US3715108A - Staged single venturi carburetor - Google Patents

Staged single venturi carburetor Download PDF

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Publication number
US3715108A
US3715108A US00141181A US3715108DA US3715108A US 3715108 A US3715108 A US 3715108A US 00141181 A US00141181 A US 00141181A US 3715108D A US3715108D A US 3715108DA US 3715108 A US3715108 A US 3715108A
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US
United States
Prior art keywords
passage
valve
carburetor
fuel
venturi
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00141181A
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English (en)
Inventor
R Denton
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Ford Motor Co
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Ford Motor Co
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Filing date
Publication date
Application filed by Ford Motor Co filed Critical Ford Motor Co
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Publication of US3715108A publication Critical patent/US3715108A/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M19/00—Details, component parts, or accessories of carburettors, not provided for in, or of interest apart from, the apparatus of groups F02M1/00 - F02M17/00
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M7/00—Carburettors with means for influencing, e.g. enriching or keeping constant, fuel/air ratio of charge under varying conditions
    • F02M7/12—Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves
    • F02M7/22—Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves fuel flow cross-sectional area being controlled dependent on air-throttle-valve position
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S261/00—Gas and liquid contact apparatus
    • Y10S261/56—Variable venturi

Definitions

  • a downdraft type carburetor induction Passage has a 51 Int. Cl ..F02m 9/08 valve abve which is a coaxially "wumed flow
  • Field of Search "261/50 A DIG 56 60 controlling member consisting of a fixed area venturi integrated with a movable 'venturi bypass valve
  • This invention relates, in general, to the construction of a carburetor for a motor vehicle type internal com bustion engine. More particularly, it relates to a carburetor having a low silhouette and of the dual stage type.
  • hood lines on present automobiles and the predicted yet lower hood lines require some modification in the designs of carburetors so that they can continue to be installed on top of the internal combustion engine without interference from the vehicle hood, and yet supply the air flow requirements of the engine.
  • a dual stage type carburetor generally is desirable, the first stage providing high fuel metering signals at low air flows, a second stage assuring adequate air flow volume at the higher engine per formance range.
  • the primary stage of the carburetor generally requires a fixed area venturi section with one or more concentrically mounted booster venturies to provide the desired fuel metering signals at low air flows.
  • the conventional throttle valve generally is located posterior of the venturi section.
  • the secondary stage would be mounted above the venturi section and controlled by an air valve or similar device. In order to provide the primary air flow, an additional air inlet to the venturi generally would be necessary since in most instances the air valve would remain closed below a certain flow volume.
  • FIGURE schematically illustrates a cross sectional view of a portion of a downdraft carburetor incorporating the invention.
  • the FIGURE illustrates a portion of the body of a downdraft type carburetor generally used in connection with a motor vehicle internal combustion engine.
  • the body includes a large diameter central bore 11 of essentially constant cross-sectional area, which defines a conventional induction passage 12. it is open at its upper end to air essentially at atmospheric pressure. lts lower end is adapted to be connected to the intake manifold of the engine so as to subject the passage to the varying manifold vacuum.
  • the main control of flow through passage 12 is provided by a plate type throttle valve 14 that is fixed to a shaft 16 rotatably mounted in the walls of the body 10, in a manner not shown. Throttle valve 14 is rotatable from the full line position 16 shown, essentially blocking the main flow of air and fuel through passage 12, to the essentially wide open throttle dotted line position 18.
  • a profiled sleeve member 20 Located above throttle valve 14 is a profiled sleeve member 20 supported from body 10 by a number (only one shown) of struts 21.
  • the outer peripheral surface 22 of member 20 is generated in the shape of one-half of a venturi, and is adapted to cooperate with the adjacent walls 24 of passage 12 so that together surfaces 22 and 24 form a small fixed throat area venturi section 25.
  • an air flow controlling valve member 26 Concentrically located within sleeve 20 is an air flow controlling valve member 26.
  • the latter is fixed on a shaft 27 rotatably mounted in the walls of body 10 in essentially the same manner as throttle valve shaft 16. It is offset at one end as shown so as to nest with the end of throttle valve 14 when both are in the essentially vertical dotted line positions. This offers a minimum of resistance to flow through passage 12.
  • the primary fuel in this case is adapted to be discharged through an annular slot 28 in the peripheral portion 22 of the sleeve 20, the slot being located at or adjacent the throat 29 of the venturi defined between surfaces 22 and 24.
  • the fuel discharge port 28 in this case is shown connected to a main fuel bowl 30 through a conventional main discharge metering jet 32, a main fuel bowl well 34 with an emulsifying tube 35, a connecting chamber 36, and passage 38.
  • a conventional high speed air bleed 39 is also provided.
  • Additional fuel volume for secondary stage operation is provided by a metering jet 41 controlled by a metering rod 43. The latter would be connected to valve member 26, by suitable means not shown, such that rotation of valve member 26 to increase air flow also raises metering rod 43 to increase fuel flow.
  • air valve member 26 to increase the air flow may be made by any known means. In this case, it is accomplished by a vacuum controlled servo 40.
  • the latter is mounted on the carburetor, and has a conventional shell 42 with a hollow interior. The latter is divided into an atmospheric air chamber 44 and a vacuum chamber 46 by an annular flexible diaphragm 48.
  • the diaphragm 48 is fixed to a lever 50 pivotally offset connected at 52 to valve member 26.
  • a spring 53 I normally biases the diaphragm 48,. rod 50, and valve 26 to the full line closed position. shown.
  • the servo vacuum chamber 46 is connected by a vacuum line 54 to an induction passage port 56 between member 26 and throttle valve 14.
  • the carburetor could, for example, use a conventional idle system in which fuel would be drawn from the well 30 to a discharge port below the closed position of throttle valve 14 so as to supply engine idling speed fuel when the throttle is in its closed speed position.
  • venturi As soon as throttle valve 14 is rotated counterclockwise slightly, air flow through the venturi begins, providing a high metering signal at discharge nozzle 28. This draws fuel from the main well and discharges it into the passage 12, in a known manner.
  • the fixed small area of the venturi provided by the stationary surfaces 22 and 24 provides a finite schedule of flow of fuel at these times.
  • the vacuum signal at this time at port 56 will be low, and the force of servo spring 53 is chosen such that member 20 will remain in the position shown until the throttle valve 14 has rotated counterclockwise approximately 40, for example. At this point, the vacuum level at port 56 will be high enough to actuate the servo and begin moving the air valve 26.
  • the invention provides not only a low silhouette carburetor for use with low vehicle hood lines, but also one that provides dual stages of air flow operation with high venturi fuel metering signals at low air flows and high air fiow potentials.
  • a low silhouette dual flow stage carburetor having an air/fuel induction passage open at one end to air essentially at atmospheric pressure and adapted to be connected to an engine intake manifold at its other end, a throttle valve rotatably mounted in said passage for movement between closed and wide open positions to control flow through said passage, a sleeve-like fuel and air flow control member mounted anterior of said valve and spaced from the walls of said passage, said member having an outer annular arcuate contour of a profile so as together with the walls of said passage define a fixed area venturi, a valve member concentrically mounted within the hollow interior of said member and movable between positions closing or opening the said interior of said member, a fuel nozzle opening into said passage at a point adjacent said venturi so as to be subject to the varying pressure signal therein for the flow of fuel at times therefrom into said passage, said valve member in its closed position defining an initial stage flow at low throttle valve angle positions and low air flows providing a high venturi fuel metering signal, movement of said valve member to a second
  • valve member having a recessed portion receiving an edge of said throttle valve in a nested manner upon rotation of said valve to its wide open position and rotation of said valve member to its maximum air flow position.
  • a carburetor as in claim l,'said member being coaxially mounted within said passage.
  • a low silhouette dual flow stage carburetor having an air/fuel induction passage open at one end to air essentially at atmospheric pressure and adapted to be connected to an engine intake manifold at its other end, a throttle valve rotatably mounted in said passage for movement between closed and wide open positions to control flow through said passage, a fuel and air flow control member mounted anterior of said valve and spaced from the walls of said passage, said member having an outer annular arcuate contour of a profile so as together with the walls of said passage constituting a fixed area venturi, said member also constituting an air valve movable between positions to control the flow past said member, a fuel nozzle opening into said passage at a point adjacent said venturi so as to be subject to the varying pressure signal therein for the flow of fuel at times therefrom into said passage, said air valve in a closed position defining an initial stage flow at low throttle valve angle positions and low air flows providing a high venturi fuel metering signal, movement of said valve to a second stage wide open throttle valve position providing high air fiow through said passage, and

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Control Of The Air-Fuel Ratio Of Carburetors (AREA)
US00141181A 1971-05-07 1971-05-07 Staged single venturi carburetor Expired - Lifetime US3715108A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US14118171A 1971-05-07 1971-05-07

Publications (1)

Publication Number Publication Date
US3715108A true US3715108A (en) 1973-02-06

Family

ID=22494533

Family Applications (1)

Application Number Title Priority Date Filing Date
US00141181A Expired - Lifetime US3715108A (en) 1971-05-07 1971-05-07 Staged single venturi carburetor

Country Status (4)

Country Link
US (1) US3715108A (de)
CA (1) CA957225A (de)
DE (1) DE2220108C3 (de)
GB (1) GB1373267A (de)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3802671A (en) * 1972-04-06 1974-04-09 Acf Ind Inc Means preventing the extraction of fuel from the accelerating pump
US3848858A (en) * 1973-04-27 1974-11-19 K Page Velocity-actuated fuel control valve
US3883622A (en) * 1973-02-26 1975-05-13 Stephen Woods Air valve pressure diaphragm carburetor
US4375438A (en) * 1981-03-30 1983-03-01 Mckay Randolph W Carburetor and circular discharge nozzle therefor
US4420439A (en) * 1981-02-10 1983-12-13 Bosch & Pierburg System Ohg Constant pressure carburettors
US4559185A (en) * 1984-11-27 1985-12-17 Mikuni Kogyo Kabushiki Kaisha Variable venturi type carburetor
US4673536A (en) * 1983-02-15 1987-06-16 Morris George Q Fuel admixture device

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2516949C2 (de) * 1975-04-17 1983-07-28 Société Industrielle de Brevets et d'Etudes S.I.B.E. S.A, 92200 Neuilly-sur-Seine Vergaser für Brennkraftmaschinen
DE3113943A1 (de) * 1981-04-07 1982-10-14 Bosch und Pierburg System oHG, 4040 Neuss "gleichdruckvergaser fuer brennkraftmaschinen"
DE3207596A1 (de) * 1982-03-03 1983-09-15 Audi Nsu Auto Union Ag, 7107 Neckarsulm Vorrichtung zum steuern einer brennkraftmaschine

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH30791A (de) * 1904-03-24 1905-01-31 Adolph Saurer Carburator für mit flüssigem Brennstoff zu speisende Motoren
US1212986A (en) * 1915-04-02 1917-01-16 William J P Moore Carbureter.
GB200994A (en) * 1922-06-09 1923-07-26 Zenith Carburateur Soc Du Improvements in or relating to carburettors for internal combustion engines
US3628773A (en) * 1968-10-03 1971-12-21 Gen Motors Corp Carburetor
US3680846A (en) * 1971-01-08 1972-08-01 Acf Ind Inc Staged carburetor

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3243167A (en) * 1962-06-04 1966-03-29 Bendix Corp Constant vacuum type carburetor

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH30791A (de) * 1904-03-24 1905-01-31 Adolph Saurer Carburator für mit flüssigem Brennstoff zu speisende Motoren
US1212986A (en) * 1915-04-02 1917-01-16 William J P Moore Carbureter.
GB200994A (en) * 1922-06-09 1923-07-26 Zenith Carburateur Soc Du Improvements in or relating to carburettors for internal combustion engines
US3628773A (en) * 1968-10-03 1971-12-21 Gen Motors Corp Carburetor
US3680846A (en) * 1971-01-08 1972-08-01 Acf Ind Inc Staged carburetor

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3802671A (en) * 1972-04-06 1974-04-09 Acf Ind Inc Means preventing the extraction of fuel from the accelerating pump
US3883622A (en) * 1973-02-26 1975-05-13 Stephen Woods Air valve pressure diaphragm carburetor
US3848858A (en) * 1973-04-27 1974-11-19 K Page Velocity-actuated fuel control valve
US4420439A (en) * 1981-02-10 1983-12-13 Bosch & Pierburg System Ohg Constant pressure carburettors
US4375438A (en) * 1981-03-30 1983-03-01 Mckay Randolph W Carburetor and circular discharge nozzle therefor
US4673536A (en) * 1983-02-15 1987-06-16 Morris George Q Fuel admixture device
US4559185A (en) * 1984-11-27 1985-12-17 Mikuni Kogyo Kabushiki Kaisha Variable venturi type carburetor

Also Published As

Publication number Publication date
CA957225A (en) 1974-11-05
GB1373267A (en) 1974-11-06
DE2220108B2 (de) 1981-06-04
DE2220108C3 (de) 1982-02-18
DE2220108A1 (de) 1972-11-23

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