EP0232464B1 - Carburetor for internal combustion engines - Google Patents

Carburetor for internal combustion engines Download PDF

Info

Publication number: EP0232464B1
Authority: EP; European Patent Office
Prior art keywords: throttle valve; carburetor; register; engine; register throttle
Prior art date: 1985-10-17
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.): Expired - Lifetime

Application number

EP86113807A

Other languages

German (de)

English (en)

French (fr)

Other versions

EP0232464A2 (en

EP0232464A3 (en

Inventor

Pierluigi Dell'orto

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.)

Dell Orto SpA

Original Assignee

Dell Orto SpA

Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)

1985-10-17

Filing date

1986-10-06

Publication date

1991-07-24

1986-10-06 Application filed by Dell Orto SpA filed Critical Dell Orto SpA

1987-08-19 Publication of EP0232464A2 publication Critical patent/EP0232464A2/en

1987-08-26 Publication of EP0232464A3 publication Critical patent/EP0232464A3/en

1991-07-24 Application granted granted Critical

1991-07-24 Publication of EP0232464B1 publication Critical patent/EP0232464B1/en

2006-10-06 Anticipated expiration legal-status Critical

Status Expired - Lifetime legal-status Critical Current

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.
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 present invetion concerns a carburetor in which a fine and continuous regulation of the feed mixture strength is obtained producing a controlled depression in the top of a constant level float chamber
the carburetor comprising a register throttle valve in an air intake duct and downstream thereof a main duct with a venturi followed by an accelerator throttle valve, the top of said constant level float chamber being connected with external atmosphere by an opening which opens into the air intake duct upstream of the register throttle valve when the register throttle valve is in its closed position, and being connected by a gauged port with the main duct, downstream of the register throttle valve and upstream of the venturi.
This carburetor is characterized in that the opening connecting the top of the constant level float chamber with the air intake duct opens through the wall of the air intake duct and is positioned with regard to the register throttle valve so that it is upstream of the rim of the register throttle valve when the register throttle valve is in its closed position and downstream of the rim when it is in its fully open position, in that said air register throttle valve is asymmetric and has its minor sector corresponding to said opening, and in that the position of said air register throttle valve is determined by an electric motor controlled by sensors detecting the combustion state of the engine.
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)

EP86113807A 1985-10-17 1986-10-06 Carburetor for internal combustion engines Expired - Lifetime EP0232464B1 (en)

Applications Claiming Priority (2)

Application Number	Priority Date	Filing Date	Title
IT22524/85A IT1185460B (it)	1985-10-17	1985-10-17	Carburatore per motori a combustione interna
IT2252485		1985-10-17

Publications (3)

Publication Number	Publication Date
EP0232464A2 EP0232464A2 (en)	1987-08-19
EP0232464A3 EP0232464A3 (en)	1987-08-26
EP0232464B1 true 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 (it)
DE (1)	DE3680509D1 (it)
ES (1)	ES2023109B3 (it)
IT (1)	IT1185460B (it)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
DE2900732A1 (de) *	1978-01-12	1979-07-19	Ind Nazionale Carburatori Dell	Vergaser fuer verbrennungsmotoren mit mitteln zur gemischregelung

Family Cites Families (4)

* Cited by examiner, † Cited by third party
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
DE3211377A1 (de) *	1982-03-27	1983-09-29	Audi Nsu Auto Union Ag, 7107 Neckarsulm	Steuervorrichtung fuer einen vergaser fuer brennkraftmaschinen

1985
- 1985-10-17 IT IT22524/85A patent/IT1185460B/it active
1986
- 1986-10-06 ES ES86113807T patent/ES2023109B3/es not_active Expired - Lifetime
- 1986-10-06 EP EP86113807A patent/EP0232464B1/en not_active Expired - Lifetime
- 1986-10-06 DE DE8686113807T patent/DE3680509D1/de not_active Expired - Fee Related

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
DE2900732A1 (de) *	1978-01-12	1979-07-19	Ind Nazionale Carburatori Dell	Vergaser fuer verbrennungsmotoren mit mitteln zur gemischregelung

Also Published As

Publication number	Publication date
IT1185460B (it)	1987-11-12
DE3680509D1 (de)	1991-08-29
IT8522524A0 (it)	1985-10-17
EP0232464A2 (en)	1987-08-19
EP0232464A3 (en)	1987-08-26
ES2023109B3 (es)	1992-01-01

Legal Events

Date	Code	Title	Description
1987-07-04	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
1987-07-09	PUAL	Search report despatched	Free format text: ORIGINAL CODE: 0009013
1987-08-19	AK	Designated contracting states	Kind code of ref document: A2 Designated state(s): DE ES FR GB
1987-08-26	AK	Designated contracting states	Kind code of ref document: A3 Designated state(s): DE ES FR GB
1987-11-19	17P	Request for examination filed	Effective date: 19870921
1989-03-22	17Q	First examination report despatched	Effective date: 19890208
1991-06-07	GRAA	(expected) grant	Free format text: ORIGINAL CODE: 0009210
1991-07-24	AK	Designated contracting states	Kind code of ref document: B1 Designated state(s): DE ES FR GB
1991-08-29	REF	Corresponds to:	Ref document number: 3680509 Country of ref document: DE Date of ref document: 19910829
1991-10-11	ET	Fr: translation filed
1992-01-01	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
1992-05-28	PLBE	No opposition filed within time limit	Free format text: ORIGINAL CODE: 0009261
1992-05-28	STAA	Information on the status of an ep patent application or granted ep patent	Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT
1992-07-15	26N	No opposition filed
1994-09-28	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
1994-09-29	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
1994-09-30	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
1995-10-06	PG25	Lapsed in a contracting state [announced via postgrant information from national office to epo]	Ref country code: GB Effective date: 19951006
1995-10-07	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
1996-06-05	GBPC	Gb: european patent ceased through non-payment of renewal fee	Effective date: 19951006
1996-06-28	PG25	Lapsed in a contracting state [announced via postgrant information from national office to epo]	Ref country code: FR Effective date: 19960628
1996-08-01	PG25	Lapsed in a contracting state [announced via postgrant information from national office to epo]	Ref country code: DE Effective date: 19960801
1996-09-06	REG	Reference to a national code	Ref country code: FR Ref legal event code: ST
1999-07-01	REG	Reference to a national code	Ref country code: ES Ref legal event code: FD2A Effective date: 19990601

Publication	Publication Date	Title
US4499887A (en)	1985-02-19	Dual fuel supply system
US3747903A (en)	1973-07-24	Fuel supply system
US3957026A (en)	1976-05-18	Cold starting enrichment device
US4007721A (en)	1977-02-15	Fuel metering apparatus for a carburetor
US4388904A (en)	1983-06-21	Air-fuel ratio control system
US4164914A (en)	1979-08-21	Air-fuel ratio controlling apparatus for an internal combustion engine
CA1155015A (en)	1983-10-11	Electronic controlled carburetor
US4291659A (en)	1981-09-29	Air-fuel ratio control system for an internal combustion engine
US4334513A (en)	1982-06-15	Electronic fuel injection system for internal combustion engine
US4098079A (en)	1978-07-04	Secondary air feed control device of an internal combustion engine
EP0232464B1 (en)	1991-07-24	Carburetor for internal combustion engines
US4183334A (en)	1980-01-15	Fuel saving control system for internal combustion engines
US3774582A (en)	1973-11-27	Idling speed control system for an automotive gasoline powered internal combustion engine
US4558680A (en)	1985-12-17	System for controlling the air-fuel ratio supplied to a supercharged engine
EP0058396B1 (en)	1986-05-28	Carburetor with starting system
US4377150A (en)	1983-03-22	Apparatus for assisting engine starting
US3943205A (en)	1976-03-09	Internal combustion engine
US4164208A (en)	1979-08-14	Exhaust gas recirculation means
US3034492A (en)	1962-05-15	Vacuum controlled gas saver
US3880963A (en)	1975-04-29	Method and apparatus for varying fuel flow to compensate for changes in operating temperature
GB2137692A (en)	1984-10-10	System for controlling the ignition timing of an engine
GB2028431A (en)	1980-03-05	Improvements in and relating to Carburettors
US4164207A (en)	1979-08-14	Exhaust gas recirculation means
US4556031A (en)	1985-12-03	System for controlling a carburetor of an internal combustion engine
US4128088A (en)	1978-12-05	Apparatus and system for controlling the air-fuel ratio supplied to a combustion carburetor