US2127386A - Carburetor - Google Patents

Description

Patented Aug. 16, 1938 UNITED STATES anim PATENT MG'QE Application July 9, 1936, Serial In Sweden July 10, 1935 14 Claims.

The present invention relates to carburetors for internal combustion engines or motors of the type in which the fuel, preferably of a high boil- V ing point is mechanically sub-divided and vapourized in a vapourizing chamber located within the exhaust pipe and thereupon mixed with air and sucked away through the fuel inlet pipe of the engine.

Such internal combustion engines as use a fuel having` a high boiling point (as kerosene) usually are started with the aid of a more volatile oil (as gasoline). In such class of bi-fuel motors two carburetors are usually provided, one for crude oil the other for petroleum.

In such carburetors it has been found that the vapourizing chamber due to poor combustion and deposits of carbon will not work satisfactorily.

In order to remove such deficiencies according to the present invention the vapourizing chamber of the kerosene carburetors is of such construction and provided with means for having it swept free of remaining fue] gases and carbon residue during its idle period when the engine is driven by gasoline.

Another object of the invention is to provide means whereby the parts of the vapourizing chamber are heated also from the inside during its idle period. p

Still another object is to use a material for the construction of the Vapourizing chamber which has a high coefficient of expansion thus enabling deposits of carbon etc. to be more easily removed.

The present invention will be clearly set forth in the following description referring to an in 35i ternal combustion motor having two carburetors of which only the kerosene carburetor is described and shown in the drawing. It will be understood, however, that the carburetor as described is given as'an example only.

In the accompanying drawing:

Fig. 1 is a sectional elevation of a carburetor constructed according to one example of carrying the invention into effect.

Fig. 2 is a partial sectional elevation of the 5 kerosene vapourizing chamber in a non-working state as it is heated by the exhaust or refuse gases when the motor is driven by gasoline fed to the gasoline carburetor.

Fig. 3 is an enlarged fragmentary View in sec- ;0. tion showing certain details of construction providing for the entrance of the exhaust gases to the vaporizing chamber when the valve is closed.

In Fig. l I is a length of tubing having flanges at both ends to provide for its securing to the iexhaust pipe of which. it is intended to form a part. Thus the hot exhaust gases will pass therethrough heating the vapourizing chamber 2 located therein. The vapourizing chamber consists of a substantially cylindrical hollow casting having at its upper end a cylindrical 5 opening 3 leading to the hollow interior or bore of the vapourizing chamber 2. Said bore preferably is of a slightly conical shape tapering upwards. The wall of the vapourizing chamber 2 at its lower edge forms a valve seat 6. Where 10 the opening 3 merges into the vapourizing chamber a groove 4 is formed into the wall of said chamber. Into said groove l three passages 5 open spaced apart at the same distance around the periphery of the only being shown in the drawing. A hollow conical valve 'l is provided for closing the aperture at the lower end of the vapourizing chamber by being pressed against the valve seat At the top of the hollow valve 'l is an annular member 20 8 which at its upper part is of a cylindrical shape whereas its lower part is conical tapering upwards. On the face of said annular member 8 are recesses or grooves 3a. and the cylindrical portion of the annular member is surrounded by 25 an annular valve 9 which is made to close against a seat on the vapourizing chamber wall as shown. The annular valve 9 when closed together with the annular groove Il forms a passage communicating through an annular slot if) with v the recesses as grooves 8a in the member 8. Above the member 8 a thin annular collar ll is provided which at its face has recesses or grooves lla corresponding in number to those of the annular member 8 but which width. A hollow stem i2 is passed through said member 8 and collar l i and threaded into the conical valve l, and the top of said stem l2 forms part of a claw-coupling and a little below this portion four guiding arms forming a cross are provided. Below said cross are four passages l 5 opening into the bore of the stem I2 or the hollow of the valve 'l so as to enable the gases to pass therethrough. From the vapourizing chamber (at the right in Fig. l) a passage I6 of a comparatively great width is provided through which the vapourizing fuel` passes to the mixing chamber Vl. In order to secure a gastight fitting between the vapourizing chamber and the mixing chamber and to locate the vapourizing chamber properly a short length of a steel tube HS has been driven into the wall of the exhaust tube l, said tube i3 having a conical portion to be fitted into the passage i6.

The conical configuration of the inner faces groove, one such passage 15 of the vapourizing chamber which are also highly polished has the effect that the cokelike residue forming on the walls by decomposition of the fuel will be easily removable. Preferably also the vapourizing chamber is made from a material having a high Coeicient of expansion which greatly augments the said effect. For this reason, however, it is impossible to have the vapourizing chamber xedly positioned within the exhaust tube. As shown on the drawing a resilient fastening means I9 is provided which tends to press the vapourizing chamber both against the conical portion of the tube I8 and against a second tube Z having at one end a ball-shaped portion and being spherical at its other end, said tube 20 having a passage 23a therein through which the fuel is introduced. Said tube allows the vapourizing chamber to move without causing leaking at the joints. At the lower end of the conical valve 1 guiding means 2I are provided. At the top a lifting stem 22 is provided connected through the claw-coupling I3 with the stem I2. On each side of the eX- haust tube I there is an opening which can be closed by a shutter and through which the vapourizing tube may easily be taken out for inspection and adjustment.

In a cut-out portion of the lifting stem 22 a lever 23 is entered which lever is xed to a shaft 2.

Referring to Fig. 1, above the mixing chamber I1 the fuel valve chamber 25 is situated. It encloses the valve stem 26 which at its lower end is conical and forms a valve or needle. Below said needle we see the nozzle 21 which has a calibred opening and a valve seat 28, which conforms with the conical valve portion of the stem 26. The bore of a nipple threaded into the valve chamber 25 communicates with the bore of the nozzle and leads the fuel thereto from a vacuum tank, a floating chamber or a regulating valve.

In the valve housing 25 an adjustable air passage 29 and also a passage 30 are provided, said passage 39 communicating with the vapourizing chamber through the pipe 29 and the passages 5. The valve stem on its periphery 26 has a groove 3l of such a shape that when the valve is open the air duct 29 communicates through said groove 3| with the passage 3U. However, when the stem 26 moves downwards, its needle coming to rest against its seat 28 a cylindrical portion of the stem 26 will close the passage 29 and shut olf the supply of air entering therethrough.

The passage I6 through the pipe I8 communicates with the pipe 32 being part of the mixing chamber I1. The pipe I1 can be shut by a throttle 33. A branch pipe of the mixing chamber I1 which opens into the air can likewise be closed by a throttle 34. Levers 38 and 39 are fastened to the throttles 33 and 34 respectively and are interconnected by a rod 40 in such a way that the gas-throttle 33 is fully opened when the gasthrottle 34 is only half-opened and remains in said position until the gas-throttle has been fully opened. This may be accomplished by providing springs (not shown) on the shaft 33a of the valve 33 and shaft 34a of valve 34 arranged respectively to retain said valve 33 in the position shown and tending to close said valve 34 so that when the rod 40 is moved downwardly, for example, the valve 33 will move together with its lever 38 and when said valve has been closed the lever 39 being much longer than lever 38 will not have moved a distance sufficient to close valve 34 which may be closed only by moving the rod 40 still further downward, the lever 38 being mounted with respect to valve 33 so that it will be free to follow this further movement of said rod 49. This control of the valves 33 and 34 forms no part of the invention however and may be accomplished by various types of control mechanisms.

In the chamber I1 in front of the pipe 32 an annular sliding member 35 that is conical in crosssection and can be moved towards and away from the end of the pipe 32 thus restricting or widening the annular space 31 between said end of the pipe 32 and the annular member 35, therewith providing a means for regulating the quantity of air admitted when the air throttle 34 is fully opened. The pipe 36 is adapted to be secured to the gas inlet pipe of the engine.

The shaft 24, the means for lifting the valve stem 26 and the shaft on which the throttle 34 is mounted all are connected to means regulating the velocity of the motor-as the gas pedal-in the usual way known in the art.

In use the vapourizer works as follows:

The engine is started on the gasoline vapourizer (not shown) in the usual way. The valve 26 and the air throttle 34 (and consequently the gas throttle 33) are shut. The movable parts of the vaporizing chamber are in the position shown in Fig. 2, viz. the valve 1 is lowered. A quantity of the hot exhaust gases now will pass through the vaporizing chamber heating it also from the inside. After the engine has been worked in this way for some minutes it is possible to change over to kerosene. When the contraption is applied to automobiles double gas-pedals may be used, one

for the gasoline vapourizer and the other for the f' kerosene vapourizer; the operator effecting the change only by moving his foot from one pedal to the other. When the pedal of the gasoline vapourizer is released the air throttle pertaining thereto is shut. As the operator presses upon the kerosene pedal the valve 1 is first lifted so that it is pressed against its seat 6 and the annular member 9 will also t its seat 4.

Then the oil regulating valve 26 and the air throttle 34 are opened in conformity with the dcpressing of the pedal, viz according to the power required. The throttle 33 is not used as a regulating means but serves only to shut off the exhaust gases from the inlet pipes of the cylinders when the engine is worked by gasoline. This is the reason for the special connection between this throttle and the air throttle 34. The throttle 33 should be opened speedily.

In the inlet pipe of gas mixture to the engine and therefore also in the vapourizing chamber there reigns a pressure below air-pressure. The fuel is sucked through the nozzle 21 and mixed with a small quantity of air entering through the passage 29, then passes through the ducts 30 and 20, is distributed and passes through each of the three separate ducts and enters the annular groove 4 from different directions and passes through the annular space I0 and the grooves Ba in the member 8 where the mixture is met at an angle of 90 by a small quantity of very hot exhaust gases entering through the grooves IIa in the member I I. Owing to the low pressure in the vapourizing chamber and the high pressure In the exhaust pipe these gases attain a very great velocity so that the fuel is brought into a state of very fine sub-division. The mixture now passes along the grooves 8a in the member 8 inside of the member 9 and is expelled from the conical portion thereof against the hot walls of the vapourizer and is wholly vapourized. Part of the exhaust gases the interior of passes through the openings I5 and the valve 'I and prevents its cooling down. The vapourized fuel passes through the duct I6 and the pipe 32 whereupon it is mixed with air entering through the throttle 3d which at` 35 passes at great velocity around the mixture of fuel vapour and transports it through the intake pipe of the engine. Thereby the fuel vapour is cooled and enters the cylinders in a fog-like state adapted for the burning.

Always when the gas pedal is relievedthus also when the car is allowed to roll along under action of its` inherent kinetic force-the fuel is shut olf through the lowering of the stem` 26 so that the valveis closed-upon its seat 2B and also the air passage 29 is shut 01T. Simultaneously throttles 33 and 34 are closed. Thereupon the valve 'l is lowered and brought into the position shown in Fig. 2. The exhaust gases now are free to sweep through the vapourizing chamber and liberate it from remaining fuel gas and residues. This is very important as otherwise the remaining fuel gas at the next opening of the throttles would enter the engine as a surplus and therefore cause insufficient burning and smoking.

When idle the engine runs on gasoline fuel provided by the idle run nozzle and the change will be automatically effected as soon as the throttles 33 and 34 are shut causing a lower pressure to arise in the inlet pipe.

The vapourizing chamber that is the object of the present invention has been described as applied to a special form of carbuetor but it is clear that it may be used for other carburetors also and I do not wish to restrict my invention to any special type of carburetors or to any form of execution.

Having thus described my invention what I claim to protect is:

l. In a bi-fuel device of the character described comprising an exhaust chamber, a vapourizing chamber for heavy fuel located in said exhaust chamber, a valve controlled opening in said vapourizing chamber for the introduction of exhaust gases thereto from the exhaust chamber, and a valve controlled outlet opening in the Vapourizing chamber for returning said exhaust gases from the latter to said exhaust chamber.

2. In a bi-fuel device of the character described comprising an exhaust chamber, a vapourizing chamber for heavy fuel located in said exhaust chamber, said vapourizing chamber having an inlet opening therein for the introduction of exhaust gases thereto and an outlet opening for returning said exhaust gases to the exhaust chamber, and valve means for controlling the passage of the exhaust gases through said openings in the vapourizing chamber.

3. In a bi-fuel device of the character described comprising an exhaust chamber, a vapourizing chamber for heavy fuel located in said exhaust chamber, said vapourizing chamber having an inlet opening therein for the introduction of exhaust gases thereto and an outlet opening for returning said exhaust gases to the exhaust chamber, and a single valve element for controlling passage of the exhaust gases through said openings in the vapourizing chamber and operable to simultaneously close the openings.

4. A device as claimed in claim 1 wherein the inner configuration of the vapourizing chamber is substantially conical.

5. A device as claimed in claim 3 wherein the external configuration of the valve element is substantially conical.

6. A device as claimed in claim 3 wherein the inner configuration of the vapourizing chamber and the externalconfguration of the Valve element are substantially conical. Y l

7. A deviceas claimed in claim l wherein the vapourizing chamber is composed of material possessing a high coefficient of expansion..

8. In a bi-fuel device of the character-described, an exhaust chamber, a vapourizing chamber in said exhaust chamber having inletl and outlet openings therein for the ingress and egress of exhaust gases, and a valve element operable to open and close said openings in saidr Vapourizing chamber, the portion of said valve element cooperable with the inlet opening; being constructed and arranged with respect thereto so that the quantity of exhaust gases entering the vapourizing chamber are controlled by the relative position of the valve with respect to the opening.

9. In a bi-fuel device of the character described, an exhaust chamber, a vapourizing chamber having inlet and outlet openings therein for the ingress and egress of exhaust gases, and a valve element operable to open and close said openings in said vapourizing chamber, the portions of said valve element cooperable with the openings to close the same being constructed and arranged with respect to each thereof so that passage through said openings is controlled by the relative position of the valve with respect thereto.

returning said exhaust gases to the exhaust chamber, valve means for controlling the passage of valve means for actuating the same.

1l. In a bi-fuel device of the character described, an exhaust chamber, a vapouiizing structed and arranged with respect to each thereof so that passage through said openings is controlled by the relative position of the Valve with respect thereto, and means operatively connected to said valve means for actuating the same.

12. In a bi-fuel device of the character described, an exhaust chamber, a vapourizing chamber for heavy fuel located in said exhaust chamber, said vapourizing chamber having an inlet opening therein for the introduction of exhaust gases thereto and an outlet opening for returning said exhaust gases to the exhaust chamber, a of the ex when said inlet opening thereto is closed by the valve element.

13. In a bi-fuel device of the character described, an exhaust chamber, a vapourizing chamber for heavy fuel located in said exhaust chamber, said vapourizin-g chamber having an inlet opening therein for the introduction of exhaust gases thereto and an outlet opening for returning said exhaust gases to the exhaust chamber, a valve element for controlling passage of the exhaust gases through said openings in the vapourizing chamber and operable to close the openings, means for feeding fuel to the vapourizing chamber through the inlet opening therein, and means forming a part of said valve element constructed and arranged to permit the passage of fuel and exhaust gases to said vapourizing chamber when said inlet opening thereto is closed by the valve element.

14. In a bi-fuel device of the character described comprising an exhaust chamber, a vapourizing chamber for heavy fuel located in said exhaust chamber, said vapourizing chamber having an inlet opening therein for the introduction of exhaust gases thereto and an outlet opening for returning said exhaust gases to the exhaust chamber, valve means having a bore extending axially therethrough operative to control the passage of the exhaust gases through said openings in the vapourizing chamber, and means forming a part of said valve means constructed and arranged so that a portion of said exhaust gases pass through the bore in the valve means.

SVEN EMANUE'Lv BENGTSON.

Images