular to that of Fig. 1.

The carburetor shown in Fig. his supplied with fuel through a tube 2 which is controlled' by .an electromagnetic valve (not shown). This valve may be arranged as a separate device or may be combined with the carburetor to a single. unit. The lower fuel chamber I of the carburetor contains a capillary body 5,'whjch for instance may consist of rings of felt,y wadding, or-A the like; ,This capillary body may be more .or less compressed by means of a nut 6 whereby the normal adjustment may be' altered. It will be evident to persons skilled in the art, that the amount of vaporizedfuel admitted to the carburetor may be reduced by compressing the capillary body and augmented by loosening the nut. 6.

As 'shown in Figs. 1 and 2 the capillary body 5 is-pressed against aseat. formed by a holder 23 which is insertedA into the body of the carburetor.v rlhis holder is formed with an annular groove 23' for the reception of the capillary body Sand 4with a central downwardly projecting conical part 23" the lower end of which is cylindrical and is threaded to receive, the nut 6.

.The capillary body holder is formed with channels 8 of conical cross-section which connect the capillary. body with a; main channel 8,- whichj widens toward the side on which the capillary body islocated.` The channels 8' are distributed in a suitable manner in the body of theholder and lsome of them merge-into the annular groove 23' whereas others merge into the surface of the conicalprojection 23". Thioughthisarrangement the capillarybody is facing a'. very large suction surface. This surface is still Amore enlarged b y an insert 1, which is located between the capillary body 5 and the holderv 23 and which preferably consists o f a'wire gauze sieve. This .sieve will alsopreventparticles of the capillary body from being drawn into the -channels`8 (Fig. 1). The air drawn in has therefore its.

highest velocity-at the fuel inlet opening. At

this opening a calibrated steel matrix 3 is pressed into the rib 4 and within this matrix the conical valve needle 9 4is moving which is adjustably connected with the lifting cylinder or pistonvalve I serving as a throttling member by means of a common double cross-piece I3.

At the constructional form of the invention shown in Figs. 1 and 2 the throttle member I0 slides in a cylindrical part 29 of the carburetor. At the lower end of the member I0, inthe direction of the gas flow, a groove 25 is formed which during the downward stroke is entered by the rib 4 of the holder 23. For the purpose ofincreasing the nozzle effect this groove is like the said rib formed with inclined faces intermediate itsvertical and horizontal faces. The inclined faces on both sides of the lower part of the throttle device serve the same purpose.

The lifting cylinder or piston valve II) serving as athrottle device possesses a hollow piston rod Ill' (Fig. l) which is adjustably arranged in the common double cross-piece I8 and which for the light running may be raised or lowered by means of the nut II. The fuel valve 9 is exchangeable and is fixed ina needle shank 9'f which is adjustably arranged in the double cross-piece I8 in which it can be fixed by means of a second counter nut I2'. Owing to the adjustability of the needle the nozzle for light runnin-g can be dispensed with, since the amount of fuel needed for light 'running can be closed by` means .of the needle.

According as. the motor is regulated the throt- K tle device I0 will be brought more or less near to the rib 4 whereby the air inlet is correspondingly throttled. For further regulation of the air` rangement the outlet opening for the fuel will.

always lie at the narrowestpoint of the total suction path and as near as possible to the centre of the air current, so that the fuel vapor and the air are thoroughly mixed. In contrast to the known carburetors the slide plates I3 cause a sudden narrowing of the suction channel just at the fuel inlet opening whereby to the right and to the left strong eddies are created, so that the fuel and the air are thoroughly mixed.

The throttle device is reciprocated by means of a lever system consisting of two segmental bodies I5 and two links I6. The bodies I5 are pivoted at I1, and are by means of links 21 connected to the accelerator of the motor. The distance of the points ,I1 from th`e centre of the bodies I5 varies in accordance with the desired length of the stroke. When the said segmental bodies are actuated the movements of the same are by means of the links I6 transmitted to` the double cross-piece I8 to which the piston rod and thev needle shank are adjustably connected in such each other. .The effect of this arrangement is that with the throttle device in closing position, i. e. when the suction force acting upon the throttle device has its highest value, the leverage has its lowest value which increaseswhen the throttle device is lifted. The leverage of the mechanism from the beginning to thel end of the movement` of the accelerator can for instance be varied from 1:0 to 1:1.

At the place in which the air suction channel is closed by the throttle device'the cross-sectional area of the channel has in the carburetor shown in the drawing the form of a rectangle which on both sides merges into areas of circular contours. Therectangular cross-section is of great importance for this carburetor, because during the upward stroke of the device In the amqunt of air flowing in will increase proportionallywith the stroke. The needle 9 is rigidly connected to the throttle device and Imay therefore be gof exact conical shape.V If the cross-sectional area of the suction channel at this place were of curved shape the needle would have to be of arcuate shape in certain places and it would practically be impossible to give the needle such a form by grinding. The needle 9 is exchangeably xed to the needle shaft and can be adjusted for light running by means of the nut I9.

The fuel chamber of the carburetor is closed by a removable cover 24, and the cylinder 29 is at its upper end closed by a cover 26.

'Ihe carburetor can also be adjusted by other means than those described.

The fuel output of the capillary body 5 may for instance flrstbe set in accordance with the normal load by suitable compression of the capillary body. Thereupon the throttle device I0 is so set, that the motor at light running, i. e. at substantially closed throttle device, takes up the desired number of revolutions, whereby 'the regulating screw for the needle is adjusted correspondingly.

, f After the basic adjustment the lateral slide plates I3 may be `shifted in such a manner that a most favorable fuel mixture is obtained. By a simple displacement of the plates I3 the carbu? retor may also be adjusted after the varying weather conditions and temperatures.

The novel carburetor can be used at all known internal combustion motors for the gasifying of petrols of any kind. It is particularly wellsuited for air craft motors because it will workin any inclined position and even when turned bottom up. v

I claim:-

1. In a carburetorfor internal combustionmotors, in combination,`a fuel chamber, an airfuel conduitl communicating with said fuel chamberLmeans for regulating the flow of fuel into the air-fuel conduit, other means for regulating the `flow ofthe air-fuel mixture through the said conduit, a'compressible capillary body arranged in the fuel chamber and being adapted.

to cause the fuel to enter the said air-fuel conduit as vapor, a holder for the capillary body arranged between the fuel chamber and the air-fuel conduit, communication channels between the fuel chamber and the air-fuel conduit formed in the said holder, and still other means for compressing the said capillary body.

2. In a carburetor for internal combustion motors, in combination, a fuel chamber, an yairfuel conduit communicating with said fuel chamber, means for regulating the ow of fuel into the air-fuel conduit, other, means for regulating the flow of the air-fuelmixture through the said conu duit, a compressible capillary body arranged in the fuel chamber and being adapted to cause the fuel to enter the said air-fuel conduit as vapor, a holder for the capillary body arranged between the fuel chamber and the air-fuel conduit, communication channels between the fuel chamber and the air-fuel conduit formed in the said holder, a seat for th-e capillary body formedv in the said holder, said seat being of a form so as to be able to contact with a relatively large part of the surface of the capillary body, and still other means for compressing the capillary body.

3. In a carburetor for internal combustion motors, in combination, a fuel chamber, an airfuel conduit communicating with said fuel chamber, means for regulating the-flow of fuel into the air-fuel conduit, other means for regulating the duit, communication channels between the fuel chamber and the air-fuel conduit formed in the said holder, a substantially conical projection on said holder projecting into the fuel chamber, a

seat for the capillary body in the form of an annular groove arranged at the basis of said conical projection, and still other means for compressing the annular body.

4. In a carburetor for internal combustion motors, in combination, a fuel chamber, an airfuel conduit communicating with said fuel chamber, means for regulating the ow of fuel into the air-fuel conduit, other means for regulating the ow of the air-fuel mixture through the said conduit, a compressible capillary body arranged in the fuel chamber and being adapted to cause the fuel to enter the said air-fuel conduit as'vapor, a holder for the capillary body arranged between the fuel chamber and the air-fuel conduit, a seat for the capillary body formed in thesaid holder, a. substantially conical projection on the holder projecting-into the fuel chamber, a central axial bore in the holder and the projection,rsaid central axial bore opening into the air-fuel conduit andlbeing closed at the end located in the fuel chamber, branch bores betweenthe fuel chamber and the said central axial bore formed in the said holder, said branch bores widening at the end facing the fuel chamber, and still other means for compressing'the capillary body.

5. In a carburetor for internal combustion mo.- y

tors, in combinaiton, a fuel chamber, an air-fuel conduit communicating with said fuel ,cl rmber,

means for regulating the flow of fuel into the airfuel conduit, other means for regulating the flow of the air-fuel mixture through the said conduit, a compressible capillary body arranged in the fuel chamber and being adapted to cause the fuel to enter the said air-fuel conduit as vapor, a

holder for the capillary body arranged between the fuel chamber' and the air-fuel conduit, communication channels between the fuel chamber and the air fuel conduit formed in the said holder,

body and its seat, and still further means for compressing the capillary body.

6. In a carburetor for internal combustion motors, in combination, a fuel chamber, an air-fuel conduit communicating with said fuel chamber, a

chamber, a holder for said capillary body arranged between the fuel chamber and the airfuel conduit and being adapted to `cause the fuel to enter the air-fuel conduit as vapor, a substantially conical projection on said holder projecting into the fuel chamber, a central axial bore intheI holder and the projection, said central axial bore opening into the air-fuelchannel and being closed at the end located in the fuel chamber, branch bores between the fuel chamber and the said central axial bore, a piston valve for controlling the flow through the air-fuel conduit comprising a cylinder, a lpiston and a hollow piston rod, an adjustable valve needle arranged within the hollow piston rod and being adapten to control the supply of fuel in cooperation with said central axial bore, and meansfor compressing said capillary body. i

'7. A carburetor according to claim 6, in which, for an additional control of the flow through the air-fuel conduit, plate-shaped members are slidably arranged in the cylinder and in which the piston is formed with slots adapted to receive said plate-shaped members.

8. A carburetor according to claim 6, in which the said holder is formed with a rib with bevelled ends projecting into the air-fuel conduit and lying in the length direction of the same, andin which the said valve piston is formed with a correspondingly shaped slot, adapted to cooperating with the rib in regulating the cross-sectional area of the air-fuel conduit.

9. A carburetor according to claim 6, in which of two intermediate levers are connected with two segmental double-levers, somewhat below the fulcrums of the latter, and in which said segmental double-levers by means of other levers are connected to the acceleratorl of the motor.

.10. A carburetor according to claim 6, in which independent means are provided for adjusting the position of the piston and the position of the valve needle.

- OTIO' BROKEL.

l5 compressible capillary body arranged in the fuel

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