US3897765A - Carburetor cranking fuel flow rate control - Google Patents

Carburetor cranking fuel flow rate control Download PDF

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Publication number
US3897765A
US3897765A US430819A US43081974A US3897765A US 3897765 A US3897765 A US 3897765A US 430819 A US430819 A US 430819A US 43081974 A US43081974 A US 43081974A US 3897765 A US3897765 A US 3897765A
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Prior art keywords
fuel
passage
flow
cranking
valve
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US430819A
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English (en)
Inventor
Robert S Harrison
John D Medrick
Alvin P Nowroski
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Ford Motor Co
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Ford Motor Co
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Priority to US430819A priority Critical patent/US3897765A/en
Priority to CA216,274A priority patent/CA1036441A/en
Priority to AU76457/74A priority patent/AU479388B2/en
Priority to GB5530474A priority patent/GB1475008A/en
Priority to DE19742461277 priority patent/DE2461277A1/de
Priority to JP49149078A priority patent/JPS5834664B2/ja
Application granted granted Critical
Publication of US3897765A publication Critical patent/US3897765A/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
    • F02M1/00—Carburettors with means for facilitating engine's starting or its idling below operational temperatures
    • F02M1/04—Carburettors with means for facilitating engine's starting or its idling below operational temperatures the means to facilitate starting or idling being auxiliary carburetting apparatus able to be put into, and out of, operation, e.g. having automatically-operated disc valves
    • F02M1/046—Auxiliary carburetting apparatus controlled by piston 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
    • 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
    • F02M9/00—Carburettors having air or fuel-air mixture passage throttling valves other than of butterfly type; Carburettors having fuel-air mixing chambers of variable shape or position
    • F02M9/10—Carburettors having air or fuel-air mixture passage throttling valves other than of butterfly type; Carburettors having fuel-air mixing chambers of variable shape or position having valves, or like controls, of elastic-wall type for controlling the passage, or for varying cross-sectional area, of fuel-air mixing chambers or of the entry passage
    • F02M9/106—Pneumatic or hydraulic control

Definitions

  • CARBURETOR CRANKING FUEL FLOW RATE CONTROL inventors Robert S. Harrison, Grosse lle; John D. Medrick, Madison; Alvin P. Nowroski, Livonia, all of Mich.
  • the extra fuel is supplied by a connection to a fuel reservoir past first, a flow rate control valve, and second, past a solenoid controlled valve that opens in response to closing of the engine starter relay to permit the induction of the extra fuel during engine cranking.
  • a temperature responsive member is included to break the circuit above say 125F., for example, to the solenoid.
  • the flow rate control valve is moved by a temperature responsive element to pro gressively restrict or unblock the fuel passage entrance, thereby varying the rate of flow with temperature changes.
  • CARBURETOR CRANKING FUEL FLOW RATE CONTROL This invention relates to a motor vehicle carburetor and more particularly to a system for supplying cranking fuel to the engine.
  • a conventional downdraft carburetor has an idle speed channel that bypasses the induction passage around the throttle valve to permit a supply of fuel and air when the throttle valve is closed, such as during engine idling speeds and starting.
  • a choke valve is rotated towards a closed position as a function of temperature changes to restrict the air inlet and thereby draw in the richer mixture necessary for cranking at these temperatures.
  • This invention relates to a variable area venturi carburetor in which at least one wall of the venturi is moved to enlarge the venturi. Tapered fuel metering rods attached to the movable wall are withdrawn from fuel jets to simultaneously change fuel flow.
  • the engine cranking position and idle speed position of the venturi are the same, and this type of carburetor has no choke valve. However, it is still necessary during cold engine operation, to supply the carburetor with extra fuel and in amounts that increase as the temperature drops.
  • cranking fuel system for a carburetor that is operative below a predetermined temperature to supply quantities of fuel to the carburetor that are in addition to whatever fuel may be inducted in the normal manner.
  • Another object of the invention is to provide a carburetor cold weather operating cranking fuel system that is operative when the engine ignition is turned to an engine start position below a predetermined temperature to energize a solenoid to unblock a fuel passage and permit the induction of additional quantities of fuel to the engine, the rate of supply being controlled by means of a tapered valve move as a function of temperature changes.
  • FIG. 1 is a plan view of a portion of a variable area venturi type carburetor embodying the invention
  • FIG. 2 is a side elevational view taken on a plane indicated by and viewed in the direction of the arrows 22 of FIG. 1;
  • FIG. 3 is a cross sectional view taken on a plane indicated by and viewed in the direction of the arrows 3-3 of FIG. 1;
  • FIGS. 4 and 5 are enlarged cross sectional views taken on planes indicated by and viewed in the direction of the arrows 44 and 55 of FIG 1;
  • FIG. 6 is a cross sectional view taken on a plane indicated by and viewed in the direction of the arrows 6-6 of FIG. 1;
  • FIG. 7 is a bottom view taken on a plane indicated by and viewed in the direction of the arrows 7-7 of FIG. 6, and looking up at the underside portion of the air horn portion of the carburetor;
  • FIG. 8 is a cross sectional view taken on a plane indicated by and viewed in the direction of the arrows 8-8 of FIG. 6 and looking down on the main or central body portion of the carburetor;
  • FIGS. 9 and 10 are cross sectional views taken on planes indicated and viewed in the direction of the arrows 99 and 10-10 of FIG. 8.
  • FIG. I which is essentially to scale, is a plan view of a variable area venturi carburetor of the downdraft type. It has a pair of rectangularly shaped induction passages 10, each having one end wall 12 which is pivotally movable and has the profile (FIG. 3) of one-half of a venturi 13. Each opposite fixed cooperating wall 14 is formed with the mating profile of a portion of a venturi.
  • the airflow capacity therefore, varies in proportion to the opening movements of walls 12 of the in duction passages.
  • movable walls 12 are pivotally mounted at 15 on a stationary pin.
  • the pin ac tually is fixed to a strut, not shown, that depends from a section of the upper body of the carburetor.
  • Pivotally attached to each of the wall bodies is a fuel metering rod 16 that cooperates with a main fuel metering jet 18.
  • the needles have a controlled taper to provide a richer air/fuel mixture at the lower and higher ends of the venturi opening range.
  • Each jet is located in an aperture inside wall 14 at approximately the throat or most constricted section ofventuri 13.
  • a fuel float bowl or reservoir 20 has a pair of identical passages 22 conducting fuel to the main metering jets I8.
  • the carburetor throttle body portion 23 Downstream of the venturis, the carburetor throttle body portion 23 rotatably mounts a shaft 24 on which are fixed a pair (only one shown) of conventional throttle plates 25 that control the flow of air and fuel through induction passages 10.
  • venturis l3 and the movement of walls 12 is controlled in this case by a spring returned, control vacuum actuated, diaphragm type servo 26.
  • the servo consists of a hollow two-piece casting divided into two chambers 28 and 30 by an annular flexible diaphragm 32. The diaphragm is sealingly mounted along its edge in the casting.
  • Chamber 28 is an air chamber, connected to ambient or atmospheric pressure through a passage 34 (indicated also in FIGS. I, 6 and 8).
  • Chamber 30 is a vacuum chamber connected to induction passages 10 at a point below the throat but still in the venturi 13. This subjects chamber 30 to changes in a control vacuum that varies with airflow but at a rate that is slightly different than true venturi vacuum. The exact location of the tap of course is a matter of choice.
  • Chamber 30 also is connected to be actuated by ported intake manifold vacuum, for cold weather operation, as will be described in more detail later.
  • servo 26 has fixed to one side of diaphragm 32, by a retainer 35, a plunger or actuator 36.
  • the plunger is pivotally connected to a shaft 37 interconnecting cast portions of the movable walls 12.
  • Fixed to the other side of diaphragm 32 is a retainer 38 against which is seated a spring 39.
  • the other end of the spring bears against a seat 40 axially adjustable to vary the spring preload.
  • FIG. 3 indicates schematically in dotted lines a passage p between chamber 30 and induction passages 10.
  • servo chamber 30 is connected by a restricted line 41 (FIG. 8) to an intersecting passage 42 (FIGS. 810).
  • Passage 42 intersects with a vertically downwardly extending passage 44 (FIG. 10) containing a flow restrictor or orifice 46 and terminating in a chamber 48.
  • Chamber 48 is connected by a port 50 to induction passage I0 at a point below the edge of throttle valve 25 when it is in its closed position shown. In the position shown, therefore, as the throttle valve is rotated to an open position, port 50 is progressively subjected to the increased pres sure above the throttle valve to bleed the vacuum in passage 42.
  • Passage 42 also intersects with a right angled passage 52 (FIGS. 8, 9 and 5) that connects to a passage 54 (FIG. 5).
  • the latter passes vertically through the main body portion of the carburetor into a horizontal passage 56 located in the carburetor air horn section.
  • Passage 56 in turn is connected by a pair of passages 58 and 60 to the well 62 (FIG. 8) in which is arcuately movable one of the mounting members 70 (FIG. 3) for movable wall 12.
  • the well 62 in FIG. 8 and the adjacent induction passage 10 are interconnected by a depressed portion of the main body between the two so that the opening 63 shown in FIG. 5 senses the control or venturi-like vacuum connected by the passages named to servo chamber 30.
  • the opening 63 to the control vacuum in this case is adapted to be alternately restricted or progressively opened by a needle type valve 72.
  • the valve is movable into and out of the seat 63 in response to a temperature sensitive element, in a manner that will be described more clearly later. Suffice it to say at this point, that during normal engine operating temperatures, the needle valve 72 is completely withdrawn from opening 63 thereby permitting venturi-like vacuum to be sensed through passages 60, 58, 56, 54, 52, 42 and 40 to chamber 30 of the servo, the ported manifold vacuum simultaneously being sensed through port 50, chamber 48, line 42 to line 41 and servo chamber 30.
  • venturi-like vacuum passages 60, 58, 56, 54 and 52 are considerably larger than that of the ported manifold vacuum passage 44, coupled with the orifice 46, so that when the needle valve 72 is in the up position, the manifold vacuum is bled to the level of the venturi-like or control vacuum and, therefore, has essentially no effect on the movement of servo 26.
  • the manifold vacuum is used during cold weather operations to modulate the venturi-like or control vacuum to schedule the opening of the venturi 13 to regulate the richness of the fule/air mixture.
  • the venturi vacuum flow will be essentially blocked and manifold vacuum will be the prime force acting on servo chamber 30. This will cause the movable venturi walls 12 to be moved to a larger area venturi pulling the fuel metering rods l6 out further.
  • throttle valves 25 controls total airflow through both passages 10 to increase as the throttle valves are moved from their closed position.
  • An increase in airflow provides essentially a proportional increase in the control vacuum in chamber 30 from port 63 until the diaphragm 32 is moved towards the cup 40.
  • This moves both wall 12 to open induction passages 10 and increase the area of venturis 13 while simultaneously retracting the fuel metering rods 16 to increase fuel flow.
  • the total airflow and fuel flow vary with changes in throttle valve setting up to a maximum.
  • FIGS. 5, 6 and 8 show portions of both the cold running enrichment system as well as the cold start cranking fuel system.
  • the body portion of the carburetor is cast with a fuel bowl 20 containing fuel delivered thereto past a conventional inlet needle valve from a supply line 82.
  • the needle valve 80 is moved vertically in a bore 84 by the tab 86 secured to a float member 88 pivotally mounted at 90 on a depending portion of the air horn section of the carburetor.
  • the inlet valve 80 operates in a known manner. Movement of float 88 downwardly as a result of lowering of the liquid fuel level causes the needle 80 to drop. This permits fuel under pressure to enter the reservoir from line 82 to fill it again to the desired level. Raising of the float raises the inlet valve against the conical seat shown to shut off the supply when the desired level has been reached.
  • the lower portion of fuel bowl 20 contains a needle like cranking fuel supply valve (FIG. 5).
  • the latter has a conical valve portion 102 that cooperates with the upper edges 104 of a fuel well 106.
  • Valve 100 is connected to a temperature responsive device to be moved into and out of the wall with changes in temperature, in a manner to be described, to control the rate of flow of fuel from reservoir 20 into fuel well 106.
  • Well 106 is connected to an intersecting passage I12 (FIG. 8) that connects with a cross passage 114 to flow fuel into another passage 116 past a solenoid controlled valve unit 118.
  • unit 118 consists essentially of a valve 120 formed on the end of the armature of a solenoid 122.
  • a spring not shown normally biases valve 120 to close communication between passages 114 and 116.
  • the solenoid normally would be powered from the starter relay of the motor vehicle ignition system so that the solenoid is rendered operative only during engine starting conditions. That is, when the ignition key is turned to the start position, the solenoid l 18 would be energized and cause valve 120 to be retracted rightwardly to open communication between passages 114 and 116. A flow of starting fuel would then be permitted from fuel bowl 20 into passage I16.
  • the solenoid unit could include a manifold vacuum switch so the solenoid is not energized above a vacuum level of say 2 inches Hg, for example. It also could contain a thermal switch to prevent operation above 120F., for example, when extra cracking fuel usually is not needed.
  • the quantity of cranking fuel to be added to the in' duction passages, or, on the other hand, the position of cranking valve 100 is controlled by the connection of valve 100 to the lower end of a needle valve 140 (FIG. 5).
  • the needle valve forms a portion of the engine running fuel enrichment system. More specifically, needle valve 140 is tapered at its lower end as shown at 142, for a purpose to be described, and has a universal con' nection 144 to the plastic conical valve 100. The latter defines a variable flow area 145 between the valve and wall of well 106 that varies in size as a function of the vertical movement of valve 100. Therefore, vertical movement of valve 100 modulates the rate of flow of fuel from reservoir 20 into well 106 when solenoid valve 120 is opened.
  • the needle valve 140 moves upwardly and downwardly with changes in temperature, as will now be described.
  • the needle valve 140 in this case, is vertically movable in a well 146 in the upper body portion. It is axially aligned by a seal 148 and a valve seat 150 with which it cooperates to meter fuel.
  • the seal and seat define a chamber 152 which is connected by an angled passage 154 to the end 156 of a wormlike passage 158 best seen in FIG. 7.
  • the opposite end 160 of passage 158 connects with a vertical passage 162 (FIG. 6) that intersects an angled passage 164 leading to the plenum 126.
  • plenum 126 also receives fuel from the cranking fuel passage 124. Together then, the fuel passes into each induction passage through the side passages 128. It will be seen then that, depending upon the vertical position of needle valve 140, a quantity of fuel will flow past the tapered portion 142 of the needle valve into the various passages into induction passages 10 to supply additional fuel during cold running operation of the engine.
  • the vertical movement of needle valve 140 is controlled by a temperature sensitive element that moves the needle valve 140 upwardly to increase fuel flow as the temperature decreases below the normal operating level, and moves the needle valve 140 to a downward position to shut off the fuel enrichment when the temperature reaches the normal operating level.
  • the downward movement of needle valve 140 as the temperature increases will move the cranking fuel valve 100 downwardly in proportion to the temperature increase. Threfore, when the normal operating level is reached, cranking valve 100 will provide a maximum restriction to flow through the area 145, and very little additional fuel will then be added during starting of the engine.
  • the upper end of needle valve 140 is pivotally connected to the end of a lever 166.
  • the lever is pivotally mounted on a pin 168 projecting through an aperture in a boss 170 projecting from the carburetor upper body.
  • the opposite end of lever 166 is pivotally connected to an adjustable nut 172 on the upper end of a depending link 174.
  • the link 174 is adapted to be connected to a thermostatically responsive movable element to be described. Adjusting the upper end 172 of course will vary the operating characteristics of the system. Downward movement of link 174 is limited by abutment of the nut 172 against a stop washer 176.
  • a connector 178 pivotally engaging the threaded upper end 180 of needle valve 72.
  • the upper end 180 contains a yoke member 182 adjustably threaded to the end of needle valve 72 as shown to determine the upward and downward limits of movement of the needle valve.
  • FIGS. 1, 2 and 4 show the same more clearly.
  • the lower end of link 174 is pivotally connected to one end of a lever 216 that is fixed on a shaft 218.
  • the other end of lever 216 adjustably supports a screw 220 that bears against the end 222 of an essentially conventional fast idle cam 224.
  • the cam is rotatably mounted on shaft 218 and has a weighted lower end 223.
  • the end has a peripheral edge portion formed with a series of circumferentially contiguous steps 224, 226 and 228 and a high cam step 230. Each step progressively in the order named is of greater radial extent than the previous.
  • a lever or throttle stop 232 formed at its outer end with a curved engaging portion 234.
  • Lever 232 is rotatably mounted on throttle shaft 24. It has a depending tang portion 236 engaged by the end of an adjustably mounted screw 238 carried by a linkage 240 fixed to the throttle shaft 24.
  • a throttle return coil spring 242 has one end 244 anchored under a pin 246 extending from a fixed portion of the carburetor throttle flange. The opposite end of the spring bears against an angled tang 250 of linkage 240 thereby biasing the linkage and screw 238 in a clockwise direction against the tab end 236 oflever 232.
  • the lever 232 thus is constantly biased in a clockwise direction towards the edge surface of fast idle cam 224.
  • the cam steps therefore constitute abutment means or stops in the path of movement of lever 232 to determine the idle speed position of throttle plates 25.
  • the servo housing is hollow and divided into two chambers 270 and 272 by an edge mounted annular flexible diaphragm 274.
  • Chamber 270 is an air chamber communicating to the atmosphere through an opening 276.
  • Chamber 272 is a vacuum chamber communicating by a passage not shown with the induction passages at a location below the throttle valves 25.
  • a plunger 278 is riveted at one end 280 to a hat shaped spring retainer 282, and projects through a stop 284 for connection to the opposite end 286 of bell crank lever 264.
  • a compression spring 288 normally biases the plunger 278 upwardly to move bell crank 264, link 262, lever 258 and finger portion 254 in a clockwise direction.
  • the fast idle cam is controlled in its rotation by a lever 292 fixed on shaft 218.
  • the lever is located within a hollow cup-shaped housing 294 that is cast integrally with the throttle body portion '23.
  • Lever 292 has an upturned slotted end 296 in which is located the outer end 297 of a thermostatically responsive bimetallic spring coil 298.
  • the inner end of the spring is fixed on a stub shaft 300 projecting from an insulated cover 302.
  • the cover is fastened by screws to the housing 294 with an insulating gasket 302 between.
  • the gasket has an arcuate slot 304 along which the end 296 moves with tem perature changes.
  • the gasket also has a hole 306 through which projects the end 308 of a tube connected by a pair of passages 309 and 310 to the induction passages 10 at a location (not shown) below the throttle valves.
  • the cover 302 has been removed in FIG. 2, and FIG. 4 shows the outline of the housing in phantom, for orientation purposes.
  • the housing has a hot air inlet tube 312 connected by a passage 314 to the interior of housing 294 on the far side of gasket 302.
  • the tube would emanate from a known type of exhaust manifold heated stove in which air flowing past the manifold is warmed.
  • the throttle plate idle speed setting will be determined by which step is engaged by lever 232, during running operations of the engine.
  • the finger portion 254 will be inserted between the end 234 of lever 232 and whatever step or rotative cam position the fast idle cam 224 has attained so that the throttle plates are opened more for starting purposes than during normal cold running conditions.
  • lever 232 will move away from the fast idle cam and permit the servo spring 288 to move the finger portion 254 between the fast idle cam step 230 and lever 232.
  • the throttle plates now will be opened a maximum amount for the coldest start positions.
  • the induction passages at this time are at their smallest cross section because the servo spring 39 has moved walls 12 to this position. This, therefore, exposes the passages to a larger cranking vacuum signal so that the airflow across the fuel metering jets 18 is increased Simultaneously, the rotation of lever 216 moves link 174 downwardly to its extreme position until the stop 172 shown in FIG. 5 abuts the washer 176.
  • cranking vacuum signal is sufficient acting across the induction passage outlets 128 (FIG. 7) to draw fuel up cranking fuel circuit passage 124 into plenum 126.
  • fuel is drawn past the engine running fuel circuit needle valve 140 into the worm passage 158 (FIG. 7) to plenum chamber 126, where both circuits combine and the fuel inducted to provide the necessary starting richness.
  • release of the ignition switch to the engine running, posi tion deenergizes solenoid 118 to then again block the connection between the cranking supply line 114 and the line 116.
  • the valve 72 will also be down essentially blocking off port 63. Accordingly, the higher ported engine running manifold vacuum will act in servo chamber 30 and draw the walls 12 of the ven turis to open or enlarge the venturi area.
  • the opening of the venturis will decrease the air velocity across the fuel jet 18 to decrease the fuel metering signal while at the same time enlarging the fuel jet orifices.
  • the area of discharges 128 being constant, lowering the air velocity decreases the fuel metering signal to decrease fuel output through these passages.
  • the manifold vacuum is considerably higher than the cranking vacuum. This causes excess vaporization and would normally lead to a richer than desired mixture.
  • the ported manifold vacuum control in this case compensates for this by leaning the overall mixture to the desired level by opening the venturis.
  • the bimetallic coiled spring 298 will rotate the lever 216 in a counterclockwise direction away from the fast idle cam.
  • the cam then can move in the same direction by gravity when the throttle plates are opened beyond the fast idle position so that the end of lever 234 gradually moves progressively clockwise to permit the progressive closure of the throttle plates to less open idle speed positions.
  • the counterclockwise rotation of lever 216 effects an upward movement of link 174 to progressively move the needle valve 140 downwardly and thereby progressively close off the additional fuel flow past the valve. This movement also causes an upward movement of needle valve 72 so that the venturi-like vacuum decays whatever ported manifold vacuum signal is acting in servo chamber 30.
  • the lowering vacuum signal in pressure chamber 30 will permit the venturi walls 12 to move to contract the venturi area and move the metering rods 16 into the jet 18.
  • the throttle plates will be returned to a normal closed idle speed position, the needle valve 72 will be drawn essentially completely out of port 63 so that movement of the venturi walls will be controlled solely by control or venturi-like vacuum changes, and the supplemental fuel needle valve 140 will be moved downwardly to shut off or essentially close off the supply of additional fuel to the system.
  • the cranking valve will be at a minimum rate of flow position.
  • the closing venturi increases the air velocity past the fuel jet 18.
  • the fuel jet, threfore will have a smaller flow area. The total fuel flow will be less because the throttle plates are now closed more completely and because no fuel is now being inducted from passages 128, but only that through the main jets 18.
  • An engine cranking fuel supply system comprising, a carburetor having an induction passage connected to fresh air at one end and adapted to be connected to the engine intake manifold at the other end, a fuel port opening into the passage, and dual fuel supply means connected to the port for the induction of varying amounts of cranking fuel to the port as a function of changes in temperature from a predetermined level, the dual fuel supply means including first and second fuel passages each connected at one end to the fuel port and at its other end to a source of fuel, the first passage containing a valve variably movable between flow and no flow positions, the second passage containing an on-off valve movable to block and unblock the second passage, the second passage also containing flow control means variably movable in the second passage for modulating the rate of flow of fuel through the second passage, means biasing the valves towards noflow positions blocking the first and second fuel passages, means responsive to an engine cranking operation to move the on-off valve to an on-flow position permitting the induction of cranking fuel through the port from the
  • a cranking fuel system as in claim 2, the means biasing the valves including spring means biasing the lapered valve to an open position permitting the free supply of fuel from the reservoir to the second fuel passage.
  • thermoresponsive device operatively engages the tapered valve at times and moves the tapered valve to positions progressively decreasing the quantity of fuel admitted from the reservoir to the second fuel passage as the temperature increases towards the predetermined level.
  • An engine cranking fuel supply system comprising, a carburetor having an induction passage connected to fresh air at one end and adapted to be connected to the engine intake manifold at the other end, a fuel port opening into the passage, and dual fuel supply means connected to the port for the induction of varying amounts of cranking fuel to the port as a function of changes in temperature from predetermined level, the dual fuel supply means including first and second fuel passages each containing a temperature responsive flow control means variably movable to decrease the cranking fuel flow as temperature increases towards a predetermined level, a flow-noflow valve in the second passage movable to a flow position in response to an engine cranking operation to permit flow through the second passage and movable to a non-flow position in response to the engine attaining a running condition whereby fuel flow for cold engine operation is supplied in varying amounts to the fuel port from both passages below the predetermined temperature level during engine cranking, and from only the first passage after the engine hs attained a running condition.

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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)
US430819A 1974-01-04 1974-01-04 Carburetor cranking fuel flow rate control Expired - Lifetime US3897765A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
US430819A US3897765A (en) 1974-01-04 1974-01-04 Carburetor cranking fuel flow rate control
CA216,274A CA1036441A (en) 1974-01-04 1974-12-16 Carburetor cranking fuel flow rate control
AU76457/74A AU479388B2 (en) 1974-01-04 1974-12-16 Carburetor cranking fuel flow rate control
GB5530474A GB1475008A (en) 1974-01-04 1974-12-20 Carburetor cranking fuel system
DE19742461277 DE2461277A1 (de) 1974-01-04 1974-12-23 Einrichtung an einem vergaser fuer kraftfahrzeuge zur erzielung eines reicheren luft-brennstoff-gemisches
JP49149078A JPS5834664B2 (ja) 1974-01-04 1974-12-27 始動燃料濃厚化装置付気化器

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US430819A US3897765A (en) 1974-01-04 1974-01-04 Carburetor cranking fuel flow rate control

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US3897765A true US3897765A (en) 1975-08-05

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US430819A Expired - Lifetime US3897765A (en) 1974-01-04 1974-01-04 Carburetor cranking fuel flow rate control

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US (1) US3897765A (ja)
JP (1) JPS5834664B2 (ja)
CA (1) CA1036441A (ja)
DE (1) DE2461277A1 (ja)
GB (1) GB1475008A (ja)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1980000470A1 (en) * 1978-08-19 1980-03-20 Ford Motor Co Down-draft carburetor
US4205641A (en) * 1978-01-13 1980-06-03 Yamaha Hatsudoki Kabushiki Kaisha Start control means for internal combustion engine
US4276238A (en) * 1978-10-19 1981-06-30 Nissan Motor Company, Limited Carburetor with automatic choking and acceleration device
US9464588B2 (en) 2013-08-15 2016-10-11 Kohler Co. Systems and methods for electronically controlling fuel-to-air ratio for an internal combustion engine
US10054081B2 (en) 2014-10-17 2018-08-21 Kohler Co. Automatic starting system

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5756648A (en) * 1980-09-19 1982-04-05 Hitachi Ltd Carburettor with switch valve for preventing fuel vapor generation
FR2610995B1 (fr) * 1987-02-13 1989-11-10 Campos Jean Louis Dispositif de carburation a venturi elastique variable et gestion electronique pour moteurs a explosions

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US2940436A (en) * 1956-03-26 1960-06-14 Holley Carburetor Co Fuel control for an internal combustion engine
US2905165A (en) * 1957-05-21 1959-09-22 Thompson Ramo Wooldridge Inc Fuel enrichment device
US3587553A (en) * 1969-07-24 1971-06-28 Bendix Corp Carburetor priming system

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Publication number Priority date Publication date Assignee Title
US4205641A (en) * 1978-01-13 1980-06-03 Yamaha Hatsudoki Kabushiki Kaisha Start control means for internal combustion engine
WO1980000470A1 (en) * 1978-08-19 1980-03-20 Ford Motor Co Down-draft carburetor
US4404151A (en) * 1978-08-19 1983-09-13 Ford Motor Company Down-draft carburetor
US4276238A (en) * 1978-10-19 1981-06-30 Nissan Motor Company, Limited Carburetor with automatic choking and acceleration device
US9464588B2 (en) 2013-08-15 2016-10-11 Kohler Co. Systems and methods for electronically controlling fuel-to-air ratio for an internal combustion engine
US10240543B2 (en) 2013-08-15 2019-03-26 Kohler Co. Integrated ignition and electronic auto-choke module for an internal combustion engine
US10794313B2 (en) 2013-08-15 2020-10-06 Kohler Co. Integrated ignition and electronic auto-choke module for an internal combustion engine
US10054081B2 (en) 2014-10-17 2018-08-21 Kohler Co. Automatic starting system

Also Published As

Publication number Publication date
AU7645774A (en) 1976-06-17
GB1475008A (en) 1977-06-01
JPS5834664B2 (ja) 1983-07-28
CA1036441A (en) 1978-08-15
DE2461277A1 (de) 1975-07-10
JPS5097738A (ja) 1975-08-04

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