GB2108204A - Carburetor with a sonic idling system for an IC engine - Google Patents

Carburetor with a sonic idling system for an IC engine Download PDF

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Publication number
GB2108204A
GB2108204A GB08230840A GB8230840A GB2108204A GB 2108204 A GB2108204 A GB 2108204A GB 08230840 A GB08230840 A GB 08230840A GB 8230840 A GB8230840 A GB 8230840A GB 2108204 A GB2108204 A GB 2108204A
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United Kingdom
Prior art keywords
fuel
slow
intake passage
air intake
air
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.)
Withdrawn
Application number
GB08230840A
Inventor
Mamoru Matsubara
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.)
Aisan Industry Co Ltd
Original Assignee
Aisan Industry Co Ltd
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Publication date
Application filed by Aisan Industry Co Ltd filed Critical Aisan Industry Co Ltd
Publication of GB2108204A publication Critical patent/GB2108204A/en
Withdrawn legal-status Critical Current

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Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M3/00Idling devices for carburettors
    • F02M3/08Other details of idling devices
    • F02M3/12Passageway systems
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M7/00Carburettors with means for influencing, e.g. enriching or keeping constant, fuel/air ratio of charge under varying conditions
    • F02M7/12Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves
    • F02M7/14Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves with means for controlling cross-sectional area of fuel spray nozzle
    • F02M7/16Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves with means for controlling cross-sectional area of fuel spray nozzle operated automatically, e.g. dependent on exhaust-gas analysis
    • F02M7/17Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves with means for controlling cross-sectional area of fuel spray nozzle operated automatically, e.g. dependent on exhaust-gas analysis by a pneumatically adjustable piston-like element, e.g. constant depression carburettors

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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)

Abstract

An idling air intake passage 21 and/or an idling fuel passage 25 is provided with a fixed or adjustable restriction 22, 28. At or adjacent an air-fuel mixture outlet 21b of the idling air passage 21 there is provided a converging-diverging nozzle 23 which permits a flow rate of the air-fuel mixture at the throat portion 24 thereof to be at sonic velocity irrespective of variations in intake manifold vacuum during low speed engine operation. With this arrangement, the air-fuel ratio may be maintained at a constant value and accordingly, idling operation may be stabilized and pollutant exhaust gas emission may be reduced. <IMAGE>

Description

SPECIFICATION Carburetor for an internal combustion engine This invention relates to a carburetor for an internal combustion engine having a slow fuel system, and more particularly to a carburetor which may supply an air-fuel mixture to an intake manifold with the air-fuel ratio maintained at a constant value irrespective of any variations in intake manifold vacuum during low speed engine operation.
It is well known to provide a carburetor with a slow fuel system including an air intake passage which bypasses a throttle valve and in which fuel is injected with high velocity air flow from an idle port in the port in the slow fuel system. For example, the idle port is provided with a restriction means such as a venturi whereby the air velocity at the throat portion thereof becomes substantially sonic and a fuel discharging port is opened into the restriction means, thereby permitting fuel to be sucked by the negative pressure created in the restriction means and to be atomized by the air flow. The atomized air-fuel mixture is injected into an air intake passage. According to such a known arrangement, a sufficient pressure differential at the fuel discharge port may be obtained and mass air flow rate may be maintained at constant value.However, pressure at the fuel discharging port varies with fluctuations in intake manifold vacuum and accordingly, fuel flow rate also varies, with the result that air-fuel ratio may not be maintained at a constant value. In another known carburetor having a slow fuel system air and fuel are mixed in a slow air intake passage and thereafter, the air-fuel mixture is injected from an idle port at sonic velocity. In general, the pressure ratio P1/P2 (P,: pressure at the downstream portion of an idle port, i.e.
intake manifold vacuum; P2: pressure at the upstream portion of an idle port, i.e., pressure in the slow air intake passage) should be approximately equal to or less than 0.5 in order to render a flow rate of air-fuel mixture at the idle port to reach sonic velocity. However, in such a known carburetor, when the engine load becomes heavy and the throttle valve opening is increased so that the intake manifold vacuum becomes more than a value of about - 360 mmHg, the pressure ratio P./P2 becomes more than 0.5 and the flow rate of air-fuel mixture is reduced to a value less than the sonic velocity. As a result, there are variations in the mass air/fuel mixture flow rate and the air-fuel ratio.In a variable venturi type carburetor which generally does not have a slow fuel system, part of fuel which is discharged from the main jet during low speed engine operation and which sticks to an end surface of a suction piston or fuel may not be stably discharged because of a surrounding compiicated air stream. For the above reasons, a constant air-fuel ratio and stable idle operation may not be established.
It has been desired to solve this problem by providing a slow fuel system in a carburetor which ensures a constant fuel supply at all times and a constant air-fuel ratio.
Accordingly, a primary object of the present invention is to provide a carburetor having a slow fuel system which supplies an air-fuel mixture to the intake manifold at sonic velocity irrespective of variations in intake manifold vacuum during low speed engine operation.
Another object of the present invention is to provide a carburetor having a slow fuel system which ensures a constant air-fuel ratio irrespective of variations in intake manifold vacuum during low speed engine operation.
A further object of the present invention is to provide a carburetor having a slow fuel system which may stabilize an idle operation and reduce pollutant exhaust gas and furthermore, improve fuel consumption.
According to the present invention, at least one for each of a slow air intake passage and a slow fuel passage is provided with restriction means. At an air-fuel mixture outlet of the slow air intake passage or adjacent to the outlet, there is provided a convergingdiverging nozzle which permits a flow rate of the air-fuel mixture at the throat portion thereof to be at sonic velocity irrespective of variations in intake manifold vacuum during low speed engine operation. With this arrangement, an air-fuel ratio may be maintained at a constant value irrespective of variations in intake manifold vacuum during low speed engine operation, whereby idle operation maybe stabilized and pollutant exhaust gas may be reduced.
In order that the invention may be more readily understood, reference will now be made to the accompanying drawings, in which: Figure 1 is a vertical sectional view of a variable venturi carburetor according to a first preferred embodiment of the present invention; Figure 2 shows the relationship between air-fuel ratio and intake manifold vacuum according to the present invention in comparison with prior art; Figure 3 is a vertical sectional view of a variable venturi carburetor according to a second preferred embodiment; Figures 4 and 5 are vertical sectional views of the essential parts of variable venturi carburetors according to third and fourth preferred embodiments, respectively; and Figure 6 is a vertical sectional view of a fixed venturi carburetor according to a fifth preferred embodiment.
Referring now to Fig. 1, there is shown a carburetor body 1 of a variable venturi type having a float chamber 2, a first air intake passage 3, a throttle valve 4 and a venturi portion 5. Reference numeral 6 designates a main fuel passage communicating with the float chamber 2 and the venturi portion 5.
The main fuel passage 6 is provided with a main fuel jet 9. The venturi portion 5 is defined upstream of the throttle valve 4 by the inside wall 10 of the first air intake passage 3 and by the right-hand (as illustrated) end portion 1 2 of a suction piston 11.
A suction chamber 1 3 is defined by a cylindrical portion 1 a of the carburetor body 1 and by the suction piston 11 which is slidably inserted into the cylindrical portion 1a. A compression spring 1 5 is inserted in the suction chamber 1 3 and serves normally to urge the suction piston 11 toward the inside wall 10 of the first air intake passage 3. A vacuum communication port 1 6 is provided at the right-hand end portion 1 2 of the suction piston 11 and is adapted to communicate with the suction chamber 1 3 and the venturi portion 5. An atmospheric pressure chamber 1 7 is defined by the sliding flange portion 11 a of the suction piston 11 and by the carburetor body 1.The chamber 1 7 is provided with an atmospheric pressure communication port 1 8 in the vicinity of the inlet of the air intake passage 3, whereby ambient air is induced through the port 1 8. A fuel metering needle 1 9 is fixed to the right-hand end portion 1 2 of the suction piston 11 at its central portion.
The free end of the metering needle 1 9 is laterally reciprocably inserted in the interior of the main fuel jet 9.
Reference numeral 21 designates a second air intake passage. An air inlet 21 a of the second air intake passage 21 opens into the first air intake passage 3 on the upstream side of the venturi portion 5 and an air/fuel outlet 21b opens into the first air intake passage 3 on the downstream side of the throttle valve 4. The second air intake passage 21 is provided with a fixed venturi 22 on the way thereof and is provided with a nozzle 23 adjacent to the air/fuel outlet 21 b. The nozzle 23 is designed in such a manner that an amount of air passing through its throat portion 24 becomes smaller than an amount of induced air during idle operation. A fuel discharging port 26 in communication with a slow fuel passage 25 opens into the most restricted portion of the fixed venturi 22.The slow passage 25 communicates with the float chamber 2 via a slow jet 27 provided on the way thereof and opens into the upstream portion of the second air intake passage 21 through an air restriction 28 diposed opposite the slow jet 27.
In operation, during middle and high speed engine operation, the suction piston 11 laterally reciprocates in response to an amount of air induced by engine vacuum and accordingly, fuel stored in the float chamber 2 is supplied through the main fuel passage 6 to the main fuel jet 9 and is metered by the metering needle 1 9 and the main fuel jet 9, and then is discharged into the venturi portion 5, wherein the amount of fuel to be dis charged is proportional to the amount of air passing through the venturi portion 5. During low speed engine operation, the throttle valve 4 is in its nearly closed position, so that air is dominantly induced through the air inlet 21a into the second air intake passage 21 and negative pressure is created at the most re stricted portion of the fixed venturi 22.Be cause of this negative pressure, the fuel stored in the float chamber 2 is sucked up through the slow fuel passage 25 to the slow jet 27. For a while, part of the induced air is metered by the air restriction 28 to enter the slow fuel passage 25. Thus, such metered air is mixed with the fuel metered by the slow jet 27 and the air-fuel mixture, which is under emulsified state, flows through the down stream portion cf the slow fuel passage 25 to be discharged from the fuel discharging port 26.Such discharged air-fuel mixture is intro duced to the nozzle 23 and flow velocity of the mixture is accelerated by the pressure differential existing between the upstream and the downstream portions of the nozzle 23, thereby injecting the accelerated air-fuel mix ture from the outlet 21 b into the downstream portion of the throttle valve 4 and then intro ducing such injected fuel to an intake mani fold (not shown).
It is generally known in the art that when the ratio of the pressure at the most restricted portion of the nozzle to the pressure at the entry thereof reaches the value of 0.528, the gas velocity reaches a constant sonic velocity at the most restricted portion and the mass gas flow rate at the nozzle becomes constant.
Accordingly when a converging nozzle is em -ployed, the ratio of the pressure at its most restricted portion or at its exit to the pressure at the entry needs to be increased. If such a converging nozzle is used for the nozzle 23 in the first preferred embodiment, sonic velocity may be achieved, provided that ratio of the exit pressure or the intake manifold vacuum to the entry pressure is equal to or less than the value of 0.528. As a result, the range of the intake manifold vacuum is considerably limsited. Consequently, in the first preferred em bodiment, the nozzle 23 is a convergingdiverging nozzle which converges from its entry to its throat portion and diverges from its throat portion to its exit. In this type of converging-diverging nozzle 23, PO/Pj (Pj: en try pressure; PO: exit pressure or intake mani -fold vacuum) ranges from 0 to 0.8 and PO/P.
(P,: pressure at the throat portion) is equal to or less than 0.528. Thus, the velocity at the throat portion 24 becomes sonic and the mass air flow rate at the nozzle 23 becomes constant. If Pi is atmospheric pressure, P0 ranges from - 760 mmHg to - 1 52 mmHg.
However, in the first preferred embodiment, as the air-fuel mixture flows through the nozzle 23, P0 practically ranges from - 760 mmHg to - 200 mmHg, which may be a sufficient value to cover the low speed area of operation. Accordingly, the mass air flow rate at the nozzle 23 is at all times constant irrespective of variations in the intake manifold vacuum, and as a result, the negative pressure downstream of the fixed venturi 22 becomes constant. Consequently, the fuel flow rate at the fixed venturi 22 is also constant irrespective of variations in the intake manifold vacuum.
Referring next to Fig. 2, the air-fuel ratio is all times constant irrespective of variations in intake manifold vacuum at an engine speed of 800 rpm as shown by the solid lines. On the other hand, in a conventional carburetor, the air-fuel ratio varies with intake manifold vacuum as shown by the dashed line.
As should be apparent from the above description, the carburetor of this embodiment ensures a constant air-fuel ratio and a stable fuel supply. As a result, idle operation may be stabilized and pollutant exhaust gas may be reduced, and furthermore fuel consumption may be improved.
In some embodiments which will be hereinafter described, the same reference numerals are used to designate the same parts or elements.
Referring next to Fig. 3, which illustrates a variable venturi carburetor of the second preferred embodiment, there is provided a variable restriction means at the air inlet of the second air intake passage 21. The variable restriction means comprises a seat 30 and a tapered needle 31 threaded through the carburetor body 1 and adapted to be reciprocably inserted into the seat 30. The needle 31 is biased by a compression spring 32 toward its head portion and thus, the degree of opening of the seat 30 may be adjusted by changing the extent of insertion of the needle 31. The slow fuel passage 25 opens into the second air intake passage 21 directly downstream of the seat 30. A slow jet 33 is provided at the fuel outlet of the float chamber 2 communicating with the slow fuel passage 25. A nozzle 23 is provided at the airfuel outlet of the second air intake passage 21.The nozzle 23 is a converging-diverging type nozzle similar to that employed in the first preferred embodiment and a part of the nozzle 23 projects into the first air intake passage 3 downstream of the throttle valve 4.
The air velocity at the throat portion 24 of the nozzle 23 is sonic under a manifold vacuum of - 760 mmHg to - 200 mmHg.
In operation, air is introduced through the annular clearance defined between the needle 31 and the seat 30 into the second air intake passage 21, thereby creating a negative pressure at the opening of the slow fuel passage 25. On the other hand, fuel stored in the float chamber 2 is metered by the slow jet 33 and is introduced to its opening where the fuel is discharged and mixed with the air supplied through the seat 30, wherein even if the negative pressure at the opening of the slow fuel passage 25 at the opening of the slow fuel passage 25 is about 5 percent of the manifold vacuum of - 500 mmHg, fuel metering of the slow system may be ensured. The velocity of the air-fuel mixture at the throat portion 24 of the nozzle 23 becomes sonic and the mass fuel flow rate is maintained at a constant level.Under these conditions, the air-fuel mixture is injected from the nozzle 23 into the first air intake passage 5 and is then introduced to the intake manifold (not shown), thereby accomplishing satisfactory effectiveness similar to that in the previous preferred embodiment.
When the extent of insertion of the needle 31 into the seat 30 is varied, the velocity of air flowing into the second air intake passage 21 is varied with the air flow maintained at constant level because of constant mass airfuel mixture flow rate at the nozzle 23. As a result, the negative pressure at the opening of the slow fuel passage 25 into the second air intake passage 21 and the fuel flow rate is varied. As is apparent from the foregoing description, control of fuel flow rate or the airfuel ratio may be ensured by adjusting the extent of insertion of the needle 31 into the seat 30, and the air-fuel ratio may be set to a required value.
Referring next to Fig. 4 illustrating a part of a carburetor of a third preferred embodiment, there is provided an air restriction means 35 at an air inlet of the second air intake passage 21 which means serves to generate a negative pressure downstream of the means 35 required for metering fuel flow rate in the flow fuel system. A nozzle 23 similar to that in the embodiment of Fig. 3 is provided at the airfuel mixture outlet of the second air intake passage 21. Th slow fuel passage 25 opens into the second air intake passage 21 on the way thereof, and is provided with a variable fuel restriction means comprising a seat 36 and a tapered needle 37 reciprocably inserted into the seat 36. As is similar to the previous preferred embodiment, the needle 37 is threaded into a hole in the carburetor body 1 and is biased outwardly of the body 1 by a compression spring 38.With this arrangement, the extent of insertion of the needle 37 into the seat 36 may be controlled and accordingly, the degree of opening of the variable fuel restriction means.
In operation, when the air flowing in the first air intake passage 3 is introduced through the air restriction means 35 into the second air intake passage 21, the fuel stored in the float chamber 2 is sucked up by way of the second air intake passage 25 upstream of the variable fuel restriction means and the fuel flow rate is controlled by the variable fuel restriction means. The fuel dicharged from the variable fuel restriction means is mixed with the air flowing in the second air intake passage 21 and it then supplied to the nozzle 23.
At the throat portion 24 of the nozzle 23, the velocity of air-fuel mixture becomes sonic under the condition of constant mass air-fuel mixture flow rate. Thus, the air-fuel mixture is injected into the first air intake passage 3 downstream of the throttle valve 4 and is then induced into an intake manifold (not shown).
As is similar to the embodiment of Fig. 3, the fuel flow rate may be controlled by adjusting the extent of insertion of the needle 37 into the seat 36 and therefore the air-fuel ratio may be set to a required value.
Referring now to Fig. 5, which illustrates a part of a variable.venturi carburetor of the third preferred embodiment, there is provided an air restriction means 40 at an air inlet of the second air intake passage 21 which means 40 serves to generate a negative pressure downstream thereof required.for metering fuel flow rate in the slow fuel system. A nozzle 23 similar to that of Fig. 4 is provided at an air-fuel mixture outlet of the second air intake passage 21. The slow fuel passage 25 opens into the second air intake passage 21 directly downstream of the air restrictions means 40. A slow jet 41 is provided at the fuel outlet of the float chamber 2 communicating with the slow fuel passage 25.There is provided, at the opening of the slow fuel passage 25, a variable restriction means which comprises a seat 42 and a tapered needle 43 threaded through the carburetor body 1 and which is adapted to be reciprocably inserted into the seat 42. The needle 43 is biased by a compression spring 44 toward its head portion and thus, the degree of opening of the seat 42 may be adjusted by changing the extent of insertion of the needle 43 into the seat 42.
In operation, air is introduced through the air restriction means 40 into the second air intake passage 21, thereby creating a negative pressure at the opening of the slow fuel passage 25. On the other hand, fuel stored in the float chamber 2 is metered by the slow jet 41 and is introduced to is opening where the fuel is discharged and mixed with the air supplied through the seat 42. As the velocity of the air-fuel mixture at the throat portion 24 of the nozzle 23 becomes sonic and the mass flow rate is constant, the velocity of air introduced through the air restriction means 40 becomes constant.However, when the introduced air is supplied to the variable air-fuel mixture restriction means, the velocity of the air-fuel mixture increases with the degree of opening of the seat 42 and thereafer gradually decreases to the extent that it corresponds to the cross-sectional area of the second air intake passsage 21. In this embodiment, the slow fuel passage 25 opens into the second air intake passage 21 directly upstream of the seat 42 and accordingly, the negative pres sure at the opening will be influenced by the variable air-fuel mixture restriction means, i.e., the negative pressure at the opening of the slow fuel passage 25 varies with the extent of insertion of the needle 43 into the seat 42 and thus the fuel flow rate is varied.Accord ingly, the air-fuel ratio may be controlled by changing the extent of insertion of the needle 43 to set it to a required value as is similar to the second and the third preferred embodi ments.
Referring next to Fig. 6 illustrating a carbu retor provided with a well-known fixed ven turi, according to the fifth preferred embodi ment, reference numeral 51 designates a car buretor body of a fixed venturi type having a float chamber 52, a first air intake passage 53, a throttle valve 54, a venturi portion 55 and a small venturi 56. Reference numeral 57 designates a main fuel passage communicat ing with the float chamber 52 and the small venturi 56. A main fuel jet 58 is provided near the fuel outlet of the float chamber 52.
Reference numeral 59 designates a second air intake passage which opens into the first air intake passage 53 upstream of the small venturi 56 and which also opens into the passage 53 downstream of the throttle valve 54. A variable air restriction means, which comprises a seat 60 and a tapered needle 61 threaded into a hole in the carburetor body 51 and is adapted to be reciprocably inserted into the seat 60, is provided on the way of the second air intake passage 59. The needle 61 is biased by a compression spring 62 toward its head portion and thus, the degree of opening of the seat 60 may be controlled by changing the extent of insertion of the needle 61 into the seat 60. A slow fuel passage 63 communicating with a main fuel passage 57 through a slow jet 64 is provided downstream of the variable air restriction means. A nozzle 65 is provided at the air-fuel mixture outlet of the second air intake pas sage 59. The nozzle 65 is a converging diverging type nozzle similar to that employed in the embodiment of Fig. 5 and a part of the nozzle 65 projects into the first air intake passage 53 downstream of the throttle valve 54. The air velocity at the throat portion 66 of the nozzle 65 is sonic under a manifold va cuum of - 760 mmHg to - 200 mmHg.
During low speed engine operation, air is induced through the second air intake passage 59 to the variable restriction means and a negative pressure is created downstream of the variable restriction means. Because of this negative pressure, the fuel stored in the float chamber 52 is sucked up through the slow 'fuel passage 63 after being metered by the slow jet 64 and is mixed with the air directly downstream of the needle 61. Such an airfuel mixture is supplied to the nozzle 65 where the velocity of the mixture becomes sonic and is injected into the first air intake passage 53 downstream of the throttle valve 54 As is similar to the embodiment of Fig. 3, when the extent of insertion of the needle 61 into the seat 60 is varied, the velocity of air flowing through the variable restriction means is varied under the condition of contant air flow rate. As a result, the negative pressure at the opening of the slow fuel passage 63 into the second air intake passage 59 is varied, and accordingly, fuel flow rate is also varied.
Consequently, control of fuel flow rate or airfuel ratio may be ensured by adjusting the extent of insertion of the needle 61 into the seat 60, and the air-fuel ratio may be set to the required value.
Having thus described the preferred embodiments of the invention is should be understood that numerous structural modifications and adaptations may be restored to without departing from the spirit of the invention.

Claims (11)

1. A carburetor for an internal combustion engine, having a main air intake passage, a throttle valve provided in said main air intake passage, a slow air intake passage bypassing said throttle valve, an air inlet provided at one end of said slow air intake passage and opening into said main air intake passage upstream of said throttle valve, an air-fuel mixture outlet provided at the other end of said slow air intake passage and opening into said main air intake passage downstream of said throttle valve, a float chamber, and a slow fuel passage communicating with said float chamber and said slow air intake passage, wherein restriction means is provided in at least one of said slow air intake passage and said slow fuel passage and a converging-diverging nozzle is provided at or adjacent said air-fuel mixture outlet of the slow air intake passage, said nozzle permitting a flow rate of air-fuel mixture at the throat portion of said converging-diverging nozzle to be at sonic valocity irrespective of variations in intake manifold vacuum.
2. The carburetor as defined in claim 1, wherein said restriction means provided in said slow air intake passage is fixed venturi and said slow fuel passage opens into a throat portion of said fixed venturi.
3. The carburetor as defined in claim 1, wherein said restriction means for the slow air intake passage is provided downstream of said air inlet and said slow fuel passage opens into said slow air intake passage on the downstream side of said restriction means for the slow air intake passage.
4. The carburetor as defined in claim 1, wherein said restriction means for the slow air intake passage is a variable restriction comprising a seat and a needle reciprocably inserted into said seat for adjusting the degree of opening of said seat.
5. The carburetor as defined in claim 1, wherein said restriction means for the slow fuel passge is a variable restriction comprising a seat and a needle reciprocably inserted into said seat for adjusting the degree of opening of said seat.
6. The carburetor as defined in claim 1, wherein said restriction means for the slow air intake passage comprises a fixed restriction provided at said inlet and a variable restriction provided downstream of said fixed restriction, said variable restriction comprising a seat and a needle reciprocably inserted into said seat for adjusting the degree of opening of said seat, said slow fuel passage opening into the portion defined between said fixed and said variable restriction means.
7. A carburetor, substantially as hereinbefore described with reference to Fig. 1 of the accompanying drawings.
8. A carburetor, substantially as hereinbefore described with reference to Fig. 3 of the accompanying drawings.
9. A carburetor, substantially as herinbefore described with reference to Fig. 4 of the accompanying drawings.
1 0. A carburetor, substantially as hereinbefore described with reference to Fig. 5 of the accompanying drawings.
11. A carburetor, substantially as hereinbefore described with reference to Fig. 6 of the accompanying drawings.
1 2. A carburetor, substantially as hereinbefore described with reference tr. Figs. 1 and 2 of the accompanying drawings.
1 3. A carburetor, substantially as hereinbefore described with reference to Figs. 2 and 3 or Figs. 2 and 4 or Figs. 2 and 5 or Figs. 2 and 6 of the accompaning drawings.
GB08230840A 1981-10-31 1982-10-28 Carburetor with a sonic idling system for an IC engine Withdrawn GB2108204A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16278781U JPS5867951U (en) 1981-10-31 1981-10-31 vaporizer

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GB2108204A true GB2108204A (en) 1983-05-11

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GB08230840A Withdrawn GB2108204A (en) 1981-10-31 1982-10-28 Carburetor with a sonic idling system for an IC engine

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JP (1) JPS5867951U (en)
DE (1) DE3238171A1 (en)
FR (1) FR2515737A1 (en)
GB (1) GB2108204A (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1224457B (en) * 1988-09-30 1990-10-04 Marco Morini GROUP FOR THE SUPPLY OF A CARBURATION ENGINE IN SPECIAL OPERATING CONDITIONS

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1881433A (en) * 1929-08-12 1932-10-11 Marvel Carbureter Co Carburetor
GB1151802A (en) * 1967-01-12 1969-05-14 British Motor Corp Ltd Carburetters for Internal Combustion Engines.
FR1547734A (en) * 1967-10-19 1968-11-29 Sibe Improvements to carburettors for internal combustion engines
FR1543621A (en) * 1967-10-27 1968-10-25 Carburetor
US3711069A (en) * 1969-08-15 1973-01-16 Ford Motor Co High velocity carburetor idle system
DE2325045C2 (en) * 1972-05-17 1985-07-25 Alfa Romeo S.p.A., Mailand/Milano Carburetors for internal combustion engines
GB1451100A (en) * 1973-11-16 1976-09-29 Ford Motor Co Carburettor idle system
FR2268950B1 (en) * 1974-04-23 1979-03-09 Sibe
JPS53115416A (en) * 1977-03-18 1978-10-07 Nissan Motor Co Ltd Variable venturi carburetor
DE2817026C2 (en) * 1978-04-19 1983-07-07 Central'nyj nau&ccaron;no-issledovatel'skij avtomobil'nyj i avtomotornyj institut (NAMI), Moskva Idle fuel system in a carburetor for internal combustion engines
DE2855683C2 (en) * 1978-12-22 1982-12-16 Pierburg Gmbh & Co Kg, 4040 Neuss Carburetors for internal combustion engines
JPS56126654A (en) * 1980-03-11 1981-10-03 Nissan Motor Co Ltd Electronic controlled carburetor

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JPS5867951U (en) 1983-05-09
FR2515737A1 (en) 1983-05-06
DE3238171A1 (en) 1983-05-05

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