US3704867A - Low silhouette dual flow stage carburetor - Google Patents

Low silhouette dual flow stage carburetor Download PDF

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Publication number
US3704867A
US3704867A US120954A US3704867DA US3704867A US 3704867 A US3704867 A US 3704867A US 120954 A US120954 A US 120954A US 3704867D A US3704867D A US 3704867DA US 3704867 A US3704867 A US 3704867A
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US
United States
Prior art keywords
carburetor
venturi
passage
fuel
throttle valve
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
US120954A
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English (en)
Inventor
Roy E Diehl
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ford Motor Co
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Ford Motor Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Ford Motor Co filed Critical Ford Motor Co
Application granted granted Critical
Publication of US3704867A publication Critical patent/US3704867A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • F02M19/08—Venturis
    • F02M19/081—Shape of venturis or cross-section of mixture passages being adjustable
    • 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

  • ABSTRACT A downdraft type carburetor induction passage has essentially a constant cross-sectional area with a rounded edge air inlet, the rounded edge cooperating with a rotatable member having its peripheral surface in the form of an inverted semi-venturi so as to form an inverted venturi whosearea varies as a function of the rotation of the member to provide high fuel metering signals at low air flows and high air flow potential.
  • This invention relates, in general, to the construction of a carburetor fora motor vehicle type internal combustion engine. More particularly, it relates to a c'arbu retor having a low silhouette and of the dual stage type.
  • hood lines on present automobiles and the predicted yet lower hood lines requires'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 at low air flows, a second stage assuring adequate air flow volume at the higher engine performance 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 necessarysince 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.
  • FIGURE illustrates schematically a portion 10 of the main body of a downdraft type carburetor generally used in connection with a motor vehicle internal combustion engine.
  • the main bodyli includes a largediameter central bore 11 of constant cross-sectional area that defines the conventional induction passage 12.
  • the main control of flow through the passage is providedby a 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 l8 offering a minimum of resistance to flow of fuel and air through passage 12. 2
  • a profiled annular or disc-like member 20 fixed on a shaft 22 rotatably mounted in the main body l0 in a manner similar to that of the throttle valve shaft 16.
  • the peripheral surface 24.of member 20 has a semi-torodial like profile that corresponds to one half of an inverted venturi.
  • the profiled surface 24 is adapted to cooperate with the rounded edge inlet air passage portion 26 formed on main body 10 so that together surfaces 26 and 24 form a complete inverted venturi section.
  • the fuel in this case is adapted to be discharged through an annular slot 28 in the peripheral portion of the body 10, the slot being located at or adjacent the throat 29 of the venturi defined between surfaces 24 and 26.
  • the fuel dischargeport 28 in this case is shown connected schematically to a main fuel bowl 30 through the conventional main discharge venturi 32, a main fuel bowl well 34, and a connecting chamber 38.
  • a vacuum controlled servo 40 The counterclockwise movement of profiled member 20 to increase the air flow and also vary the venturi area is accomplished by a vacuum controlled servo 40.
  • the latter is mounted on the carburetor, and has a conventionalshell 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 member 20, a spring 53 normally biases rod 50 and member 20 to the full line position shown.
  • the servo vacuum chamber 46 is'connected by a vacuum line 54 to an induction passage port 56 between the member 20 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 the throttle valve 14 so as to supply engine idling speed fuel when the throttle is in its closed speed position.
  • the increase in manifold vacuum signal acting on the servo 40 will begin to rotate the member 20 so as to progressively increase'the area of the venturi and also increase the air flow through passage 12. This action continues until the throttle valve 14 reaches the wide open throttle position 18, at which time the member 20 will have rotated to its dotted line position 58.
  • the member 20 provides a maximum area venturi at wide open throttle valve position and a maximum air flow potential by its rotation to a nearly vertical position.
  • 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 flow potentials.
  • a low silhouette dual flow stage carburetor having an air/fuel induction passage with an essentially constant area at one end, and adapted to be connected to an engine intake manifold at its other end, said inlet having a rounded inlet edge, 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 rotatably mounted anterior of said valve and spaced from the walls of said passage, said member having an arcuate contour so as together with said air inlet rounded edge define a variable area venturi varying in area as a function of the rotative movement of said control member, and 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 member being variably movable from an initial stage minimum venturi area position at low throttle valve angle positions and low air flows providing a high venturi fuel metering
  • said fuel nozzle being variably movable from an initial stage
  • a carburetor as in claim 1 said 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 member to its maximum air flow position.
  • a carburetor as in claim 1 the peripheral surface of said member having the profile of one-half of an inverted venturi.

Landscapes

  • 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)
  • Control Of Throttle Valves Provided In The Intake System Or In The Exhaust System (AREA)
US120954A 1971-03-04 1971-03-04 Low silhouette dual flow stage carburetor Expired - Lifetime US3704867A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US12095471A 1971-03-04 1971-03-04

Publications (1)

Publication Number Publication Date
US3704867A true US3704867A (en) 1972-12-05

Family

ID=22393496

Family Applications (1)

Application Number Title Priority Date Filing Date
US120954A Expired - Lifetime US3704867A (en) 1971-03-04 1971-03-04 Low silhouette dual flow stage carburetor

Country Status (5)

Country Link
US (1) US3704867A (de)
CA (1) CA950291A (de)
DE (1) DE2202616C3 (de)
FR (1) FR2127646A5 (de)
GB (1) GB1344127A (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4211196A (en) * 1977-05-12 1980-07-08 Societe Pour L'equipement De Vehicules Carburetor
US4268462A (en) * 1979-01-18 1981-05-19 Nissan Motor Company, Limited Variable venturi carburetor

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1093901A (en) * 1912-12-06 1914-04-21 Horace B Wyman Carbureter.
US1277963A (en) * 1914-10-22 1918-09-03 Ralph M Lovejoy Carbureter.
US2877003A (en) * 1955-06-22 1959-03-10 Acf Ind Inc Tangential nozzle type carburetor
US3214150A (en) * 1961-07-03 1965-10-26 Ohlsson & Rice Inc Carburetor
US3253822A (en) * 1964-03-09 1966-05-31 Walbro Corp Self-lift carburetor
US3556489A (en) * 1966-08-15 1971-01-19 Nippon Steel Corp Wet type gas scrubber
US3575390A (en) * 1968-05-24 1971-04-20 Acf Ind Inc Carburetion

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1093901A (en) * 1912-12-06 1914-04-21 Horace B Wyman Carbureter.
US1277963A (en) * 1914-10-22 1918-09-03 Ralph M Lovejoy Carbureter.
US2877003A (en) * 1955-06-22 1959-03-10 Acf Ind Inc Tangential nozzle type carburetor
US3214150A (en) * 1961-07-03 1965-10-26 Ohlsson & Rice Inc Carburetor
US3253822A (en) * 1964-03-09 1966-05-31 Walbro Corp Self-lift carburetor
US3556489A (en) * 1966-08-15 1971-01-19 Nippon Steel Corp Wet type gas scrubber
US3575390A (en) * 1968-05-24 1971-04-20 Acf Ind Inc Carburetion

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4211196A (en) * 1977-05-12 1980-07-08 Societe Pour L'equipement De Vehicules Carburetor
US4268462A (en) * 1979-01-18 1981-05-19 Nissan Motor Company, Limited Variable venturi carburetor

Also Published As

Publication number Publication date
DE2202616A1 (de) 1972-09-14
DE2202616C3 (de) 1981-11-26
DE2202616B2 (de) 1981-04-23
CA950291A (en) 1974-07-02
FR2127646A5 (de) 1972-10-13
GB1344127A (en) 1974-01-16
AU3516871A (en) 1973-05-03

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