US3202403A - Return flow carburetor - Google Patents
Return flow carburetor Download PDFInfo
- Publication number
- US3202403A US3202403A US254875A US25487563A US3202403A US 3202403 A US3202403 A US 3202403A US 254875 A US254875 A US 254875A US 25487563 A US25487563 A US 25487563A US 3202403 A US3202403 A US 3202403A
- Authority
- US
- United States
- Prior art keywords
- fuel
- bowl
- conduit
- chamber
- conduit means
- 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
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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
- F02M17/00—Carburettors having pertinent characteristics not provided for in, or of interest apart from, the apparatus of preceding main groups F02M1/00 - F02M15/00
- F02M17/02—Floatless carburettors
- F02M17/06—Floatless carburettors having overflow chamber determining constant fuel level
-
- 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
- F02M7/06—Means for enriching charge on sudden air throttle opening, i.e. at acceleration, e.g. storage means in passage way system
- F02M7/08—Means for enriching charge on sudden air throttle opening, i.e. at acceleration, e.g. storage means in passage way system using pumps
Definitions
- a float controlled fuel inlet needle valve is employed to regulate the fuel level in the carburetor fuel bowl.
- Small dirt particles sometimes interfere with effective operation of the valve, as for example by becoming lodged between mating valve seats which otherwise cooperate to regulate the fuel flow into the fuel bowl.
- the floats require considerable size in order to be effective because of the comparatively low specific gravity of the fuel. In consequence the size of the fuel bowl must be appreciably larger than is otherwise desired.
- An important object of the present invention is to provide an improved carburetor which avoids the foregoing objections and in particular to provide a floatless carburetor which does not require a fuel inlet needle valve.
- Another object is to provide such a construction including an overflow standpipe in the fuel bowl having an upper opening which determines the maximum fuel level in the bowl.
- a fuel inlet pump is provided to pump fuel into the bowl at a rate in excess of demand. The excess fuel overflows into the standpipe and is returned to th fuel tank.
- a scavenging pump is provided in the fuel return line between the overflow standpipe and the tank.
- a fuel inlet pump which delivers an excess supply of fuel to the fuel bowl during all operating conditions of the engine.
- the throttle is suddenly closed while the engine is still operating at high speed, unless some provision is made to the contrary, approximately 98% of the fuel supplied to the fuel bowl will be recirculated, whereas approximately only 2% of the fuel will be used by the engine.
- the life of a fuel pump and in particu lar the life of an engine driven diaphragm type pump which is preferred for supply fuel in the quantity re quired and at a substantially uniform pressure regardless of changes in engine speed, depends upon the quantity of fuel pumped.
- another object of the present invention is to provide improved simple and highly effective means for supplying fuel to the fuel bowl in reasonable and safe amounts related to engine requirements.
- Another object is to provide a bypass conduit which extends from the discharge side of the fuel supply pump to the inlet side of the pump and which contains a suitable valve adjustable in response to variations in engine load for controlling the fuel flow in the bypass conduit.
- FIGURE 1 is a schematic mid-sectional view of a return flow carburetor and pump embodying the present invention.
- FIGURE 2 is a view similar to FIGURE 1 illustrating a modification.
- the carburetor shown comprises a cast housing formed to provide an air inlet induction conduit including a venturi portion it) having a restricted venturi if at its upper portion and a throttle blade 12 pivotally mounted on a shaft 13 at a lower portion usually referred to as the throttle body.
- An upper portion of the casting is formed to provide an air born 14 adapted to be connected with the usual air filter and opening at its downstream end into the venturi 11 to supply air thereto.
- the casting portions ill and 14 are suitably secured together, as for example by screws not shown, and comprise an upper portion of the air inlet and fuel mixing induction system which extends downstream of the throttle valve 12 and discharges into the usual engine cylinders in a conventional manner.
- a fuel bowl casting 15 containing an annular chamber or fuel bowl 116 enclosing a cylindrical standpipe or weir 17 which also serves as an acceleration pump cylinder containing a plunger 18 reciprocable in its lower portion and secured to a plunger shaft 19 for actuation thereby.
- the shaft 19 is connected by suitable linkage with a pedal operated accelerator mechanism. which controls the opening and closing of valve 12 to operate conjointly therewith.
- fuel is drawn into the lower portion of chamber 17 via conduit 29 in communication with the bowl 16.
- a suitable check valve illustrated schematically as a ball check element 21 normally seats at the mouth of the duct 26 opening into the lower portion of chamber 17 to prevent loss of fuel therefrom but is raised from its seat by the fuel flow into chamber 17 on the upstroke of plunger 18.
- the check valve 23 is schematically illustrated as a ball normally urged by a spring to a seated position 0 closing nozzle 24 from the interior of chamber 17, the
- the main Y16 and communicates at its upper end with a fuel nozzle 27 having its discharge orifice located within the throat of venturi 11. f
- a multiple piece fuel pump housing 37 comprising an upper dome 38 and a lower basin 39 cooperate with diaphragrns 40 and 41 respectively to provide an inlet fuel pumping or working'chamber 42 and an exhaust fuel pumping or scavenging chamber 43.
- Springs 44 and 45 under compression between portionsof housing 37 and diaphragms 40 and 41 respectively urgethe former dia phragmupwardly and the latter diaphragm downwardly to effect-the pumpingstrokes for the respective chambers 42 and 43.
- the upper working-chamber 42 comprises a portion of supply duct 28 whichcommunicates upstream'of chamber 42 with the fuel tank 28b.
- Fuel enters and leaves 'chamber 42 via an inlet 'port 46 and a discharge port 47 associated with check valves 48 and 49 respectively.
- inlet 'port 46 Upon downward movement of diaphragm 40 as explained below, fuel is drawn in the direction of the arrow 28a from the tank and-through inlet port 46 into working chamber ;42.
- ball valve 48 is forced fromv its seat at port 46 by the fuel flow, and ball 'valve49- seats at the discharge port 47 to close'the latter "from the fuel bowl 16.
- 'Ball check valves 55 and 56 are associated with ports 53 and 54 respectively; so that of thediaphragms 40 and 41 opposite chambers 42 and :Videdwvhich communicates at opposite ends with the discharge and inlet sides of chamber 42 respectively at lo "cations downstream ofport 47 andupstream of 'port 46.
- "Avalving port or orifice 29 in conduit'42a is controlled 'bya taperedneedle valve 31registering'with port 29 at the latters high pressure side and connected to the underside of a flexible diaphragm 32. Upon downward .movement of valve 31, orifice 29 is progressively restricted to reduce the fuel flow therethrough as described below.”
- the diaphragm 32 is confined within a pressure chamber 33 and.
- the chamber part above diaphragm32 is connected by a pressure duct 35 to theinductioncohduit at a point adjacent and downstream of the throttle valve 12.
- V V i Actuation of the diaphragm. 40 and 41 is accomplished by driving shafts 57 and 58 connected to these dia phragms and terminating in enlarged heads 59 and 60 respectively.
- Pivotal levers 61 and 62 are pivoted on housing 37 at locations 63 and 64' respectively between their ends.
- Each lever has one end engaged with a rotating eccentric cam 65 mounted on a shaft 66 driven by the automobile engine.
- the opposite ends of the levers 61'and 62 are provided with oversiz'ed openings 67 and 68 through which the rods 57 and 58 extend freely to enable their relative sliding movement with respect to the levers 61 and 62 until the levers engage the enlarged heads 59 and 6d.
- shaft 66 Upon operation of the automobile engine, shaft 66 is rotated to turn eccentric cam 65 and thereby cause pivot ing of levers 61 and 62, Upon clockwise pivoting of lever 61, or counterclockwise pivoting of lever 62, the head 59 or 66 is engaged to pull the associated rod 57 and 58 in the direction to compress the spring'44 and J 45 as the case might be. Uponcounterclockwise pivoting of lever 61 and clockwise pivoting of lever 62, the
- oversized openings 67 and 68 enable the levers to swing independently of the shafts 57 and 58, whereupon springs 44 and 45 are released to force diaphragms'42 and 43 in pumping actions toward the associated dome 38 or basin 39.
- the pivotal action of levers 61 and 62 merely compresses the springs 44 and 45 alternately, which latter then '17 and returns by conduit 52 to chamber 43 via port .53,
- conduit '35 which progressively increases the pressure in chamber33 above diaphragm 32 as valve 12 is pivoted .toward a wide open position, i.e., as engine load increases.
- the resistance to fuel flow in conduit 28 downstream of bypass conduit 42a is preferably greater than the corresponding resistance in bypass conduit 42a and is predetermined, as for example by a restricted orifice 3b, in order to assure adequate fiuid flow in bypass conduit 42:: when valve 31 opens.
- FIGURE 1 provides means for supplying fuel to bowl 16 at a rate which is a function of engine load, the vacuum induced force below valve 12 is at its maximum at low engine load and progressively decreases as engine load increases. Accordingly, at comparatively high engine load when the throttle valve 12 is open fully or nearly so, that vacuum force acting on diaphragm 32 is a minimum and changes in the throttle position result in comparatively low magnitude pressure changes on diaphragm 32.
- FIGURE 2 Where increased effectiveness of the vacuum induced force at high engine load is desired, a construction such as illustrated in FIGURE 2 is preferred.
- the general arrangement of the return flow carburetor and pump is the same in FIGURE 2 as in FIGURE 1 so that identical parts are numbered the same in both drawings.
- the distinction of FIGURE 2 is that conduit 35 is replaced by conduit 69, and needle valve 31 is replaced by a tapered valve 7:) registering with the low pressure side of orifice 29 and having a stem secured to diaphragm 32.
- Conduit 69 connects chamber 33 above diaphragm 32 with the induction conduit at a location adjacent the throat of the venturi 11. Accordingly as engine load increases, the vacuum induced force at the throat of venturi 11 increases and becomes a maximum at wide open throttle.
- the resulting low pressure above diaphragm 32 enables the atmospheric pressure on the underside of the diaphragm to urge the latter upwardly against the force of spring 34 and move valve 70 toward orifice 29 to increase the restiiction thereof.
- the vacuum induced force above diaphragm 32 decreases, enabling spring 34 to move valve 7% downwardly and decrease the restriction at orifice 29, thereby to increase the bypass how in conduit 42a and to reduce the fuel flow into bowl 16.
- a fioatless fuel bowl for an internal combustion engine having a fuel and air induction system, a fioatless fuel bowl, duct means connecting said bowl and system, a fuel pump having an inlet and an outlet, first conduit means connecting said outlet with said fuel bowl for supplying fuel to the latter upon operation of said pump, means for maintaining the fuel in said bowl at a predetermined level comprising an overflow weir in said bowl defining at least in part a chamber adapted to receive excess fuel overflowing said weir from said boWl when the fuel in said bowl attains said predetermined level, fuel return means for returning excess fuel from said chamber to said inlet including a fuel return conduit in communication with said chamber to drain fuel therefrom upon overflow of excess fuel thereinto from said bowl, means for diverting a portion of the fuel in said first conduit means from said fuel bowl and system including bypass conduit means connecting said first conduit means with said fuel return means, means for proportioning the fuel flow from said fuel pump to said bowl and bypass conduit means including a predetermined restriction in said first conduit means at a location between
Description
Claims (1)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US254875A US3202403A (en) | 1959-06-05 | 1963-01-30 | Return flow carburetor |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US818349A US3098885A (en) | 1959-06-05 | 1959-06-05 | Return flow carburetor |
US254875A US3202403A (en) | 1959-06-05 | 1963-01-30 | Return flow carburetor |
Publications (1)
Publication Number | Publication Date |
---|---|
US3202403A true US3202403A (en) | 1965-08-24 |
Family
ID=26944294
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US254875A Expired - Lifetime US3202403A (en) | 1959-06-05 | 1963-01-30 | Return flow carburetor |
Country Status (1)
Country | Link |
---|---|
US (1) | US3202403A (en) |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1881860A (en) * | 1930-01-24 | 1932-10-11 | Stewart Warner Corp | Fuel pump |
US2136959A (en) * | 1934-10-26 | 1938-11-15 | Edward A Winfield | Fuel supply system |
US2409965A (en) * | 1944-04-10 | 1946-10-22 | George M Holley | Fuel pump |
US2691509A (en) * | 1950-03-31 | 1954-10-12 | Rivoche Eugene | Method and apparatus for supplying fuel |
US2874944A (en) * | 1957-06-05 | 1959-02-24 | Gen Motors Corp | Charge forming means |
US3127453A (en) * | 1959-03-23 | 1964-03-31 | Chrysler Corp | Floatless carburetor |
-
1963
- 1963-01-30 US US254875A patent/US3202403A/en not_active Expired - Lifetime
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1881860A (en) * | 1930-01-24 | 1932-10-11 | Stewart Warner Corp | Fuel pump |
US2136959A (en) * | 1934-10-26 | 1938-11-15 | Edward A Winfield | Fuel supply system |
US2409965A (en) * | 1944-04-10 | 1946-10-22 | George M Holley | Fuel pump |
US2691509A (en) * | 1950-03-31 | 1954-10-12 | Rivoche Eugene | Method and apparatus for supplying fuel |
US2874944A (en) * | 1957-06-05 | 1959-02-24 | Gen Motors Corp | Charge forming means |
US3127453A (en) * | 1959-03-23 | 1964-03-31 | Chrysler Corp | Floatless carburetor |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: FIDELITY UNION TRUST COMPANY, 765 BROAD ST., NEWAR Free format text: MORTGAGE;ASSIGNOR:CHRYSLER CORPORATION;REEL/FRAME:003832/0358 Effective date: 19810209 Owner name: FIDELITY UNION TRUST COMPANY, TRUSTEE,NEW JERSEY Free format text: MORTGAGE;ASSIGNOR:CHRYSLER CORPORATION;REEL/FRAME:003832/0358 Effective date: 19810209 |
|
AS | Assignment |
Owner name: CHRYSLER CORPORATION, HIGHLAND PARK, MI 12000 LYNN Free format text: ASSIGNORS HEREBY REASSIGN, TRANSFER AND RELINQUISH THEIR ENTIRE INTEREST UNDER SAID INVENTIONS AND RELEASE THEIR SECURITY INTEREST.;ASSIGNORS:FIDELITY UNION BANK;ARNEBECK, WILLIAM, INDIVIDUAL TRUSTEE;REEL/FRAME:004063/0604 Effective date: 19820217 |