WO1981000593A1 - Carburateur simple etage - Google Patents

Carburateur simple etage Download PDF

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Publication number
WO1981000593A1
WO1981000593A1 PCT/US1979/000663 US7900663W WO8100593A1 WO 1981000593 A1 WO1981000593 A1 WO 1981000593A1 US 7900663 W US7900663 W US 7900663W WO 8100593 A1 WO8100593 A1 WO 8100593A1
Authority
WO
WIPO (PCT)
Prior art keywords
staging
lever
valve
open position
carburetor
Prior art date
Application number
PCT/US1979/000663
Other languages
English (en)
Inventor
S Dye
K Berkbigler
F Latz
Original Assignee
Acf Ind Inc
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 Acf Ind Inc filed Critical Acf Ind Inc
Priority to JP50036479A priority Critical patent/JPS56501168A/ja
Priority to BR7909031A priority patent/BR7909031A/pt
Priority to PCT/US1979/000663 priority patent/WO1981000593A1/fr
Publication of WO1981000593A1 publication Critical patent/WO1981000593A1/fr
Priority to EP19800900187 priority patent/EP0034584A4/fr

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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
    • 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
    • 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
    • F02M1/00—Carburettors with means for facilitating engine's starting or its idling below operational temperatures
    • F02M1/08—Carburettors with means for facilitating engine's starting or its idling below operational temperatures the means to facilitate starting or idling becoming operative or inoperative automatically
    • F02M1/10—Carburettors with means for facilitating engine's starting or its idling below operational temperatures the means to facilitate starting or idling becoming operative or inoperative automatically dependent on engine temperature, e.g. having thermostat

Definitions

  • This invention relates to carburetors and, more particularly, to a staged single barrel carburetor.
  • staged two barrel or staged dual carburetor over a conventional two
  • 20 barrel carburetor is that the staged two barrel carburetor is, in effect, two carburetors, i.e., a single barrel carburetor for low speed, low load conditions -in which fuel economy and reduced emissions are important and a two barrel carburetor for high speed, high load conditions in which
  • staged dual carburetors help improve fuel economy and reduce emissions, they do have disadvantages.
  • One of these is in the area of driveability. Specifically, there is
  • a single barrel carburetor the provision of such a carburetor having an air capacity com- parable to multi-barrel, e.g., two barrel carburetors; the provision of such a carburetor which is a staged carburetor and which achieves fuel economy and reduced engine emission during the normal driving range of an automobile and which has the performance capability needed for high speed, high load driving conditions; the provision of such a carburetor in which the transition in carburetor operation that occurs at staging is accomplished without engine lag or a momentar lapse in engine performance; the provision of such a carbure tor having an anterior valve in its throat which functions both as a choke valve during engine starting and engine warm up and as an air valve during other engine operating conditions; and the provisions of such a carburetor in whic this anterior or staging valve is responsive only to engine air demand to vary the air capacity of the carburetor.
  • a carburetor of the present invention is for an internal combustion engine and comprises a carburetor body in which an induction passage is formed for air to be drawn into the engine.
  • a throttle valve is positioned in the induction passage and is movable between an open and a closed position to control the quantity of air drawn into the engine.
  • a staging valve is positioned in the induction passage and is movable between an open and a closed position The staging valve is closed during cranking of the engine and is moved to a first open position when the engine starts and toward its fully open position as the engine warms up. Means are provided for limiting the opening movement of the staging valve to a second open position which is less than
  • _OMPI its fully open position.
  • the limiting of staging valve movement to this second and less than fully open position limits the usable air capacity of the carburetor to less than its maximum capacity.
  • Staging means increases the air capacity of the carburetor.
  • the staging means is responsive to movement of the throttle valve past a predetermined open position to allow the staging valve to move freely between its second open position and its fully open position solely in response to the demand for air by the engine. The free movement of the staging valve to its fully open position increases the usable air capacity of the carburetor to its maximum capacity.
  • Fig. 3 is a graph illustrating the functioning of. a carburetor of the present invention.
  • Fig. 4 is a graph illustrating the problem solved by a carburetor of the present invention.
  • Figs. 5-7 are simplified side elevational views, in section, of a carburetor of the present invention to aid in understanding operation of the carburetor.
  • Figs. 8 and 9 are front and side elevational views respectively of a second embodiment of a carburetor of the present invention, Fig. 9 being partly in section;
  • Figs. 10-12 are side elevational views of the second embodiment of the carburetor illustrating the operation of the carburetor in a manner similar to that shown in Figs. 5-7
  • Figs. 13 and 14 are front and side elevational views respectively of a third embodiment of a carburetor of the present invention, Fig. 14 being partly in section.
  • Figs. 15 and 16 are front and side elevational views of a fourth embodiment of a carburetor of the present invention, Fig. 16 being partly in section.
  • a carburetor for an interna combustion engine (not shown) is indicated generally C and is comprised of three parts: an air horn H, a throttle flange F, and a carburetor body B.
  • the carburetor is mounted on an intake manifold (not shown) of the engine, and a single air induction passage P (see Figs. 5-7) is formed in carburetor body B for air to be drawn into the engine.
  • carburetor C is commonly referred to as a single barrel carburetor.
  • the passage has a restricted section or venturi V to create a pressure drop in the passage and a boost venturi BV positioned in the passage at the venturi serves to increase the pressure drop.
  • Fuel from a carburetor fuel bowl (not shown) is delivered to the passage through a fuel circuit FC (a portion of whic is shown in Figs. 5-7) and discharged into the passage through a nozzle N.
  • the quantity of fuel discharged into the passage is a function of the pressure drop or nozzle signal created in the passage.
  • a throttle valve T is positioned in the induction passage, at its lower outlet end, and is movable between an open and a closed position to control the quantity of air drawn into the engine.
  • throttle valve T comprises a disk 1 mounted on a shaft 3 journalled for rotation.
  • a throttle lever 5 is secured to the outer end of shaft 3 and is rotatable with the shaft.
  • the throttle lever is connected to, for example, an accelerator pedal (not shown) operated by the driver of a vehicle in which the engine is installed so when the operator depresses the pedal, the throttle lever is rotated in a counterclockwise direction (as viewed in Fig. 2) to rotate shaft 3 and move the throttle valve from its closed position (see Fig. 5) through a series of intermediate open positions (for example the position shown in Fig. 6) to its fully open position (see Fig. 7).
  • an accelerator pedal not shown
  • a driver of a vehicle in which the engine is installed so when the operator depresses the pedal, the throttle lever is rotated in a counterclockwise direction (as viewed in Fig. 2) to rotate shaft 3 and move the throttle valve from its closed position (see Fig. 5) through a series of intermediate open positions (for example the position shown in Fig. 6) to its fully open position (see Fig. 7).
  • a staging valve S is positioned in the induction passag at its upper inlet end, and is movable between an open and a closed position. Referring to Figs. 5-7, the staging valve
  • staging valve S is unbalanced.
  • the staging valve is substantially closed during cranking of the engine so a suitably rich air-fuel mixture is supplied to the engine to start it.
  • Means, generally designated 11, move the staging valve from its substantially closed position to a first open posi- tion when the engine starts and toward its fully open position as the engine warms up.
  • Means 11 comprises a vacuum motor 13 and a thermostatic coil 15 (a portion of which is shown in Fig. 2) .
  • a lever 17 is secured to the outer end of staging valve shaft 9 and the lever has an arm 19 connected to a piston 21 of the vacuum motor by a link 23.
  • the piston is reciprocal in a cylinder 25 of the vacuum motor, the cylinder being subjected to engine vacuum via a passage (not shown) extending between the lower end of the cylinder and the engine intake manifold.
  • Choke lever 17 has a second and outwardly extending arm 27 and the outer end of coil 15 contacts arm 27 to urge the choke lever and the staging valve in a counterclockwise or staging valve closing direction.
  • moving means 11 is similar to that of a standard carburetor choke break. That is, when the engine is cold, coil 15 is .contracted and pulls the staging valve to its substantially closed position (i.e., the position SI shown in Figs. 2 and 5). When the engine starts, the vacuum present in cylinder 25 pulls piston 21 downward with an opening force which is sufficient to partially overcome the closing force exerted on choke lever 17 by the thermo ⁇ static coil and the choke lever rotates clockwise to move the staging valve to its first open or choke break position (i.e., position S2 in Fig. 5).
  • thermostatic coil 15 causes thermostatic coil 15 to expand and the end of the coil contacting arm 27 of the choke lever rotates clockwise as viewed in Fig. 2. Because staging valve S is unbalanced, it tends to rotate clockwise and the restraining force placed on this
  • Means 29 limits the opening movement of the s.taging valve to a second open position (the position S3 in Fig. 5) which is intermediate its first open position and its fully open position.
  • Means 29 includes a first lever LI which is secured to staging valve shaft 9 for rotation with the shaft.
  • the means further includes a second lever L2 which is a loose lever, i.e. it is rotatable about shaft 9.
  • Levers LI and L2 are so oriented with respect to each other that lever LI contacts Lever L2 as the staging valve opens and for this purpose, each lever has an inwardly projecting tab (tabs 31 and 33 respectively) .
  • lever L2 is positioned so as to be spaced apart from Lever LI, the spatial separa ⁇ tion corresponding to the degree of opening of staging valve S as it moves from its closed position to its second open position. As shown in Fig. 2, the position of lever L2 is clockwise from that of lever LI.
  • lever LI rotates in the clockwise direction and the separation between the levers decreases.
  • Lever L2 exerts sufficient force on lever LI so as to restrain, i.e. limit, further opening movement of the staging valve and it is constrained to its second open position.
  • staging valve S limits the usable air capacity of the carburetor. This is because staging valve S, when held at its second open position, acts as a partial obstruction to air being drawn into the engine through induction passage
  • a staging means, generally designated 35, increases the usable air capacity of the carburetor.
  • Means 35 includes a staging lever 37 rotatable about throttle valve shaft 3 and a staging link 39 connecting the stating lever with lever L2.
  • Link 39 forms a solid connection between the- stagin, lever and lever L2.
  • Staging lever 37 has an inwardly pro ⁇ jecting tang or arm 41 and throttle lever 5 has an inwardly projecting tang or arm 43.
  • a bias spring 45 urges staging lever 37 in a clockwise direction to position lever L2 with respect to lever LI so lever LI contacts lever L2 when the staging valve reaches its second open position.
  • throttle lever 5 When throttle valve T is closed, throttle lever 5 is spaced apart from staging lever 37 as shown in Fig. 2. As the throttle valve opens, this spatial separation decreases until tang 43 of the throttle lever bears against tang 41 of the staging lever. When this occurs, the throttle valve has reached a predetermined open position. As the throttle valve moves past this predetermined open position, the throttle lever pushes the staging lever in a counterclockwise direction and lever L2 is pulled in a clockwise direction away from lever LI. When this happens, staging of carburetor C occurs and staging valve S, which previously had functioned as a choke valve, now functions as an air valve. That is, the staging valve is allowed to move freely between its second open position S3 and its fully open position (position S4 in Fig.
  • the staging valve is freely movable to its wide open position and the free movement of the staging valve to its fully open position increases the usable air capacity of carburetor C to its maximum capacity.
  • the throttle lever is so oriented with respect to the staging lever that it does not contact the staging lever until the throttle valve moves past its pre- determined open position, any movement (opening or closing) of the throttle valve which does not move it past this posi ⁇ tion will not cause the lever L2 to be moved and the staging valve will continue to limit the usable air capacity of the carburetor.
  • a fast idle cam 45 is rotatable about a spindle 47 and has a slot 49 in which one end of a link 51 is received. The other end of the link is attached to fixed lever LI.
  • the fast idle cam has ' a contour surface 53 which is stepped and an adjustable screw 55 mounted on throttle lever 5 contacts this contour surface. As the throttle opens, the screw moves away from the contour surfa of the cam and the cam rotates, by gravity until the bottom of slot 49 contacts the lower end of link 51.
  • th function of fast idle cam 45 serves to block the throttle valve partly open while the engine is warming up to keep it from stalling out when the throttle valve is closed, i.e. when the engine idles.
  • carburetor C can be likened to that of a staged two barrel carburetor.
  • Two essentially parallel curves are shown in Fig. 3, each representing the plot of nozzle signal in inches (in.) of water versus air flow in pounds per minute (lbs/min) .
  • the curve SD on the left is equivalent to the curve for a carburetor having a small diameter air induction passage than that represented by the curve LD on the right.
  • throttle valve T does not open past its predetermined open position and the staging valve is limited to its second open positio
  • the response of the carburetor follows curve SD with limiting means 29 limiting the opening move ⁇ ment of the staging valve to a second open position in which the resultant air-fuel mixture produced in the carburetor and combusted in the engine has an air-fuel ratio at which engine fuel economy is maximized and engine emissions are minimized.
  • the cros-sectional area of induction passage P is comparable to the total cross-sectional area of the induction passage of a two barrel carburetor. This permits the maximum air capacity of carburetor C to be comparable to that of a two barrel carburetor.
  • the bore diameter of induction passage P is 1.5 inches (3.81 cm) and its maximum air capacity is 19 pounds of air per minute. This is comparable to the air capacity of presently available two barrel carburetors.
  • Curve V represents a carburetor having a maximum air capacity ' of 14 to 16 pounds of air (i.e. a carburetor such as that represented by curve SD in Fig. 3), and curve W represents the same carburetor having an obstruc tion which restricts air flow.
  • Staging valve S if restrained to its second open position throughout the opening movement of throttle valve T produces the effect shown in curve W.
  • Curve X represents a carburetor of larger capacity than that represented by curve V (i.e. a carburetor such as that represented by curve LD in Fig.
  • a second embodiment of carburetor C is indicated generally C2 with carburetor body B2 having an air induction passage P2 (see Figs. 10-12).
  • a throttle valve T2 positioned in the lower outlet end of the induction passage is comprised of a disk 201 mounted on a shaft 203 journalled for rotation and a throttle lever 205 is secured to one end of the throttle valve shaft for rotation with the shaft.
  • a staging valve 2S is positioned at the upper inlet end of the induction passage and comprises a disk 207 mounted on a shaft 209 journalled for rotation. Means 211 moves the staging valve from its substantially closed position (position Sl in Fig. 10) to a first open position (position S2 in Fig.
  • the moving means includes a vacuum motor 213 and a thermostatic coil 215 (a portion of which is shown in Fig. 9) .
  • a choke lever 217 is secured to the end of staging valve shaft 209 and the choke lever has an arm 219 connected to a piston 221 of the vacuum motor by a link 223.
  • the piston is reciprocal in a cylinder 225 which is sub ⁇ jected to engine vacuum when the engine starts.
  • the choke lever has a second and outwardly extending arm 227 which is contacted by the free end of thermostatic coil 215 as shown in Fig. 9. Operation of moving means 211 is the same as that of moving means 11 as previously described.
  • a means generally designated 229 limits the opening movement of the staging valve to a second open position (position S3 in Figs. 10 and 11) which is intermediate the first open position of the staging valve and its fully open position. As previously indicated, the limiting of the staging valve to this second and less than fully open posi ⁇ tion limits the usable air capacity of the carburetor.
  • Means 229 includes a lever L3 secured to staging valve shaft 209 for rotation with the shaft.
  • Lever L3 is an L-shaped lever, the base of which is attached to the staging valve shaft by a screw 231. The leg of lever L3 is slightly bent and the end of the leg is turned over on itself to form a receptacle.
  • a staging means 233 serves to Increase the usable air capacity of carburetor C2 and comprises a staging lever 235.
  • the staging lever has an elongate curved slot 237, sometimes referred to as a "banana" slot and a link 239 connects the staging lever with lever L3.
  • One end of link 239 is receive in slot 237 and the other end of the link is captured in the receptacle formed at the end of the vertical leg of lever L3.
  • the lower end of link 239 is positioned at the lower end of slot 237 when the staging valve is substantially closed and travels along the length of the slot as the staging valve opens and lever L3 rotates clockwise with the staging valve shaft.
  • the staging valve when this occurs is the second open posi ⁇ tion of the staging valve
  • a fast idle cam 241 is commonly mounted on a spindle 243 with staging lever 235 and the staging lever and the fast idle cam are independently rotatable about the spindle which serves as pivot for the staging lever.
  • Fast idle cam 241 has a slot 245 which is substantially identical in size and in registry with slot 237 and, as shown in Fig. 8, the lower outwardly porjecting end of link 239 extends through slot 245 and is received in slot 237.
  • the fast idle cam has a stepped contour surface 247 which is contacted by an adjustable screw 249 mounted on throttle lever 205. The functioning of fast idle cam 241 to hold throttle valve T2 open during engine idle is the same as previously described.
  • Staging means 233 is responsive to the opening of throttle valve T2 past a predetermined open position to enable the staging valve to move freely between its second open position and fully open position solely in response to demand for air by the engine. Again, this free movement of the staging valve to its fully open position increases the usable air capacity of the carburetor to its maximum capacity.
  • Throttle lever 205 has a rearward extension or ear 250 and the staging means further comprises a staging link 251 connecting the throttle lever with the staging lever.
  • the staging lever has a second slot 253 which is on the opposite end of the lever from slot 237. As shown in Figs.
  • this second slot is somewhat shorter than slot 237, but the length of this second slot is a function of the predetermined open position past which the throttle valve moves before the throttle lever produces rotation of the staging lever and staging of the carburetor occurs.
  • One end of staging link 251 is captured in ear 250 and the other end of the link is received in slot 253.
  • the link is slightly bent as indicated in the drawings in order for its respective ends to be fitted in their respective receptacles.
  • a spring 255 has one end received in staging lever 235 and its other end received in an outwardly extending projection of the carburetor air horn. The spring urges the staging lever in a counterclockwise direction, as viewed in Figs. 9-12, so a tang or finger 257 of the staging lever bears against a stop 259.
  • a spring 261 is installed in a housing 263 in which the thermostatic coil 215 and vacuum motor 213 of moving means 211 are housed.
  • Spring 261 is formed of a piece of bendable spring material which is partially coiled so the spring has a coiled center section and two oppositely extending arms, one of which is longer than the other. The coiled section of the spring fits over a hub 265 extending outwardly from the rear wall of the housing.
  • the hub is located near the bottom of the housing and the shorter arm of the spring bears against the side of the housing.
  • the longer arm of the spring extends upwardly and approximately midway along its length bears against the inside of a pedestal 267 which extends outwardly from the rear wall of the housing.
  • the function of the pedestal is to preload the spring and constrain it from rotating in a counterclock ⁇ wise direction as viewed in Fig. 9.
  • Outwardly extending arm 227 of choke lever 217 (the arm of the choke lever contacting the outer end of thermostatic coil 215) contacts the outer end of the longer arm of spring 261, as the staging valve moves to its fully open position, and pushes it in a clockwise direction away from the side of pedestal 267.
  • the closing force exerted on the staging valve by spring 261 is less than the opening force exerted on the staging valve as engine air demand increases, but when the staging valve is near or at its fully open position and the demand for air by the engine decreases, the force exerted on the choke lever by the spring is sufficient to overcome the opening force exerted on the staging valve by the engine's manifold vacuum and the air being drawn into the engine and the staging valve shaft is rotated clockwise until the staging valve reaches the position S5 shown in Fig. 12. At this position, the longer arm of spring 261 again bears against the side of pedestal 267. It will be understood that spring 261 may also be installed in the- housing of carburetor C in which thermo ⁇ static coil 15 and vacuum motor 13 are housed and that the spring, hub, and pedestal are not shown in Fig. 2 only for the sake of drawing clarity..
  • a third embodiment of a carburetor C of the present invention is. similar to that of the embodiment shown in Figs. 8-12 except for differences in the staging means.
  • limiting means 229' comprises a lever L3' which is secured to staging valve shaft 209 for rotation with the shaft.
  • a staging means 269 comprises a staging lever 271 commonly mounted on spindle 243 with fast idle cam 241.
  • a link 273 connects the staging lever with lever L3'.
  • the staging lever has an elongate curved slot 275 in which the lower end of link 273 is received and, as shown in Fig. 13, the lower end of the link extends through slot 245 in fast idle cam 241 as well as being received in slot 275.
  • the movement of link 273 in slot 275 as the staging valve moves from its closed to its first open position and then toward its fully open position is the same as previously described with respect to the operation of staging means 233.
  • a coil spring 277 fits over spindle 243 and urges the staging lever in a counterclockwise direction so a finger 279 of the stagi lever bears against an adjustable stop 281. By adjusting the position of stop 281, the second open position to which opening movement of the staging valve is limited is adjusted.
  • the end of the staging lever opposite finger 279 is U-shaped, as seen in Fig. 13, and a plate 283 is fitted within the U.
  • a staging link 285 has one end secured to throttle lever
  • the staging link 205' and the other end of the staging link extends upwardly through an opening in the plate.
  • This latter end of the staging link is threaded for a collar 287 to be attached to the link.
  • the collar is larger than the opening in plate 283 and the spatial separation between the bottom surface of the collar and the upper surface of the plate corresponds to the predetermined open position to which the throttle valve moves before the staging valve is freed to move between its second open position and its fully open position in response to engine air demand.
  • a fourth embodiment of a carburetor of the present invention is indicated C4 and comprises a body B4 in which an air induction passage P4 is formed.
  • a throttle valve T4 is positioned at the lower outlet end of the induction passage and includes a disk 401 mounted on a shaft 403 journalled for rotation.
  • a throttle lever 405 is secured to the outer end of shaft 403 for rotation with the shaft.
  • a staging valve 4S is positioned at the upper inlet end of the induction passage and includes a disk 407 mounted on a shaft 409 journalled for rotation. As before, the staging valve is substantially closed during cranking of the engine so a suitably rich air-fuel mixture is supplied to the engine to start it.'
  • a means 411 moves the staging valve to a first open position when the engine starts and toward its fully open position as the engine warms up.
  • the moving means comprises a thermostatic coil 413 installed in a housing 415 and a vacuum motor (not shown) which is external to the housing.
  • a choke lever 417 has an arm 419 contacting the free end of the thermostatic coil.
  • a fast idle cam 441 controls the degree of throttle valve closing during engine idle and the cam has a stepped contour surface 447 contacted by an adjustable screw 449 attached to throttle lever 405.
  • the cam is rotatable about a spindle 443 to change the portion of the contour surface in contact with the throttle lever and thereby the degree of throttle valve closing, all as discussed hereinabove.
  • a limiting means 429 limits the opening movement of the staging valve to a second open position which is inter ⁇ mediate its first open position and its fully open position.
  • the limiting means includes a lever L4 which is secured to shaft 409 and rotates with the shaft. As seen in Fig.
  • a second lever L5 is rotatable about shaft 409 and includes a collar 431 which fits over the end of shaft 429 and choke lever 417 rigidly fits on the outer end of this collar.
  • a coil spring 432 fits over shaft 409 and one end of the spring bears against choke lever arm 419 to urge the choke lever in a clockwise direction as seen in Fig. 16.
  • Limiting means 429 includes a means 433 linking moving means 411 with fast idle cam 441 to control the movement of the fast idle cam and the portion of its contour surface in contact with the fast idle cam.
  • Lever L5 has an arm 435 and the linking means includes a link 437 connecting the lever and the fast idle cam.
  • the upper end of the link is attached to arm 435 of lever L5 and the lower end of the lin is received in a fast idle cam slot 445.
  • Slot 445 is an elongate curved slot in which the lower end of link 437 is movable and this lower end of the link is at the bottom end of the slot when the staging valve is closed. At that posi ⁇ tion, the link prevents rotation of the fast idle camabout its pivot when the throttle lever moves away from surface 447 of the cam.
  • Lever L4 has an arm 439 to which is attache a link as described hereinafter.
  • the vacuum motor is linked to lever L4 and, specifically, the vacuum motor which may, for example, be a diaphragm motor of the type well known in the art, has a stem (not shown) received in a slot 450 on the opposite side of the lever from arm 439.
  • a staging means 451 comprises a staging lever 453 which is a split lever having two portions 455 and 457, respective ly, which are movable relative to each other. Each portion of the lever is rotatable about spindle 443 and lever portio 455 has a contact surface 459 which is contacted by an adjustable screw 461 carried by portion 457 of the lever.
  • the staging means further includes a link 463 connecting lever L4 with the staging lever. The upper end of the link
  • Q PI is attached to arm 439 of lever L4 and the lower end of the link is received in an elongate curved slot 465 in staging lever portion 455.
  • slots 445 and 465 are sub ⁇ stantially identical in size and are in registry.
  • link 463 is shown at the top of slot 465 and link 437 at the bottom of slot 445 for ease of understanding only.
  • the staging lever is biased in a counter ⁇ clockwise direction by a spring (not shown) so a finger 467 of the staging lever bears against an adjustable stop 469. By adjusting the position of the stop, the second open position to which the staging valve is allowed to move is adjusted.
  • a staging link 471 forms a solid connection between throttle lever 405 and portion 457 of the staging lever.
  • lever L4 moves the lower end of link 463 part way up slot 465 of staging lever 453, but lever L5 remains stationary and the lower end of link 437 remains at the bottom of slot 445.
  • fast idle cam 441 is inhibited from rotating if throttle valve T4 is opened at this time.
  • the closing force exerted on choke lever 417 by thermostatic coil 413 is greater than the force exerted on the lever by spring 432, but as the engine warms this force gradually decreases and spring 432 urges the lever L5 assembly clockwise to move the staging valve toward its fully open position.
  • both levers L4 and L5 move with the valve and both links 463 and 437 move upward in their respective slots.
  • the staging lever now moves as a solid piece in a clockwise direction. Slot 465 of the staging lever moves relative to the lower end of link 463 and the staging valve is allowed to freely move between its second open position and its fully open position solely in response to demand for air by the engine. It will be noted that by adjusting screw 461, the predetermined distance past which the throttle valve must open before the staging valve is freed to move is adjustable.
  • the carburetor of the present invention is readily adaptable from an existing carburetor with a few changes, for example, removing a secondary boost venturi from the carburetor's air induction passage. How ⁇ ever, it is also important to note that the capabilities and advantages of the carburetor of this invention reside in the use of a staging valve which, in effect, functions as a choke valve a portion of the time and as an ari valve the rest of the time.
  • the position Sl of the staging valve is, for example, approximately 15° below the horizontal position of the valve.
  • the second open position (position S3) to which staging valve movement is limited is, for example, approximately 55 from the horizontal position of the staging valve, so the valve functions as a choke valve for approximately 40° of its opening movement.
  • the staging valve is allowed to function as an air valve the 35 of its travel between its second open position and its fully open position (position S4) .
  • the position past which the throttle valve must move before the staging valve is allowed to function as an air valve is, as described, variable, However, the degree of opening may correspond, for example, to a 6 to 8 pound of air per minute demand by the engine.

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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)
  • Means For Warming Up And Starting Carburetors (AREA)

Abstract

Un carburateur (C) possede un passage d'induction (P) et un papillon (T) dispose dans le passage d'induction. Une soupape d'etagement (S), egalement disposee dans le passage d'induction est fermee pendant la mise en route d'un moteur, ce qui permet une alimentation appropriee en un melange air-combustible du moteur pour le faire demarrer. La soupape d'etagement se deplace vers une premiere position ouverte lorsque le moteur demarre et vers une position grande ouverte au fur et a mesure que le moteur chauffe. Des moyens (29) limitent le mouvement d'ouverture de la soupape d'etagement sur une seconde position ouverte qui est intermediaire entre sa premiere position ouverte et sa position grande ouverte. Ceci limite la capacite utilisable d'air du carburateur. Des moyens d'etagement (35) sensibles au mouvement du papillon au-dela d'une position ouverte predeterminee permettent a la soupape d'etagememt de se deplacer librement entre sa seconde position ouverte et une position plus ouverte seulement en reponse a la demande en air du moteur. La soupape d'etagement peut se deplacer librement vers sa position grande ouverte lorsque le papillon est totalement ouvert et ceci augmente la capacite utilisable d'air du carburateur jusqu'a son maximum.
PCT/US1979/000663 1979-08-29 1979-08-29 Carburateur simple etage WO1981000593A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP50036479A JPS56501168A (fr) 1979-08-29 1979-08-29
BR7909031A BR7909031A (pt) 1979-08-29 1979-08-29 Carburador de estagio unico
PCT/US1979/000663 WO1981000593A1 (fr) 1979-08-29 1979-08-29 Carburateur simple etage
EP19800900187 EP0034584A4 (fr) 1979-08-29 1981-03-09 Carburateur simple etage.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
WOUS79/00663 1979-08-29
PCT/US1979/000663 WO1981000593A1 (fr) 1979-08-29 1979-08-29 Carburateur simple etage

Publications (1)

Publication Number Publication Date
WO1981000593A1 true WO1981000593A1 (fr) 1981-03-05

Family

ID=22147683

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1979/000663 WO1981000593A1 (fr) 1979-08-29 1979-08-29 Carburateur simple etage

Country Status (4)

Country Link
EP (1) EP0034584A4 (fr)
JP (1) JPS56501168A (fr)
BR (1) BR7909031A (fr)
WO (1) WO1981000593A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2640692A1 (fr) * 1988-12-21 1990-06-22 Stihl Andreas Carburateur a membrane comportant un papillon des gaz et un volet de depart couples de facon a etre interdependants dans leur position

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US1456502A (en) * 1919-02-12 1923-05-29 Auto Betterment Corp Carburetor for internal-combustion engines
US1838421A (en) * 1929-07-11 1931-12-29 Wheelerschebler Carburetor Com Down draft carburetor
US2082710A (en) * 1935-12-05 1937-06-01 Mallory Marion Carburetor
US2195867A (en) * 1937-04-14 1940-04-02 Mallory Marion Carburetor
US2198676A (en) * 1938-04-28 1940-04-30 Mallory Marion Carburetor
US2557111A (en) * 1943-10-22 1951-06-19 Gen Motors Corp Charge forming device
US2694558A (en) * 1949-11-03 1954-11-16 Gen Motors Corp Charge forming device
US2857146A (en) * 1956-03-01 1958-10-21 Acf Ind Inc Secondary throttle control for multi-stage carburetor
US2943848A (en) * 1958-10-06 1960-07-05 Acf Ind Inc Separate thermostat controlled fast idle cam
US3043572A (en) * 1959-07-13 1962-07-10 Acf Ind Inc Separate thermostat controlled latch mechanism for secondary throttles
US3248095A (en) * 1961-12-21 1966-04-26 Chrysler Corp Choke control for carburetor
US3249344A (en) * 1963-05-17 1966-05-03 Acf Ind Inc Carburetor
US3309069A (en) * 1964-05-13 1967-03-14 Ford Motor Co Mechanism for a constant metering force carburetor
US3322408A (en) * 1965-09-01 1967-05-30 Gen Motors Corp Carburetor
US3886917A (en) * 1972-07-13 1975-06-03 Toyota Motor Co Ltd Carburetor with automatic choke
US4119684A (en) * 1976-10-06 1978-10-10 Hitachi, Ltd. Variable stage type carburetor

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Publication number Priority date Publication date Assignee Title
US2741466A (en) * 1953-07-15 1956-04-10 Holley Carburetor Co Carburetor

Patent Citations (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1456502A (en) * 1919-02-12 1923-05-29 Auto Betterment Corp Carburetor for internal-combustion engines
US1838421A (en) * 1929-07-11 1931-12-29 Wheelerschebler Carburetor Com Down draft carburetor
US2082710A (en) * 1935-12-05 1937-06-01 Mallory Marion Carburetor
US2195867A (en) * 1937-04-14 1940-04-02 Mallory Marion Carburetor
US2198676A (en) * 1938-04-28 1940-04-30 Mallory Marion Carburetor
US2557111A (en) * 1943-10-22 1951-06-19 Gen Motors Corp Charge forming device
US2694558A (en) * 1949-11-03 1954-11-16 Gen Motors Corp Charge forming device
US2857146A (en) * 1956-03-01 1958-10-21 Acf Ind Inc Secondary throttle control for multi-stage carburetor
US2943848A (en) * 1958-10-06 1960-07-05 Acf Ind Inc Separate thermostat controlled fast idle cam
US3043572A (en) * 1959-07-13 1962-07-10 Acf Ind Inc Separate thermostat controlled latch mechanism for secondary throttles
US3248095A (en) * 1961-12-21 1966-04-26 Chrysler Corp Choke control for carburetor
US3249344A (en) * 1963-05-17 1966-05-03 Acf Ind Inc Carburetor
US3309069A (en) * 1964-05-13 1967-03-14 Ford Motor Co Mechanism for a constant metering force carburetor
US3322408A (en) * 1965-09-01 1967-05-30 Gen Motors Corp Carburetor
US3886917A (en) * 1972-07-13 1975-06-03 Toyota Motor Co Ltd Carburetor with automatic choke
US4119684A (en) * 1976-10-06 1978-10-10 Hitachi, Ltd. Variable stage type carburetor

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP0034584A4 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2640692A1 (fr) * 1988-12-21 1990-06-22 Stihl Andreas Carburateur a membrane comportant un papillon des gaz et un volet de depart couples de facon a etre interdependants dans leur position

Also Published As

Publication number Publication date
EP0034584A1 (fr) 1981-09-02
BR7909031A (pt) 1981-06-23
JPS56501168A (fr) 1981-08-20
EP0034584A4 (fr) 1982-03-10

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