EP0232464A2 - Carburetor for internal combustion engines - Google Patents
Carburetor for internal combustion engines Download PDFInfo
- Publication number
- EP0232464A2 EP0232464A2 EP86113807A EP86113807A EP0232464A2 EP 0232464 A2 EP0232464 A2 EP 0232464A2 EP 86113807 A EP86113807 A EP 86113807A EP 86113807 A EP86113807 A EP 86113807A EP 0232464 A2 EP0232464 A2 EP 0232464A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- throttle
- carburetor
- engine
- air register
- controlled
- 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.)
- Granted
Links
Images
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
- F02M7/10—Other installations, without moving parts, for influencing fuel/air ratio, e.g. electrical means
- F02M7/11—Altering float-chamber pressure
Definitions
- the present invention relates to a carburetor for internal combustion engines with controlled ignition, designed to equip vehicles, of the type wherein fuel feed can be finely and promptly regulated according to the vehicle running conditions and to the engine working conditions, so as to comply, on one hand, with the strictest anti-pollution rules and to satisfy, on the other hand, the most elaborate working requirements.
- the strength of the air/fuel mixture fed by a carburetor to an internal combustion engine depends on the difference between the pressure existing in correspondence of fuel discharge into the main duct of the carburetor and the pressure existing in the constant level float chamber, above level. According to the most commonly known technique, this last pressure corresponds to ambient pressure or to the pressure existing just downstream of the carburetor air filter, and it is substantially constant. Whereas, the pressure in the main duct obviously varies according to the engine running conditions. As a result, it will be possible to obtain a satisfactory value of the strength of the mixture fed to the engine only in some of these conditions.
- an improvement has already been attempted by varying, at least in certain conditions, the pressure existing at the top of the constant level float chamber.
- it is already known, for instance from the DOS 2900732.7, to produce a depression into the top of the constant level float chamber of a carburetor, through a proper conduit leading into said chamber.
- said depression is obtained by using separate suction means controlled by sensors detecting the combustion state of the engine mixture.
- the depression into the top of the constant level float chamber is derived, with possibility of regulation, from the depression produced by engine running into the air intake of the carburetor; this allows - as has been proved by tests - to improve the working of the carburetor according to the conditions of use of the engine and of the vehicle onto which it is mounted.
- the carburetor according to the present invention which is of the type comprising an air register throttle inside the air intake, just downstream of the filter element - is characterized in that the top of the constant level float chamber is connected to external atmosphere, both downstream of said air register throttle and in correspondence of the throttle rim, and in that the position of said air register throttle is determined by an electric motor, controlled by sensors of the combustion state in the engine.
- Said sensors mainly comprise a probe to check the oxygen, positioned in the exhaust manifold of the engine, as well as detectors of other engine and environmental parameters.
- the devices characterizing the carburetor according to the invention can be advantageously used to perform also the functions of a pickup pump and/or - if suitably integrated with temperature sensors - of an automatic starter.
- the air register throttle is mounted idle on a shaft, in respect of which it is caused to rotate thanks to a worm drive mechanism operated by said electric motor, with possibility however to act independently from said mechanism when opening.
- the carburetor comprises, in known manner, a main duct 1, with choke 1A, having at one end the air intake 2, protected by a filter element 3, and at the opposite end - of mixture outlet to feed the engine - the throttle 4 controlled by the accelerator, a constant level chamber 5 with float 6, and fuel tubes and jets 7.
- the carburetor also comprises, in the air intake 2, an air register throttle 8 just downstream of the filter element 3.
- the top of the constant level float chamber 5 is connected to external atmosphere - through the air intake 2 of the duct 1 - in two different points: firstly, through the gauged port 9 opening directly into the chamber of the main duct 1, upstream of the choke 1A and downstream of the throttle 8; and secondly, through the tube 10 opening at 11 into the air intake 2 of the duct 1, in correspondence of the rim of said throttle 8.
- the throttle 8 (see fig. 2) is mounted idle on a shaft 12, in respect of which it can be caused to rotate thanks to a worm mechanism 13 operated by an electric motor 14 controlled, at 15, by sensors of the engine combustion state, through an electronic pilot circuit.
- the mechanism 13 acts by pressing onto the throttle 8, which is kept close to said pressure mechanism by a spring 16 acting so as to close said throttle. In this manner, the throttle 8 can open even independently from the pressure of the mechanism 13 and of the motor 14, when the carburetor working conditions so require.
- the sensors of the engine combustion state can consist of various devices detecting the environmental and operating features; in particular, a probe will definitely be used to check the presence of oxygen in the exhaust manifold of the engine.
- the use of temperature sensors will also be required when wishing to adopt the described arrangement in order to facilitate engine startup.
- the air-fuel ratio in the mixture fed to the engine is regulated by varying both the pressure of the air intaken by the carburetor and the pressure of the constant level float chamber. Since the mere metering through the air throttle would create difficulties of regulation when working with low air capacities (for instance, when idling and during the first running steps: in such cases, the throttle would be quite closed and any small movements would lead to excessive variations in the carburation), the invention has provided for two paths apt to connect the constant level float chamber to external atmosphere: the first (9) downstream of the air register throttle, subjected to the same pressure of the air let into the carburetor, and the second (10, 11) ending in correspondence of the throttle rim. During the closing movement of the throttle 8, the opening 11 is initially downstream of the throttle rim. In this way, the pressure on the opening 11 varies from a minimum value, produced by the pressure loss on the throttle, to a maximum value, when the throttle is completely closed
- the pressure in the fuel chamber which is the sum of the pressures on the two openings 9 and 11, can thus be regulated to a sufficiently wide extent as to allow a proper regulation of the air-fuel ratio in the mixture, in any running condition.
- the same circuit besides the functions of regulating the steady state of the engine, can also operate in the engine warming up steps and, when accelerating, to suitably enrich the mixture, so as to perform also the functions of starter and of pickup pump.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Control Of The Air-Fuel Ratio Of Carburetors (AREA)
Abstract
Description
- The present invention relates to a carburetor for internal combustion engines with controlled ignition, designed to equip vehicles, of the type wherein fuel feed can be finely and promptly regulated according to the vehicle running conditions and to the engine working conditions, so as to comply, on one hand, with the strictest anti-pollution rules and to satisfy, on the other hand, the most elaborate working requirements.
- As known, the strength of the air/fuel mixture fed by a carburetor to an internal combustion engine depends on the difference between the pressure existing in correspondence of fuel discharge into the main duct of the carburetor and the pressure existing in the constant level float chamber, above level. According to the most commonly known technique, this last pressure corresponds to ambient pressure or to the pressure existing just downstream of the carburetor air filter, and it is substantially constant. Whereas, the pressure in the main duct obviously varies according to the engine running conditions. As a result, it will be possible to obtain a satisfactory value of the strength of the mixture fed to the engine only in some of these conditions.
- According to the more advanced known technique, an improvement has already been attempted by varying, at least in certain conditions, the pressure existing at the top of the constant level float chamber. In particular, it is already known, for instance from the DOS 2900732.7, to produce a depression into the top of the constant level float chamber of a carburetor, through a proper conduit leading into said chamber. In the solution proposed in this patent, said depression is obtained by using separate suction means controlled by sensors detecting the combustion state of the engine mixture.
- Although this solution allows to obtain satisfactory results, both against pollution and for a proper engine performance, the increasing requirements in these respects have led designers to seek even better solutions.
- In the carburetor according to the present invention, the depression into the top of the constant level float chamber is derived, with possibility of regulation, from the depression produced by engine running into the air intake of the carburetor; this allows - as has been proved by tests - to improve the working of the carburetor according to the conditions of use of the engine and of the vehicle onto which it is mounted.
- In substance, the carburetor according to the present invention - which is of the type comprising an air register throttle inside the air intake, just downstream of the filter element - is characterized in that the top of the constant level float chamber is connected to external atmosphere, both downstream of said air register throttle and in correspondence of the throttle rim, and in that the position of said air register throttle is determined by an electric motor, controlled by sensors of the combustion state in the engine. Said sensors mainly comprise a probe to check the oxygen, positioned in the exhaust manifold of the engine, as well as detectors of other engine and environmental parameters.
- It should be noted that the devices characterizing the carburetor according to the invention can be advantageously used to perform also the functions of a pickup pump and/or - if suitably integrated with temperature sensors - of an automatic starter.
- Moreover, according to the invention, the air register throttle is mounted idle on a shaft, in respect of which it is caused to rotate thanks to a worm drive mechanism operated by said electric motor, with possibility however to act independently from said mechanism when opening.
- The invention is now illustrated in further detail, by mere way of example, with reference to a preferred embodiment thereof, shown on the accompanying drawing, in which:
- Fig. 1 is a conventional representation of the carburetor according to the invention; and
- Fig. 2 illustrates in detail the control of the air register throttle of the carburetor of figure 1.
- The carburetor according to the invention comprises, in known manner, a
main duct 1, withchoke 1A, having at one end theair intake 2, protected by afilter element 3, and at the opposite end - of mixture outlet to feed the engine - the throttle 4 controlled by the accelerator, aconstant level chamber 5 withfloat 6, and fuel tubes and jets 7. The carburetor also comprises, in theair intake 2, anair register throttle 8 just downstream of thefilter element 3. - According to the invention, the top of the constant
level float chamber 5 is connected to external atmosphere - through theair intake 2 of the duct 1 - in two different points: firstly, through the gaugedport 9 opening directly into the chamber of themain duct 1, upstream of thechoke 1A and downstream of thethrottle 8; and secondly, through thetube 10 opening at 11 into theair intake 2 of theduct 1, in correspondence of the rim of saidthrottle 8. - The throttle 8 (see fig. 2) is mounted idle on a
shaft 12, in respect of which it can be caused to rotate thanks to aworm mechanism 13 operated by anelectric motor 14 controlled, at 15, by sensors of the engine combustion state, through an electronic pilot circuit. Themechanism 13 acts by pressing onto thethrottle 8, which is kept close to said pressure mechanism by aspring 16 acting so as to close said throttle. In this manner, thethrottle 8 can open even independently from the pressure of themechanism 13 and of themotor 14, when the carburetor working conditions so require. - The sensors of the engine combustion state can consist of various devices detecting the environmental and operating features; in particular, a probe will definitely be used to check the presence of oxygen in the exhaust manifold of the engine. The use of temperature sensors will also be required when wishing to adopt the described arrangement in order to facilitate engine startup.
- As can be easily understood, in the heretofore described and illustrated carburetor, the air-fuel ratio in the mixture fed to the engine is regulated by varying both the pressure of the air intaken by the carburetor and the pressure of the constant level float chamber. Since the mere metering through the air throttle would create difficulties of regulation when working with low air capacities (for instance, when idling and during the first running steps: in such cases, the throttle would be quite closed and any small movements would lead to excessive variations in the carburation), the invention has provided for two paths apt to connect the constant level float chamber to external atmosphere: the first (9) downstream of the air register throttle, subjected to the same pressure of the air let into the carburetor, and the second (10, 11) ending in correspondence of the throttle rim. During the closing movement of the
throttle 8, theopening 11 is initially downstream of the throttle rim. In this way, the pressure on theopening 11 varies from a minimum value, produced by the pressure loss on the throttle, to a maximum value, when the throttle is completely closed. - The pressure in the fuel chamber, which is the sum of the pressures on the two
openings - For what concerns the control of the
throttle 8, it is evident that the electronic circuit - receiving the signals from the probe checking the oxygen in the exhaust manifold and from the other sensors detecting the environmental and engine parameters - will pilot themotor 14 for thethrottle 8, so as to cause the closing of said throttle when the signals indicate that the mixture is weak, and to cause its opening in the opposite event. - The same circuit, besides the functions of regulating the steady state of the engine, can also operate in the engine warming up steps and, when accelerating, to suitably enrich the mixture, so as to perform also the functions of starter and of pickup pump.
- The previous description evidently illustrates the invention by mere way of example, as the present invention can be realized also according to other embodiments and/or by introducing variants and modifications in the same. It is also understood that, though described in its application to a single carburetor, the invention can also be used to feed internal combustion engines having more carburetors.
Claims (3)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IT22524/85A IT1185460B (en) | 1985-10-17 | 1985-10-17 | CARBURETOR FOR INTERNAL COMBUSTION ENGINES |
IT2252485 | 1985-10-17 |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0232464A2 true EP0232464A2 (en) | 1987-08-19 |
EP0232464A3 EP0232464A3 (en) | 1987-08-26 |
EP0232464B1 EP0232464B1 (en) | 1991-07-24 |
Family
ID=11197419
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP86113807A Expired - Lifetime EP0232464B1 (en) | 1985-10-17 | 1986-10-06 | Carburetor for internal combustion engines |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0232464B1 (en) |
DE (1) | DE3680509D1 (en) |
ES (1) | ES2023109B3 (en) |
IT (1) | IT1185460B (en) |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1783214A (en) * | 1927-05-05 | 1930-12-02 | Carter Carburetor Corp | Carburetor |
US2609188A (en) * | 1948-11-22 | 1952-09-02 | Edward C Brehob | Air bleed structure for automatically controlling air and fuel ratio in carburetors at varying engine speeds |
US2681214A (en) * | 1950-10-02 | 1954-06-15 | Carter Carburetor Corp | Charge forming device |
DE2900732A1 (en) * | 1978-01-12 | 1979-07-19 | Ind Nazionale Carburatori Dell | CARBURETTORS FOR COMBUSTION ENGINES WITH MEANS OF MIXTURE CONTROL |
DE3211377A1 (en) * | 1982-03-27 | 1983-09-29 | Audi Nsu Auto Union Ag, 7107 Neckarsulm | Control device for a carburettor for internal combustion engines |
-
1985
- 1985-10-17 IT IT22524/85A patent/IT1185460B/en active
-
1986
- 1986-10-06 ES ES86113807T patent/ES2023109B3/en not_active Expired - Lifetime
- 1986-10-06 EP EP86113807A patent/EP0232464B1/en not_active Expired - Lifetime
- 1986-10-06 DE DE8686113807T patent/DE3680509D1/en not_active Expired - Fee Related
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1783214A (en) * | 1927-05-05 | 1930-12-02 | Carter Carburetor Corp | Carburetor |
US2609188A (en) * | 1948-11-22 | 1952-09-02 | Edward C Brehob | Air bleed structure for automatically controlling air and fuel ratio in carburetors at varying engine speeds |
US2681214A (en) * | 1950-10-02 | 1954-06-15 | Carter Carburetor Corp | Charge forming device |
DE2900732A1 (en) * | 1978-01-12 | 1979-07-19 | Ind Nazionale Carburatori Dell | CARBURETTORS FOR COMBUSTION ENGINES WITH MEANS OF MIXTURE CONTROL |
DE3211377A1 (en) * | 1982-03-27 | 1983-09-29 | Audi Nsu Auto Union Ag, 7107 Neckarsulm | Control device for a carburettor for internal combustion engines |
Also Published As
Publication number | Publication date |
---|---|
IT1185460B (en) | 1987-11-12 |
EP0232464B1 (en) | 1991-07-24 |
DE3680509D1 (en) | 1991-08-29 |
IT8522524A0 (en) | 1985-10-17 |
EP0232464A3 (en) | 1987-08-26 |
ES2023109B3 (en) | 1992-01-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4377142A (en) | Air/fuel ratio control system having an evaporated fuel purging control arrangement | |
US4700683A (en) | Device for purging evaporated fuel captured by a charcoal canister | |
US3503594A (en) | Fuel system | |
US3780718A (en) | Carburetor for an internal combustion engine | |
US3747903A (en) | Fuel supply system | |
US3957026A (en) | Cold starting enrichment device | |
US4398514A (en) | System for controlling no load operation of internal combustion engine | |
US4388904A (en) | Air-fuel ratio control system | |
US4164914A (en) | Air-fuel ratio controlling apparatus for an internal combustion engine | |
JPS59131724A (en) | Variable volume surge tank | |
GB1476852A (en) | Electro-pneumatic device for regulating the supply of air to an internal combustion engine | |
US4291659A (en) | Air-fuel ratio control system for an internal combustion engine | |
CA1155015A (en) | Electronic controlled carburetor | |
US4182294A (en) | Apparatus for injecting fuel into a multi-cylinder internal combustion engine having a supercharging compressor | |
US6945231B2 (en) | Fuel gas mixer | |
US4334513A (en) | Electronic fuel injection system for internal combustion engine | |
US4388905A (en) | Air-fuel ratio control system | |
KR890001730B1 (en) | Warming-up system of a car engine | |
US4098079A (en) | Secondary air feed control device of an internal combustion engine | |
EP0232464B1 (en) | Carburetor for internal combustion engines | |
US3774582A (en) | Idling speed control system for an automotive gasoline powered internal combustion engine | |
US4088102A (en) | Auxiliary acceleration fuel feed device in an internal combustion engine | |
US4377150A (en) | Apparatus for assisting engine starting | |
US4558680A (en) | System for controlling the air-fuel ratio supplied to a supercharged engine | |
US4290402A (en) | Gas-operated internal combustion engine |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
PUAL | Search report despatched |
Free format text: ORIGINAL CODE: 0009013 |
|
AK | Designated contracting states |
Kind code of ref document: A2 Designated state(s): DE ES FR GB |
|
AK | Designated contracting states |
Kind code of ref document: A3 Designated state(s): DE ES FR GB |
|
17P | Request for examination filed |
Effective date: 19870921 |
|
17Q | First examination report despatched |
Effective date: 19890208 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): DE ES FR GB |
|
REF | Corresponds to: |
Ref document number: 3680509 Country of ref document: DE Date of ref document: 19910829 |
|
ET | Fr: translation filed | ||
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FG2A Ref document number: 2023109 Country of ref document: ES Kind code of ref document: B3 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed | ||
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 19940928 Year of fee payment: 9 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: ES Payment date: 19940929 Year of fee payment: 9 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 19940930 Year of fee payment: 9 Ref country code: DE Payment date: 19940930 Year of fee payment: 9 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Effective date: 19951006 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: ES Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION Effective date: 19951007 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 19951006 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Effective date: 19960628 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Effective date: 19960801 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FD2A Effective date: 19990601 |