US1874874A - Method and means for conditioning fuel for internal combustion engines - Google Patents

Description

Aug; 30, 1932.

R. F. BRACKE METHOD AND MEANS FOR CONDITIONING FUEL FOR INTERNAL COMBUSTION ENGINES Filed Aug. 13, 1927 'llIIIIIIIII/IIIIIIIIII/J Ilflllllf! I Illlllrlllllllllll/ liliiiilllli' j? csz frzzrerz for Patented Aug. 30, 1932 UNITED STATES PATENT OFFICE ROBERT I. BIB-ACRE, OF CHICAGO, ILLINOIS, ASSIGNOR TO CURTIS 3. CW, TRUSTEE, OF GLENCOE, ILLINOIS 'KETHOD AND MEAN S FOB CONDITIONING FUEL FOR INTERNAL COMBUSTION ENGINES Application filed August 18, 1927. Serial 1T0. 212,685.

means of the character described, in which no appreciable decrease in the weight of the fuel charge is brought about by the application of heat suflicient for complete vaporization of the fuel.

A further object is to provide a method and means in which the carburetor may be quickly warmed up for eflicient operation.

A further object is to provide apparatus for conditioning fuel for internal combus tion engines, which is simple and inexpensive in construction, but which affords most favorable operating condition of the carburetor, including economy at part throttle without the sacrifice of power at open throttle. The

use of the ordinary type of hot spot for heating the air intake to the carburetor so great 1y decreases the weight of the charge for a given volume in an effort to bring about readyvaporization of the fuel that the expansive property of the fuel admitted to the manifold is reduced and therefore power is sacrificed.

A further object of the invention is to provide a. method and means of the character described in which the degree to which the fuel may be heated is under control of the driver from a point on the instrument board of the vehicle.

Other objects and advantages will be more particularly pointed out in the following specification and claims.

The invention as illustrated in the accompanying drawing forms a part of this application, in which:

Fig. 1 is a sectional view of a carburetor and engine manifold embodying my invention.

Fig, 2 is a sectional view throu h the in strument board of the vehicle il ustrating the manual control of the heater and 'Fig. 3 is a fragmentary view, partly in section, of a modified form of the invention.

In carrying out the invention I make use of an internal combustion engine having an intake manifold 10 and an exhaust manifold 11. The carburetor A has a fuel delivery passage 12 which is connected with the intake manifold 10 of the engine.

The carburetor A has a primary induction passage 13 in the form of a Venturi tube which projects through a side wall of the induction chamber 14 of the carburetor.

Fuel is drawn to the throat 15 of the primary air passage 13 by virtue of the suction multiplying principles of the Venturi from a fuel chamber 16 which communicates through a valve 17 operated by atmospheric pressure to the fuel supply tank of the vehicle. In a carburetor of this type throughout the entire operating range of the carburetor suflicient depression is maintained in the fuel chamber 16 to lift fuel thereto from a low level supply tank, utilizing therefore, only that small proportion of the amount of air admitted to the induction chamber which flows through the primary air passage 13. The major ortion of air admitted to the chamber is a 'tted through the secondary air passage 18.

It is the passage 18 which in ordinary devices receives pre-heated air to assist in conditioning fuel for carburetion that is connected with a hot air source.

The means which I employ for conditioning the fuel unlike the present means, consists in conducting warm air from a jacket 19 disposed about the exhaust manifold 11 tothe -intake orifice of the primary induction passage 13. This is done by means of a tube 20 communicating with the intake orifice of the passage at one end and with a valve chamber 21 at its opposite end, which is also connected with the jacket 19.

, A valve 22 is disposed within the chamber 1 21 which is operated by means of an arm 23 disposed exteriorly of the chamber and connected to a rod 24, the other end of which is secured to a hand-grip 25 carried by suitable supporting means 26 on the instrument board 27 of the vehicle. Longitudinal oscillation of the hand-grip 25 will cause proportionate movement of the valve 22. l

That end of the valve chamber 21 opposite to its intake opening 28'which communicates with the jacket 19 has an opening 29 communieating with the atmosphere.

The position of the valve 22 in the chamber 21 therefore determines the amount of'warm air and air at normal temperature which is admitted to the primary air passage 13 so that the temperature of the in-flowing streammay be controlled at will by actuation of the control 25.

For-warming up the engine the valve 22 is actuated by means of the hand-grip 25 so as to assume the position .shown in full lines in Fig. 1. Thus operation ofthe engine and the heating of the manifold 11 from exhaust gases, supplies only warm air to the primary passage 13, due to the fact that openin 29 in valve chamber 21 is closed. Thus t e air stream primarily uniting with fuel admitted through the throat 15 of the primary air passage materially increases the tendency of the fuel to vaporize as it is {emitted from the primary air passage into induction chamber 14. The vaporized fuel in chamber 14 is united with air at normal temperature which is drawn into secondary air passage 18 and the mixture passes up through passage 12 into the intake manifold. The charge is properly conditioned for initial operation of the engine since the warm air first admitted to the fuel delivered into chamber 14 has caused' suflicient vaporizing of the fuel to render it in the proper condition for combustion.

This method of pre-heating only a part of the air stream, being that part which primarily is united with the fuel, does not appreciably decrease the weight of the char e so as to sacrifice power as would necessari y have to occur if all the air admitted to the carburetor was heated sufliciently to cause the fuel to readily vaporize.

After the engine has been running and the carburetor body has become heated by radiation, the valve 22 is moved by actuati'on of the hand-grip 25 upon the instrument board so as to feed some air through opening 29 at normal temperature. This reduces the temperature of the air passing through the primary' air passage'13 to compensate for the then warmer air admitted through the passa e 18.

y employing this method and apparatus for conditioning the fuel, I eliminate the necessity of using excessive chokes and the like which tend to throw raw fuel into the cylinders of the engine and cause crank case dilution as well as other numerous disad vantages.

In Fig. 3 I have shown a modification of the means for warming air admitted to valve chamber 21. In this form of the invention I project a tube diametrically through the exhaust manifold 11. connecting one end'to intake opening 28 of valve 21 and the opposite end communicates with the atmosphere at the opposite side of the manifold 11. This means for heating the air does not depend upon first warming the exhaust manifold 11 but instead receives heat directly from the passage of hot exhaust gases through the manifold even prior to the warming of the manifold.

What I claim is:

1. The combination with a carburetor having a relatively small primary air passage and a relatively large secondary air passage, means for injecting fuel to said carburetor through said primary air passage, said means admitting said fuel to the primary air passage at normal temperature, and adjustable means for admitting warm air to said primary air passage prior to the admission of fuel thereto to hasten the vaporization of fuel in-jectedtherethrough.

2. The combination with a carburetor having a relatively small primary air passage communicating with the induction chamber of the carburetor and a relatively large secondary air passage communicating with said chamber, means for injecting fuel to said primary'air passa e at a point adjacent to the induction cham 'r and at normal temperature, means for warming the air admitted through said primary air passage at a' point prior to its contact with the fuel admitted thereto, an induction chamber communicating with said secondary air passage, and means for admitting heated air and fuel into said induction chamber as a cross-current to the stream of air flowing through said induction chamber from said secondary air passage.

3. The combination with the carburetor having a primary and secondary air passage, said secondary air passage being greater in diameter than the primary air passage, means for heating air admitted to the primary air passage, means for injecting fuel at normal temperature into the warm air stream passing through said primary air passage, an induction chamber, and means for admitting air and fuel from said primary air passage into said induction chamber at an angle to the axis thereof. I

. 4. The combination with a carburetor having an induction chamber and a primary and secondary alr passage, said secondary air passage being greater'in diameter than the; primary air passage, means for heating air ada point adjacent to the delivery orifice of the primary air passage.

5. The method of conditioning fuel for internal combustion engines, which consists in admitting warmed air to the induction chamber of a carburetor at an angle to the axis thereof and in injecting fuel at normal temperature into the warm air stream at a point immediately adjacent to the induction chamber.

6. The method of conditioning fuel for internal combustion engines, which consists in supplying a relatively large quantity of air at normal temperature to the induction chamber of the carburetor at the side thereof, in admitting warmed air in relatively small quantities to said induction chamber and controlling the temperature of said warmed air and in injecting fuel at normal temperature into the Warm air stream at a point adjacent to the induction chamber.

7. The method of conditioning fuel for internal combustion engines which consists in supplying a relatively larger quantity of air at normal temperature to the induction chamber of the carburetor, in admitting warmed air to the induction chamber in relatively small quantities through a separate passage, in controlling the temperature of the warmed air to compensate for the natural rise in the temperature. of air surrounding the carburetor admitted through the secondary air passage and in injecting fuel at normal temperature into the warmed air stream at a point adjacent to the induction chamber.

8. The combination with a carburetor having a relatively small primary air passage communicating with the induction chamber of the carburetor and a relatively'large secondary air passage communicating with said chamber, means for injecting fuel to said primary air passage at a point adjacent to the induction chamber and delivering directly into the same at normal temperature and means for warming the air admitted through said primary air passage an adjustable amount and at a point prior to its contact with the fuel admitted thereto. 9. The combination with a carburetor hav ing an induction chamber, a relatively small primary air passage communicating directly with the induction chamber and a relatively large secondary air passage communicating with said chamber and for delivering atmospheric air thereto, a Vent-uri tube in the primary air passage, means for injecting fuel to said primary air passage around the throat portion of the Venturi tube at normal temperature, and means for warming the air admitted through said primary air passage at a point prior to its contact with the fuel admitted thereto, said last mentioned means including adjustable means for varying the proportions of heated air and atmospheric air admitted through said primary passage.

1( The, combination with a carburetor hav ng an induction chamber, a relatively small primary air passage communicating directly with the induction chamber and a relatively large secondary air passage communicating with said chamber and for dellvering atmospheric air thereto, a Venturi tube in the primary air passage, means for injecting fuel to said primary air passage around the throat portion of the Venturi tube at normal temperature, and means for warming the air admitted through said primary air passage at a point prior to its contact with the fuel admitted thereto, said means includmg a conduit having an inlet end for the admission of air disposed so as to heat the air by the exhaust gases of a motor and having its opposite end communicating with the Venturi tube, and a valve interposed in said conduit and having an inlet at one side communicating directly with the atmosphere and movable in an arc to close said inlet or simultaneously vary the proportion of heated air (zindt atmospheric air admitted into the con- In witness whereof, I hereunto subscribe my name this 9th day of August, 1927.

ROBERT F. BRACKE.

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