US2104013A - Method of forming a fuel charge for internal combustion engines - Google Patents

Description

Jan. 4, 1938 A. R. BAKER METHOD OF FORMING A FUEL CHARGE FOR INKIRNAL COMBUSTION ENGINES 4 Sheets-Sheet I I Jwumtom w. a $5.2: i v w v 1 M Aw H M 7 m \m V i r r w. in W\ .m 9

Jan. 4, 1938. R BA 2,104,013

METHOD O1 FORMING A FUEL CHARGE FOR- INIEW-A L COMBUSTION ENGINES I Filed Nov. 19, 19m '4 Shgets-Sheet 2' gwumtw Art/11 1222 Ba/rer v Jan. 4, 1938. A, R, BAKER I 2,104,013

METHOD OF FORMING A FUEL CHARGE FOR INTERNAL! GQMBUST'ION ENGINES Filed Nov 19, 1951. 4 Sheets-Sheet s gwwnkw Arflm rR Balrer Jan. 4, 1938. A. R. BAKER 2,104,013

METHOD OF FORMING A FI JEL CHARGE FOR INTERNAL COMBUSTION ENGINES Filed Nov. 19, 1951 4 heets-She et 4 //0. 5 2 57 R51 I.

,I i g f '2! I I s .70 V I! I 5'. i 5? W Ii g l Patented Jan. 4, 1938 I FUNITED, STATES 2,104,013 METHOD or FORMING A FUEL CHARGE FOR INTERNAL COMBUSTION ENGINES Arthur R. Baker, Indianapolis, Ind., assignor, by 'mesne assignments; to Columbia Carburetor Company, a corporation oi.' Delaware Application November 19, i931, Serial No. 576,172

4 Claims.

This invention relates to carburetion and a general object of theinvention is to provide a new and improved method of carburetion for internal combustion engines.

Another object is to provide a method of carburetion by which 'low grade gasoline or other motor fuel may be .efliciently used.

A further object is to provide a new method of carburetion by which excessive detonation may be reduced even when using low grade fuel enabling the operator to secure the same or bette'r results with a low grade gasoline than are secured by other methods with so-called high,- test or anti-knock gasoline.

A further-object is to provide a method of carburet'ion in' which detonation may be reduced without the use of an excess of fuel.

Other objects and advantages will become ap parent as the description proceeds. I,

This application is a continuation in part of my copending application Ser. No. 457,362, filed May 29, 1930 for Carbureters. now Patent No. 1,377,117.

Referring to the accompanying drawings, which aremade a part hereof and on which similar reference characters indicate similar parts,

Figure 1 is a side elevation of the carburetor as normally mountedin operative position on an engine,

Figure 2, a view in elevation from the opposite side of that shown in Figure'l;

Figure 3, aview in elevation looking from the right, as shown in Figural,

Cal

Figure 4, a section on line 4--4 of Figure 3, looking up,- 1

Figure 5, a section on the same line looking down, as indicated by the arrows in Figure 3,-

Figure 6, a vertical section taken substan- Figure 10, a section on line Ill-i8 of Figure 6,

Figure '11,:a section'on line of Flgur'e5, and

Figure 12, a modified form of ing valve.

gasoline meter- In. the drawings numeral 20 indicates the, casing of the lower section and 2| the casing ofthe upper section 'ofthe carburetor: These are secured together by a bolt, a gasket l9 being secured between them to provide the necessary seal. The lower casing is provided with an enlarged air intake port 22, said intake port be- The fuel entering through the port 28, drops into a pan 29 and when this is filled it overflows into a well 30 in which is a float 3|, said float being pivoted at 32 by means of an arm 33, said arm resting beneath a valve 34 which controls the gasoline port. The arm 33 is sufliciently resilient to take care .of any pulsations of the engine without disturbing the valve 34. From the construction just described it should be evident that the float 3| will maintain a predetermined level of fuel in the well 30 since when the float rises, the" arm 33 pressing upwardly on the valve 34 will close the inlet port. Pan 29 has a hole .drilled through the floor at 35 through which a tube'36 extends, the lower end of the tube being well down within the fuel well to draw fuel 'from near the bottom. A shoulder 31 is positioned around the bore to prevent fuel from flowing from the pan 29 directly down through the hole 35. A tube 38 is likewise positioned within a bore 39 in the pan 29. This tube is slotted as shown at 40. While the greater portion of the slot in the tube will be normally below the level of the fuel in the well, a portion of it will be above the'level of the fuel, the function of which will be presently more fully explained. Surrounding the slotted tube is a sleeve 4| which is secured in the bore 39. This sleeve has a venturi 42 near its upperend.

Within the lower end of the sleeve is pressed a plate 43 which has walls 44 forming a cup into which the lower end of the tube 38 dips.

ports 45'. The tube 38 is secured in the upper casing'2l and connects with an air intake port 46 in the top of the casing.- The-purpose of the air will be drawn through the fuel in the cup. The air therefore is washed by the fuel and takes up a portion'ofthe more easily volatilized elements of fuel so as to provide in substance a very lean fuel air mixture of a partly carburetted air.

One purpose of having the slot in the tube The sleeve 4| is provided with a number of tube 38 is to provide an intake for air, which I bore in the nut 51 at 80. The purpose of the the rod and the tube 6|.

2 v 7 38 extend abovethe fuel level is to allow the cup to be filled by fuel prior to operation of the engine. A second object of having the slot in this position is that during low or idlingspeed there may not be sufllcient suction to draw the air through the fuel in which case it will be drawn from above the fuel through this slot 40. The casing 2! is dome-shaped and the space Ill above the fuel provides a relatively force fuel up around the tube 38 and to deposit it in the pan 29.

The tube 38 is secured in the cover 2|. This tube 36 enters through the port into a chamber forming the enlarged end of a bore 48' which extends through the casing 2|. A sleeve 49 is threaded into the bore at 59. A tube Si is also threaded at 52 into the bore and this tube is surrounded by and radially spaced from the tube 49. The tube has a restricted opening 53 at its outer end and a valve rod 54 is positioned within the tube 5| and has a valve 55 positioned adjacent the restricted opening 53. The end 56 which forms the valve is made ofsuch a size as neatly to enter the restricted opening 53 and close ofi the opening without actually engaging a valve seat. The valve rod 54 is secured to a bellows 53 which bellows in turn is secured to a nut 51 which is screw-threaded into the outer end of the bore 48. The end of the rod- 54 is likewise screw threaded at I58 to receive a screw cap 53 which cap is threaded within a screw 59 is to move the rod 54 axially to adjust the size of the opening 53 around the end 55. As shown in Figure the rod 54 is grooved axially to provide a passage for fuel between The threads 80 on the screw plug 59 must necessarily be of a differentpitch from the threads 53 on the end of the rod 54 so that when the screw 59 is turned in either direction there will be an axial movement of therod 54. For example, assume that the threads on the plug 53 are 20 pitch threads, and

the threads on the rod 54 are 40 pitch threads,

' revolution of the screw 53 would move the rod 54 axially 3/40ths of an inch. A nipple BI is posite the plug 51 and a cap or cup 62 is secured then one revolution of the screw. 53 will move the rod 54 1/40th of an inch. If, however, the threads 83 should be made right-hand threads and the threads 83 left-hand threads then. one

screw threaded into the end of the bore 43 op-v upon the end of this nipple. The cap or cup 32 will be positioned in the path ofthe exhaust manifold Ill from the'engine'so as to. heat the fuel which from the tube Bl. The heated.

mixture then passes around the outside of the tube-4| and intoa chamber 33 from which it into an, axial bore 44 from which it passes throughradial bores ii over-the edge of a cup. The fuel over-thejedge of "the cup OI mixes with. in thrdllsh the intake 2.! from-which it'passes through the...- expansion chamber lfljthrough' which it enters into the intake manifold 21 of the engine.

Extending up through the head ll! sin-round ing the axial passage 64 is an axial bore into the lower end of which is inserted a short tube 3, the lower end of which-extends down within the dished portion of the cup 66. Under certain circumstances, as at slow or idle speeds, some portion of thefuel issuing from the nozzle 53 may fall into the cup, 66 as a liquid. In case ,this happens such liquid fuel will be drawn up through and delivered into the stream of fuel being drawn into the engine. This feature smooths out to a certain extent the running of a vacuum above the liquid surrounding the tube 38. This will create a suction down through the tube 38 and draw air through this tube which air will pass partly through the slot in the tube and partly through the end of the tube up through the fuel in the well. Air laden with a small percentage, of fuel will therefore be drawn through a port H4 into the annular passage 69. This air will in turn create a suction through the restricted port 53 and draw fuel through the tube 38. As the fuel issues through the restricted nozzle 53 it will become heated by contact with and by heat radiated from the casing 62 which projects into the exhaust gases from the engine.

,In Figure 12 is shown a modified formof valve. The end llSof this valve is in the form of a disk. In some carbureters now in use the fuel is raised from the fluid level to the jet 9. distance of %th to 54th of an inch This is due to the fact that there is only a very low suction created at the end of thespray nozzle. In the earbureter forming the subject matter of this invention the liquid is raised approximately 1% inches.- This is possible because of the fact thata relativelyhigh suction is created at the spray nozzle in this carbureter.

Of course the fact that the.

fuel is raised a greater height than in other carthere is a large volume oi? air passing through the carbureter. although at a relatively low veloci'ty. The restriction between the venturi and the cup 33 increases the velocity, however, sufllciently high to create a relatively high suction through the ports II, this suction pressure being transmitted to the end of the annular passage 68 around the nozzle 53. The volume of air issuing through the axial passage 63 caused by this suc-' tion serves in turn to reduce the pressure at the -no'zzle" It to create an through the tube ll.

serving to draw the fuel from the well up through,

additional high suction This suction, of course,

the tube 33." It will be apparent thereforethat the suction created at ll plus the suction created at I3 causes a relatively. high suction to the fuel 7 which is drawn through the tubeas which of course makes it possible to elevate the fuel to a much higher level than was possible with the older carbureters' One result of the high suction at the nozzle 63 is to atomize the fuel as it issues 'from this nozzle into the hot cap 62, and to more thoroughly mix the fuel and air at this point. Shown in detail in Figure 8 is the Venturishaped throttle valve, this consists of a sleeve 16 slidably positioned within the bore II and is guided by an arm I2 which slides on the lower end of a rod 16 which depends from the cup 66. The upper end of the cup 66 is screw threaded at 16 within the passage 63. The purpose of this threaded engagement is to provide, means for adjusting the cup 66 for a purpose which will later appear. n The sleeve 16 may be provided with a packing ring 16. The upper inner end of the sleeve .16 is tapered as. shown at 16. Vertical adjustment of the sleeve I6 will control the opening between the tapered side I6 of the sleeve and the edge of the head I I2 to control theamount of fuel which maypass to the. engine. The sleeve I6 is shaped with a shoulder portion 6 which cooperates witha tapered lower side II]. of the cup 66. In

head 2 and the cup 66. When the sleeve 16' is wide open the incoming air has a more direct path through the venturi. There is now,'howdraw the fuel and air into the fuel charge.' The ever, a. larger volume of'air passing through the valve. This is deflected radially by the taper II6into the enlargement around the head to create a strong suction through the annular nozzle between the cup 66 and head H2. The cup 66 preferably will be adjusted so as topr'ovide entrance of the necessary fuel to the engine during idling speed when the throttle is normally closed.

The rod I6 may be manually rotated by means of awing nut 66, or other means clamped to it so as to adjust the cup 66 with respect to the head H2. v I

When the sleeve 16 is pushed down sufficiently far its lower end engages a disk 11 to which is attached a valve 16. The valve is normally closed by a spring 16, as shown in detail in Figure '7. The valve I6 controls passage of fuel from .the pan 26; An air port 66 is drilled through the side of the casing and connects with an annular. passage 6| around the valve.

venturi. When the throttle is open wide there-1 fore the venturi gives an increased supply of fuel with a mixture of air as just described. .The

suction past the tube 62 will create suction to arm or bracket 12 has a pair of curved portions 63 which fit in an annular groove about the venturi. The arm 12 is provided with-a screwthreaded hole 64 to receive the end of an oper- The valve 66 controls entry of fuel through a bore 66 which bore is connected to the fuel pan 26. When the piston 66 is forced down fuel is forced up through the port 61 and out through radial port II6 into the intake channel II. The

bore 64 which extends'up through the casing connects with a tube 66 which'is bent over and the lower end terminates slightly above-the bottom of the fuel in the pan 26. The purpose of the bowed end 66 is to prevent fuel from freely flowing by gravity from the pan 26 through the valve 63 into the chamber beneath the piston 66. Should the fuel be allowed to flow freely by gravity a spring-pressed ball, at 62might be necessarythe fuel would flow to the low side'of the carbu-' reter so that none would be drawn into the engine when on a steep hill; In going down hill.

the operator frequently desires to accelerate the speed of the car near the footpreparatory to climbing another hill in front. Unless there were a wall such as II6 the fuel would all fall to the front of the carbureter.

The venturi which constitutes the throttle valve is operated bymeans of a toggle arrangement shown in Figure 2. This consists of an arm 61 pivoted on a screw 66 which is secured in the side of the casing 26. The arm 61 carried a pin 66 near its upper end to form a stop member. An arm I66 is rigidly secured to the side of the arm 61 and provided with a ball, |6l at its outer end to form means for attaching a lever thereto for operating the throttle.

A link I62 is pivoted to the arm 61 at I63 and is pivoted at its other end to thepin 65. To open the throttle the lever arm I66 is moved in the duties at relatively greater. opening of the throttle.

until the throttle is moved to a fully open position. As the toggle moves further to open position it ceases to operate as a toggle and becomes a positive lever. The pin 65 is-held in an eccentrio-bearing I66 which bearing is, clamped betweenthe ends I65 of the link I62. Rotation of the bearing I66 serves to adjust the opening of the throttle for idling position.

Adjustably mounted on the side of the intake manifold 21' is a rod I66. This rodcarries on its lower end a wedge-shaped member I67 which fits between the side of the upper casing 2i and the exhaust manifold I66 of the engine. The purpose of 'thewedge' I6! is to provide means for controlling the amount of heat passing from the exhaust manifold to the body of the carbureter. A nut I66 may be provided for vertically adjusting the wedge. It should be apparent thatv when the wedge is tightly fitted between the exhaust manifold and the body of the carbureter that it provides a good heat conducting medium but when it is raised. out of contactfwith these elements there is an air space between them which serves as a 'heat insulating medium;

' Operation The operation of the carbureter is as follows:

Fuel is taken in through the line. 28 and drops into the pan 29 filling this pan-up to the top of a wall. over which the remaining, fuel then spills into the well 30'. The throttle valve '58 is depressed by means of the toggle mechanism shown in Figure 2. Upon'the suction stroke of the engine air is drawn into the engine. This creates a suction around the cup 88 which suction together with the velocity of the air streaming past the cup. creates a vacuum to draw air through the annular passage 69. The air enters this passage from the following course. First it comes'into the casing throughthe air intake port 48 and passes down through the tube 88. Some of the air passes out through the slot to and up through the fuel in the well. Another and large volume of the air passes down through and out past the end of the tube 38 and up through the fuel during which course it takes up certain portions of the volatilized fuel. This air with its charge of fuel enters through port H4 into the annular passage 69 just mentioned. The velocity of the air traveling up around the tube 88, which velocity is increased by the venturi 42, acts as a pump to raise fuel from the well and deliver it into the pan 29. The velocity of the air together with the suction as the air passes out of the tube 5| creates suction within the tube 48 around the valve stem 54 to suck fuel through this tube. The fuel and the air become heated in the cap which projects into the exhaust manifold of the engine. This is a mixture of fuel which .is too rich to fire. This mixture, however, passes down through the chamber 88 and out through the ports 88 into the cup 88 where it is sucked and aspirated into the air which is being drawn in through the tube 88.

Analysis of the fuel charge in the cap 82 reveals that there is an appreciable amount of non-condensible gas or gases present in the cap. Among these gases are carbon monoxide and hydrogen. The formationof these gases is thought to be the result of a partial distillation which takes place in a partial vacuum under the heat from the exhaust manifold. In other words there is a vacuum distillation of the hydrocarbon fuels with a mixture of oxygen. The hydrocarbon fuels are partially 'broken'down into hydrogen and a part of the carbon unites with oxygen to form carbon monoxide without, howeveigany actual combus tion' taking place.' Of course, while it is believed no combustion, properly speaking, takes place nevertheless there maybe a partial combustion. In any case there .is formed an appreciable amount of non condensible, gas in the form of hydrogen and'carbon monoxide formed in the cap 82. These gases are thoroughly dispersed through the fuel charge and are carried over into the engine and form a means for conducting the ignition flames through-the fuel chargein the engine. These gases therefore serve to ignite the remaining fuel charge through its whole body substantially at the same time. The fuil body, however, is not an explosive gasbut is a relatively slow burning fuel This results in ananti-hnockor substantially non-detonating fuel chal'fle. i v

whenever the throttle is open it is desirable to increase momentarily the charge of i'uel delivered to the engine. This is provided by means of a plunger 88 which acts as a pump to inject a small volume of fuel at each time the opening of the throttle is increased. The mechanism for doing this is shown in detail in Figure 7, and consists of the plunger 88 operated in a cylinder 9|. As the throttle is opened a bracket I20 on the arm 12, which normally supports the plunger 86 by means 'of a lug .l2l, allows the piston 86 to be. forced down by the-=spring 19. As the piston is forced down fluid is forced out through the port 81 past the check valve 88 and out through the ports H8 into the main air stream where it is sucked into the engine. When the plunger 86 is raised again fuel is drawn into the cylinder 9| again so that this cylinder is kept filled with fuel. It is desirable at relatively high speeds to increase the supply of fuel delivered to the engine. Mechanism for doing this is shown in detail in Fig. 7. When the throttle I is opened very wide the velocity of the air drawn past the cup 68 is decreased, this would tend to decrease the aspiratlng effect upon the gas and air being drawn in from the chamber 84. The lower end of the venturi Ill, however, when this venturi reaches 'a certain predetermined level, strokes the disk the port 22. Should the valve 18 be held open for any reason after the car comes to a stop it should be evident that a certain amount of fuel will leak out, only that in the pan 29, however, will leak out.

As stated in the objects of the invention one of the purposes sought to be accomplished by this carbureter is to secure the same or better results with low test gasoline or other fuels as are being secured by the so-called anti-knock or doctored fuels. This is done by delivering to the engine a fuel which is thought to have a rather dense or-fog-like supply of vapor which is not readily explosive but rather which will be burned in the engineas it becomes ignited by the gases which are explosive. This supply of dense vapor is thought to be delivered to the engine for the following reasons:

The high velocity of the air which is drawn through the passage 88 carries with it a relatively large volume of fuel drawn in through the nozzle 58. This fuel and the air are heated to a relatively high temperature 'in' the tube 82. The amount of 'fuel taken up by the air is somewhat in excess of the amount that will be readily vaporized when the whole comes in contact with the cold air drawn in through the pipe 88, i. e. when the whole supply has been reduced to a low temperature by the cold air from 88 some of the fuel will be in suspension in the air somewhat as a fog. This fuel will be drawn into the engine and will supply a slow burning fuel charge in the reached the mouth of the cannon. It will there- 76 aioaoie fore be seen that if the above theory is correct the pressure in the cylinder is maintained for a longer period during the stroke of the piston than is true with fuels which explode instantly. It 6 should be obvious furthermore that the detonation will be considerably decreased.

One, fact which assists the air which is drawn through 69 in becoming so well saturated with fuel gasoline is the fact that this air is drawn or bubbled through the fuel in the well and takes up a certain amount of the more highly volatile fuels so that the air enters the tube 52 with a certain amount of fuel which has been taken aboard" so to speak, at a relatively low temperature. This then, when heated in the tube 62, will becomemore heavily laden with fuel than would otherwise be the case, or in other words, it would require a higher temperature in the tube'62 to enable a given quantity of air to take upthe desired amount of fuel.

It should be noted from the description and from the operation just given that the fuel is aerated through all of its movements in the carbureter as well as being churned up and thus aerated in the fuel pan and well. For example in the well itis aerated by the pumping action of the air which passes out through 38 up through the fuel. Thus the fuel is most completely aerated and then into a stream which ultimately issues into the stream of fuel going into the engine. This is an important fact for it means a more perfect fuel charge entering the engine for the purpose in mind.

It will be obvious to those skilled in the art 35 that various changes may be made in mgr-device without departing from the spirit of theinvention and therefore I do not limit myself to what is shown in the drawings and described in the specification, but onlyas indicated by the appended claims.

Having thus fully described my said invention, what I claim as new and desire to secure by Letters Patent, is:

. 1. The method offorming a fuel charge for in- 45 ternal combustion engines which consists in drawing air through a body of fuel by the engine suction to saturate said air with fuel sufliciently to form a carbureted mixture which is too rich to fire, heating this mixture at the point of mix- 50 ture to a temperature above the ignition point of a normal charge of the fuel to form an appreciable amount of free hydrogen and free carbon monoxide gas and, thereafter mixing relatively cold air withthe resulting mixture whereby a 55 slow burning fuel charge is formed having a mix- ,tile charge.

ture of highiy inflammable free gas therein, substantially as set forth.

2. The method of producing a fuel charge for an internal combustion engine which consists in mixing together a relatively small quantity of partially carburetted air with a relatively large quantity of fuel to form a fuel in a mixing chamher the walls of which are maintained at a higher temperature charge which is too rich for complete combustion, simultaneously heating the same by the walls of the chamber to a temperature above the ignition point of a normal charge of the fuel to form an appreciable amount of free hydrogen and carbon monoxide gas, and reversing the flow of the fuel charge during the heating, the heavier fuel elements being projected against the sides of the mixing chamber whereby liquid fuel is vaporized and heated and the lighter vaporized fuels are mixed with incoming cold air, mixing this combination of air and fuel with a large volume of relatively cold air to form a fuel charge, the cold air functioning to condense certain portions of the fuel and keep internal combustion engines which comprises ,relatlvely large volume of cool air to form the fuel charge, the addition of the cool air serving to condense an appreciable amount of the fuel charge to effect a fog-like condition in the fuel to create thereby a relatively slow burning fuel charge, substantially as set forth.

4. The method of forming a fuel charge for internal combustion engines which comprises delivering liquid fuel and air into a mixing chamber under such velocities as will cause the heavier liquid element to separate from the lighter gaseous elements mixing together the liquid fuel and the air and heating the mixture at the point of mixture, said heating being conducted so that the liquid portions of the fuel will be heated more rapidly than the lighter portions in order to gasify I the entire mixture more quickly, adding to the mixture a large volume of cool air to form a vola- AR'I'HUR R. BAKER.

Images