US2857898A - Fuel distribution systems - Google Patents

Description

Oct. 28, 1958 G. COHN FUEL DISTRIBUTION SYSTEMS FiledJuly 25. 1955 2 Sheets-Sheet 1 0 l "'K H INVENTOR. 650265 (Jo/41v 1 ATTORNEY s w 8 m o 4 4 n H 1 Ti Hm v. I! A I. M I man |l I. i L h m a H- A M UM. m 4 I 4 2 M Oct. 28, 1958 G. COHN I FUEL DISTRIBUTION SYSTEMS.

2 Sheets-Sheet 2 Filed July 25. 1955 III!! .N y 2 H WM United States Patent Ofiice 2,857,898 Patented Oct. 28, 1958 FUEL DISTRIBUTION SYSTEMS George Cohn, New York, N. Y.

Application July 25, 1955, Serial No. 524,117

11 Claims. (Cl. 123-122) it is not uncommon for unatomized fuel droplets to be passed into the combustion chambers. Such unatomized liquid fuel adversely affects engine efficiency, causes dilution of the crank case oil, thereby reducing the lubric properties of the oil and increasing friction and carbon build up, and brings about a marked decrease in thermal and mechanical efficiency.

Broadly, it is an object of the present invention to provide an improved carburetor and manifold system for internal combustion engines obviating one or more of the aforesaid difficulties. Specifically it is within the contemplation of the present invention to bring about more effective atomizing of the liquid fuel prior to delivery to the combustion chambers of the engine cylinders. To advantage smoother, more powerful and more economical engine operation results from the thorough atomizing of the liquid-fuel mixture.

In accordance with an illustrative embodiment demonstrating features of the present invention, there is provided an internal combustion engine including a carburetor having an upstanding duct along which an air-fuel mixture flows; a manifold including a main body formed with outlet ports adapted to be connected to the engine cylinders, a first inlet passage in alignment with the upstanding duct and connecting the duct to the main body of the manifold, and at least one additional inlet passage extending at an angle to the first inlet passage and connecting the duct to the main body; an unheated and non-restrictive fuel diffusing unit in the upstanding duct of the carburetor for at least partially vaporizing the mixture; and a heated and restrictive fuel diffusing unit along the first inlet passage for vaporizing further portions of the mixture after passage through the non-restrictive diffusing unit.

The arrangement is such that the main or upstanding duct of the carburetor and the aligned inlet passage of the manifold provide a continuous flow path for the heavier or unvaporized fuel particles or droplets, while the additional inlet passages of the manifold provide a non-restricted fiow path, in a changed direction, from the continuous flow path which receives the lighter and vaporized particles leaving the unheated and non-restricted fuel diffusing unit. The cumulative effect of the non-restrictive and restrictive diffusing units is such as to attain a more thorough vaporization of the liquid fuel. By the described structure, which is subject to the latitude of variation, it is possible to separate the smaller, light weight and well diffused fuel particles from the larger, heavier weight and undiffused particles, selectively treat the larger particles, and recombine the vaporized fuel mixture before delivery to the respective combustion chambers.

Numerous advantages are realized by employing fuel distribution systems in accordance with the present invention. Among these advantages are provision of a cleaner burning mixture, the elimination of sticky engine valves, material reduction in carbon. formation, more complete utilization of the fuel resulting in operating economy, smoother more powerful operation on thinner or leaner mixtures, smoother idling action, increased engine torque (especially at low speeds), less tendency for premature detonation, the capacity to increase the compression ratio of some engines, a cooler mixture before combustion; and reduction in thinning of oil.

The above brief description, as well as further objects, features, advantages and numerous modifications of the invention will be best appreciated by reference to the following detailed description of several illustrative forms of the invention, when taken in conjunction with the accompanying drawings, wherein:

Fig. 1 is an elevational view of an improved fuel distribution system for an internal combustion engine embodying features of the present invention;

Fig. 2 is an enlarged sectional view taken substantially along the line 2-2 of Fig. l and looking in. the direction of the arrows;

Fig. 3 is a sectional view taken substantially along the line 33 of Fig. 2 and showing the leading face of the Venturi plate of one of the fuel diffusing units;

Fig. 4 is a sectional view taken substantially along the line 4-4 of Fig. 2 and looking in the direction of the arrows;

Fig. 5 is a detailed fragmentary section showing the details of the diffusing unit incorporated in the manifold;

Fig. 6 is a perspective view, with parts in section of a modified Venturi plate suitable for use in the illustrative forms of the present invention;

Fig. 7 is a sectional view of a further modified Venturi plate suitable for use in the illustrative forms of the present invention;

Fig. 8 is a sectional view of a still further modified form of a Venturi plate suitable for use in the illustrative forms of the present invention; and, v

Fig. 9 is a sectional view of a still further modified Venturi plate suitable for use in the several embodiments of the present invention.

Referring now specifically to the drawings there is shown in Fig. 1 the general arrangement of an illustrative fuel distribution system for an internal combustion engine demonstrating the principles of the present invention. Specifically, the illustrative arrangement includes a conventional carburetor, generally designated by the reference numeral 10 having a main vertically extending fuel and air charging duct 12 terminating at its lower end in a flange 14. Air is introduced into the duct or passage 12 from an appropriate filtered source (not shown) along the vertical flow path of the duct 12, while the fuel is introduced into the duct 12 from a laterally-communicating float chamber 16 via a fuel. jet 18. Intermediate the float chamber 16 and the flange 14 there is provided a butterfly valve 20 which serves to selectively constrict the duct or passageway 12 in accordance with the principles which are well understood. The described carburetor 10 is conventional and is subject to a latitude of change in construction and detail.

Spaced below the carburetor 10 is a manifold, generally designated by the reference numeral 22, and illustrated as of a construction suitable for a six cylinder engine. The manifold 22 includes a main body 24 having three ports 26, 23, and 30 each adapted to be con- 3. nected to the combustion chambers of a pair of engine cylinders. A first inlet passage or duct 32 is provided in alignment with the upstanding duct 12 and communicates with the main body 24 adjacent the port 28. Additional tubular ducts or passage-forming members 34, 36 are arranged to provide inlet extending between the first or main inlet passage 32 and the main body 24 of the manifold 22. Specifically, the passage 34 has its entry end 34a arranged at substantially right angles to the vertical flow path defined by the main passage 32 and has its exit end 34b contiguous to the port 26; the passage 36 has its entry end 36a arranged at substantially right angles to the main duct 32 and has its exit end 36b contiguous to the port 30.

Interposed between the carburetor and the manifold 22 is an unheated non-restrictive fuel diffusing unit (Fig. 2), generally designated by the reference numeral 40. This unit is illustrated as a separate device for attachment between the flange 14 of the carburetor 10 and the flange 38 of the manifold 22 and includes a bipartite housing 42 having housing parts 44, 46. The upper housing part 44 terminates in a flange 48 substantially coextensive with the flange 14 and is connected thereto by several bolts 43. Similarly the lower housing section 46 includes a flange 50 connected by bolts 45 to the flange 38. As is well understood appropriate gaskets may be interposed between the respective abutting flanges to provide fluid and air-tight connections. The housing parts 44, 46 are assembled with a multiple Venturi plate 52 which is arranged within the housing 42 symmetrically of its mid plane. The Venturi plate 52 is surrounded by an annular flange 53 interposed between the flanges 54, 56 of the housing parts and connected there between by the bolts 58. The Venturi plate 52 occupies 'a medial position in the interior of the housing 42 and includes a number of Venturi passages 60 which have constrictions 60a lying substantially in a common plane. As seen in Fig. 3 and 4 the Venturi passages 60 are in a honeycomb pattern and include tapered upper and lower passage parts 60b, 600 leading respectively into the upper and lower faces 52a, 52b, of the plate 52. The upper tapered parts 60b are bevelled and rounded such that the opening of the Venturi passages into the upper face 52a of the plate 52 represents a minimum of plate surface to the flow of the liquid-fuel mixture from the carburetor 10 toward the manifold 22 and causes the least restriction to such flow. It is preferable to form the Venturi passages or orifices as close together as possible, as in the illustrated honeycomb pattern, which further contributes to presenting a minimum surface to impede the oncoming gaseous mixture which is to be delivered to the combustion chambers. This non-restrictive unheated type of Venturi unit produces a strong vaporizing action and at the same time somewhat cools and refrigerates the gaseous mixture. The action of the Venturi passages, which alternately accelerates and decelerates the fuel and air mixture is effective to at least partially break the fuel into smaller lightweight particles.

The housing parts 44, 46 are constructed to provide equalizing chambers 62, 64 above and below the Venturi plate 52 which communicate respectively with the duct 12 of the carburetor 10 and the main duct 32 ,of the manifold 22. It should be appreciated that the fuel diffusing unit or unheated multiple Venturi 40 is subject to a latitude of variation in construction and that other arrangements will be equally suitable to vaporize a major portion of the gaseous mixture without constricting or lessening the volume of flow. For example, although the unit40 has been illustrated as being separate from the carburetor 10 and the manifold 22, it should be apparent that the unit may be built as part of the carburetor 10 or as part of the main intake passage of the manifold 22.

Arranged in the main duct or passage 32 of the manifold 22 below the entry ends of the angularly extending ducts or passages 34, 36 is a further fuel-diflfusing unit Ill 66 shown in detail in Fig. 5. The further unit 66 is a heated multiple Venturi of the restrictive type surrounded by a heating chamber or compartment 68. The arrangement of fuel dilfusing or Venturi units 40, 66 is such that the entire fuel mixture is subject to the action of a first diffusing unit 40 and the undifiused portions or particles of the mixture are subjected to further diffusing action in the second diffusing unit 66. As is well understood, the suction created by the engine during the intake stroke is effective to draw a vacuum within the respective passages or ducts 32, 34, 36 of the manifold 22. As the air fuel mixture passes through the unit 40 along the gravity flow path and under the action of the vacuum, a portion of the mixture will be thoroughly vaporized and somewhat cooled. When the mixture reaches the junction 70, the mixture is presented with a restricted flow path provided by the duct 32 which is a substantial continuation of its normal flow path, and angularly extending non-restricted flow paths provided by the ducts 34, 36. In that the flow path 32 is constricted by the presence of the fuel diffusing unit 66 there is an automatic selection or sorting action. The lighter weight and well diffused particles take the paths of least resistance, namely along the ducts or passages 34, 36, while the heavier and undiffused particles tend to follow the vertical or gravity flow path and thus are subjected to the further diffusing action. A cooler mixture is ultimately provided in that the well diffused particles are not heated in unit 66. The diffusing units and the illustrated manifold arrangement serve temporarily to separate the smaller and larger particles of the fuel mixture; the unit 66 further acts on the larger particles effecting a more thorough diffusing action, and the manifold arrangement serves to recombine the mixture which consists essentially of the singly diffused and somewhat refrigerated flow from ducts 34, 36. Heat for the Venturi unit 66 may be provided directly from the manifold in those engines employing a heated manifold; or in the alternative, separate provision may be made for heating of the unit 66. The described manifold and diffusing arrangement allows the lighter well vaporized particles to flow through" the passages 34, 36 and selects the heavier unvaporize'd particles to be subject to the effect of the heated multiple Venturi unit 66, the latter being conveniently built direct ly into the manifold. The engine suction draws the heavier particles through the heated unit and eventually these particles are mixed with the cooler and previously diffused particles and serves to keep these particles-hi1 suspension until the mixture is eventually consumed iii the combustion chambers. The combination of the Venturi units 40, 66 is exceptionally useful in that the gases passing through the carburetor 10 and through the first unit 40 are subjected to a rather strong vaporizing action. This causes a drop in temperature in the gases, which counteracts overheating in the manifold. In turn the manifold is designed such that the heated unit 66 is directly in line with the unheated unit 40 while the passages 34, 36 present a sharp bend or change in direction to the fuel particles. The sharp turns or bends, which are preferably right angle bends relative to the vertical flow path, allow the lighter well vaporized particles to pass through without cumulative action while the heavier unvaporized particles are drawn through the heated multiple Venturi unit 66. Thereupon the gases are mixed to form a dense well suspended mixture which gives smooth idling, greater torque and improved economy. Further as the fuel mixture burns with less tendency to detonate, the compression ratio of the engine may be raised, thus making a more eflicient enginein that more power is extracted per unit of fuel consumed.

One or both of the Venturi units 40, 66 are subject: to a latitude of variation in structure, with the limitation that the unit 40 be of the non-restricted and unheated type and the unit 66 must be of the restricted and heated type. For example the Venturi plates may take any of the forms illustrated in Figs. 6 to 9 inclusive.

In Fig. 6 there is illustrated a Venturi plate 80 which includes a plurality of rings 82 of progressively larger diameter mounted within an outer annular frame or flange 84 and supported by spacer rods or ribs 86. The section of the respective rings is selected to accelerate fluid flow in attaining the desired Venturi action.

In Fig. 7 there is shown in cross section a further Venturi plate 96 which is formed with oppositely convexed upper and lower faces 92, 94 to provide a variation in the length of the Venturi passages 96. Specifically, the passages 96 become shorter at locations spaced progress ively outwardly from the center of the Venturi plate 90. By employing the curved surfaced Venturi plate it is possible to vary the flow of the gaseous mixture in accordance with design considerations.

In Fig. 3 there is illustrated a further form of Venturi plate 160 in which the upper and lower faces are concavely curved, as indicated by the numerals 102, 104, to obtain substantially the opposite flow distribution or characteristic from the form illustrated in Fig. 7.

In Fig. 9, there is shown a still further Venturi plate 110 of stepped construction in which successive Venturi passages are arranged in circles concentric of the central passage 112. For each ring of Venturi openings, the plate is stepped down, for example as illustrated by the reference numeral 114.

From the foregoing detailed description of the several forms of the present invention, it will be appreciated that the present multiple, Venturi fuel distribution systems may be designed for use with any type of combustion engine. Fuel distribution systems designed in accordance with the outlined principles assure better engine operation, more perfect utilization of the fuel and minimize servicing problems incident to carbon formation and the like resulting from the delivery of unatomized fuel to the combustion chambers of the engine.

In the appended claims it should be expressly understood that the term unheated multiple Venturi and equivalent terminology includes Venturi units which are not directly heated; however, such units may become somewhat heated in use as a result of direct contact with other parts of the assembly which are directly heated by exhaust gases or otherwise.

Numerous modifications are intended in the foregoing disclosure and accordingly the appended claims should be construed broadly and as is consistent with the disclosure herein; in some instances some features of the invention will be used without a corresponding use of other features.

What I claim is:

1. In an internal combustion engine, a manifold including a main duct having outlet ports in communication with the engine cylinders and plural inlet passages, the arrangement of said inlet passages being such as to provide substantially equal fuel distribution to the engine cylinders, means for introducing an air-fuel mixture into said manifold including a conduit in communication with said inlet passages, said conduit and one of said inlet passages being in substantial vertical alignment to provide a gravity flow path for unvaporized fuel particles, fuel diffusing means in said conduit for diffusing said air-fuel mixture, and further fuel diffusing means in said one inlet passage.

2. In an internal combustion engine including a fuel and air charging duct for delivering an air-fuel mixture and a manifold communicating with said duct and having plural passages adapted to be connected to the cylinders of said engine, one of said passages being in substantial alignment with said duct, an unheated multiple Venturi in said duct for at least partially vaporizing the airfuel mixture, and a heated multiple Venturi in said one passage for vaporizing heavier particles of said mixture,

3. In an internal combustion engine, a carburetor including an upstanding duct along which an airfuel mixture flows, a manifold having a main body formed with outlet ports adapted to be connected to the engine cylinders, a first inlet passage in alignment with said upstanding duct and connecting said duct to said main body, at least one additional inlet passage extending at an angle to said first inlet passage and connecting said duct to said main body, an unheated and non-restrictive fuel diffusing unit in said upstanding duct for at least partially vaporizing said mixture, and a heated and restrictive fuel diffusing unit in said inlet paassage for vaporizing portions of said mixture whch remain unvaporized after passage through said non-restrictive diffusing unit.

4. In an internal combustion engine, a manifold including a main duct having outlet ports in communication with the engine cylinders and plural inlet passages, the arrangement of said inlet passages being such as to provide substantially equal fuel distribution to the engine cylinders, means for introducing an air-fuel mixture into said manifold including a conduit in communication with said inlet passages, said conduit and one of said inlet passages beng in substantial vertical alignment to provide a gravity flow path for unvaporized fuel particles, fuel diffusing means in said conduit for diffusing said air-fuel mixture,'

equalizing chambers of substantially equal area at opposite sides of said fuel diffusing means, and further fuel diffusing means in said one inlet passage.

5. In an internal combustion engine, a manifold including a main duct having outlet ports in communication with the engine cylinders and plural inlet passages, the arrangement of said inlet passages being such as to provide substantially equal fuel distribution to the engine cylinders, means for introducing an air-fuel mixture into said manifold including a conduit in communication with said inlet passages, said conduit and one of said inlet passages being in substantial vertical alignment to provide a gravity flow path for unvaporized fuel particles, non-restrictive fuel diffusing means in said conduit for diffusing said air-fuel mixture, and restrictive fuel diffusing means in said one inlet passage, said non-restrictive fuel diffusing means including a plate extending across said conduit and having plural Venturi openings, the leading face of said plate being constructed to present minimum restriction to the oncoming air-fuel mixture.

6. In an internal combustion engine, a carburetor including an upstanding duct along which an air-fuel mixture flows, a manifold having a main body formed with outlet ports adapted to be connected to the engine cylinders, a first inlet passage in alignment with said upstanding duct and connecting said duct to said main body, at least a pair of additional inlet passages extending substantially at right angles to said first inlet passage and connecting said duct to said main body, an unheated non-restrictive fuel diffusing unit in said upstanding duct for at least partially vaporizing said mixture, and a heated restrictive fuel diffusing unit in said first inlet passage for further vaporizing portions of said mixture after passage through said non-restrictive diffusing unit.

7. For use in an internal combustion engine including a fuel and air charging duct for delivering an air-fuel mixture and a manifold communicating with said duct and having plural passages adapted to be connected to the cylinders of said engine, one of said passages being in substantial alignment with said duct and the remaining passages extending at an angle relative to said one passage, an unheated and non-restrictive multiple Venturi in said duct for at least partially vaporizing the air-fuel mixture, and a heated restrictive multiple Venturi in said one passage, the lighter particles of said mixture flowing through said remaining passages directly to the cylinders of said engine, the heavier particles of said mixture which are not vaporized by said unheated non-restrictive multipie Venturi flowing through said heated restrictive multiple Venturi to the cylinders of saidengine.

8.'For use in an internal combustion engine including afuel and air charging duct for delivering an air-fuel mixture and a manifold communicating with said duct and having plural passages adapted to be connected to the cylinders of said engine, one of said passages being in substantial alignment with said duct and the remaining passages extending at an angle relative to said one passage, a first multiple Venturi in said duct for at least partially vaporizing the air-fuel mixture, and a second multiple Venturi in said one passage, the lighter particles of saidmixture flowing through said remaining passages directly to the cylinders of said engine, the heavier particles of said mixture which are not vaporized by said first multiple Venturi flowing through said second multiple Venturi to the cylinders of said engine.

9. In. an internal combustion engine including a fuel and aircharging duct for delivering an air-fuel mixture and a manifold communicating with said duct and having plural passages adapted to be connected to the cylinders of .said engine, one of said passages being in sub-:

stantial alignment with said duct, an unheated multiple Venturi plate in said duct for at least partially vaporiz-L ing the air-fuel mixture, a heated multiple Venturi plate in said one passage for vaporizing heavier particles of said mixture, each of said Venturi plates having bores each formed with a constriction intermediate it's ends, the lighter particles of said mixture flowing directly to the cylinders of said engine, an accelerating pump .for delivering additional air-fuel mixture, and means for feeding the output of said accelerating pump into said unheated multiple Venturi plate substantially in the plane of the constrictions of said bores. I

10. In an internal combustion engine including a fuel and air charging duct for delivering an air-fuel mixture and a manifold communicating with said duct and having plural passages adapted to be connected to the cylinders of said engine, one of said passages being in substantial alignment with said duct, a non restrictive Venturi plate in said duct for at least partially vaporizing the air-fuel mixture, a restrictive Venturi plate in said one passage for vaporizing heavier particles of said mixture, each of said Venturi plates having bores each formed with a constriction intermediate its ends, the lighter particles of said mixture flowing directly to the cylinders of said engine, an accelerating pump for delivering additional air-fuel mixture and means for feeding the output of said accelerating pump into said non-restrictive multiple Venturi plate substantially in the plane of the constrictions of said bores.

11. In a fuel distribution system, a main duct having outlet ports in communication with engine cylinders and plural inlet passages, means for introducing an air-fuel mixture into said main duct including a conduit in communication with said inlet passages, said conduit and one of said inlet passages being in substantial alignment to provide a flow path for unvaporized fuel particles, fuel diffusing means in said conduit for difiusing said air-fuel mixture, and further fuel diffusing means in said one inlet passage.

References Cited in the file of this patent UNITED STATES PATENTS 1,973,889 Timian Sept. 18, 1934 2,400,035 Weber May 7, 1946

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