Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3906909 A
Publication typeGrant
Publication dateSep 23, 1975
Filing dateDec 14, 1973
Priority dateOct 24, 1970
Publication numberUS 3906909 A, US 3906909A, US-A-3906909, US3906909 A, US3906909A
InventorsGiampaolo Garcea
Original AssigneeAlfa Romeo Spa
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Internal combustion engine of the fuel injection type having means for reducing the emission of unburned products with the exhaust gases
US 3906909 A
Abstract
For an internal combustion engine of the fuel injection type, improved means are disclosed, aiming at reducing the emission of an unburned fraction in the exhaust gases, so as to diminish the causes of pollution of the atmosphere. According to the improvement, fuel feed cut-off means and air feed cut-off means are provided to cut off both the fuel feed and the air feed when the conventional fuel feed regulating means and air throttling means are in "idling" position and the engine speed is higher than the idling speed.
Images(1)
Previous page
Next page
Description  (OCR text may contain errors)

United States Patent 1191 1111 3,906,909

Garcea Sept. 23, 1975 15 INTERNAL COMBUSTION ENGINE OF THE 2,741,233 4/1956 McKinley 123/97 B FUEL INJECTION TYPE HAVING MEANS 53:2 :26 3; h 8

, ennesson FOR REDUCING THE EMISSION F 3,463,130 8/1969 Reichardt 61 al 123/97 B UNBURNED PRODUCTS WITH THE 3,517,653 6/1970 Arigu et al. 123/97 B EXHAUST GASES 3,570,460 4/1971 Rabus 123/97 B 3,670,706 6/1972 Fujisawu 123/97 B [75] Inventor Gama Italy 3,688,752 9/1972 Baudry 123/97 B [73] Assignee: Alfa Romeo, S.p.A., Milan, Italy 3,727,591 4/1973 Sudo 123/97 B 3,795,237 3/1974 Denton 123/97 B [22] F11ed: Dec. 14, 1973 [21] Appl. No.; 424,738 Primary ExaminerCharles J. Myhre Assistant ExaminerDavid D. Reynolds Related Application Data Attorney, Agent, or Firml-lolman & Stern [63] Continuation-impart of Ser. No. 191,453, Oct. 21,

a 57 ABSTRACT [30] Foreign Application Priority Data For an internal combustion engine of the fuel injection 061. 24, 1970 Italy 7344/70 type, improved means are disclosed aiming at reducing the emission of an unburned fraction in the ex- 52 123 97 123/119 [23/139 AW haust gases, so as to diminish the causes of pollution [51] Int. Cl. F02D 31/00 of the atmosphere- According to the improvement 3 Field of Search ]23/97 B, 1 19 A, 139 w fuel feed cut-off means and air feed cut-off means are provided to cut off both the fuel feed and the air feed [56] References Cited when the conventional fuel feecl regulating means and UNITED STATES PATENTS air throttling means are in idling position and the 2 395 748 2/1946 M 23/97 B engine speed is higher than the idling speed.

a ory 2,506,511 5/1950 Mallory 123/97 B 3 Claims, 2 Drawing Figures 1 n //l' /l 1 1 1 I i 1 15 I 2 1 l D 36 1 I11 29 45 U will-{11f INTERNAL COMBUSTION ENGINE OF THE FUEL INJECTION TYPE HAVING MEANS FOR REDUCING THE EMISSION OF UNBURNED PRODUCTS WITH THE EXHAUST GASES RELATED APPLICATION This is a continuation in part application of my earlier application Ser. No. 191,453, now abandoned, filed Oct. 21, I971.

BACKGROUND OF THE INVENTION One of the most significant factors contributing towards air pollution and, more particularly in inhabited areas, is the emission, by internal combustion engines of motor vehicles, of exhaust gases which contain a not negligible fraction of unburned products.

It has been shown that a significant fractionof the unburned products is emitted by an engine when the latter is driven to rotation by the transmission unit, thus giving a negative torque: this phenomenon occurs, in actual practice, whenever the driver releases the accelerator pedal, thus closing the throttle and the engine, ,as connected to the vehicle wheels, .is driven to rotation at a rate which exceeds the one attendant to it as a function of the air gasoline mixture drawn into the engine; the resultant braking action is resorted to for decelerating the vehicle run, or to prevent it from accelerating, as it occurs when the vehicle is descending a slope.

It is known that in an engine which is driven at a comparatively high speed when the accelerator pedal is released, carburation difficulties are experienced, due to the high negative pressure obtaining downstream of the throttle and of the small rates of flow of both air and gasoline concerned: in addition, combustion difficulties are also originated inasmuch as the comparative rarefaction of the mixture encourages the phenomenon of extinction of the flame in the neighborhood of the combustion chamber walls. These phenomena, along with others, are responsible for a considerable percentage of unburned fractions in the exhaust gases.

In order to limit the emission of unburned fractions, in internal combustion engines of the fuel injection type, it has been suggested to adopt devices which cut off the fuel injection to the engine when the latter is driven by the vehicle wheels: this approach has the defeet that the gases coming from the oil sump, which is connected to the air suction duct, do not burn and thus soil the interior of the cylinders and are discharged into the atmosphere: a further, but not less serious drawback is that the air drawn into and exhausted from the cylinder, if no combustion takes place, cools the cylinder walls, with the result being difficulties in the combustion and an increase of the emission of unburned fractions whenever the released accelerator pedal is depressed again.

OBJECTS AND SUMMARY OF THE INVENTION An object of the present invention is to reduce the emission of unburned fractions in the exhaust gases of an internal combustion engine of the fuel injection type which is driven to rotation at a rather high rate and with the throttle placed in the idling position.

An additional object of this invention is to render particularly high the braking torque supplied by the engine when the accelerator pedal is released.

According to the invention, an internal combustion engine of the fuel injection type is provided, which comprises a combustion chamber, an intake duct leading to said chamber, fuel injecting means located in said intake duct, fuel feed means connected to said fuel injecting means, regulating means coupled to said fuel feed means to regulate the fuel. feed, air feed means introducing air in the intake duct upstream to the fuel injecting means, throttling means coupled to said air feed means to regulate the air feed concurrently with the operation of said regulating means, fuel feed cut-off means, air feed cut-off means and control means responsive to the concurrent operation of said regulating means and said throttling means and to the engine speed to actuate the fuel feed and air feed cut-off means to cut-off the fuel feed and the air feed when said regulating means and said throttling means are arranged to regulate the fuel feed and the air feed' at the idling values and the engine speed is higher than the idling speed.

Otherwise stated, according to the present invention both the fuel feed and the air feed are cut off when the engine is driven by the vehicle wheels, so that the above mentioned drawbacks encountered in the fuel injection engines which are only provided with fuel feed cut-off means are thus eliminated and. a relevant reduction of unburned fractions in the exhaust gases is obtained.

In order that the present invention may be better understood, two exemplary embodiments thereof will now be described and diagrammatically shown in the accompanying drawings, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatical view, partly in section, of an exemplary embodiment of the invention, and

FIG. 2 is a view, similar to FIG. 1, of an alternative exemplary embodiment of the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS As appears in FIG. 1, an internal combustion engine of the fuel injection type has a combustion chamber 14, an exhaust duct 15 and an intake duct 13, which communicates with a manifold 12, where other intake ducts of every cylinder may open, according to a well known diagram. An air intake pipe,.generally shown at 1, is flanged onto the manifold and to an air filter 51 communicating with the atmosphere. A main internal duct 26 of the pipe 1 is throttled by a throttle 2, whose arbor 3 is rotatably and controllably supported by the pipe walls and is operatively connected to the accelerator pedal (not shown) of the vehicle. An auxiliary idling duct 4 by-passes the throttle 2 and opens downstream of the throttle in registry with a calibrated bore 5. The duct 4 is equipped with an intercepting member consisting of an obturator or valve member 7 which, by an axial movement, can have its portion 6 resting against a corresponding seat 9, thus closing the duct. The obturator 7 is driven by a solenoid 8 which, as it is energized, drives the valve member to contact the seat 9, against the bias of resilient means, not shown, which bring it back to the at rest position shown in the drawing, when the solenoid is not energized. The solenoid has a terminal 11 connected to ground and a terminal 10 connected, through a line 3 1, to a pole of a current generator 29, whose other pole is connected to ground: on the line 31 there are, serially connected, two

switches 32 and 33, respectively. The switch 32 is mechanically ganged with the throttle 2 in the sense that it is closed when the throttle closes the duct 26; the switch 33 is controlled by a device 28, which is conventional per se and, which receives, through a line 30, a signal which is a function of the rotational speed of the engine; as said speed exceeds a predetermined threshold value, above the idling value, the device causes the switch 33 to be closed; when the speed is below said threshold value, the switch is driven to opening.

As shown in FIG. 1, a fuel injecting means 43 is located within the intake duct 13 and has a fuel feed means 44 connected thereto. A regulating means 45 is coupled to the fuel feed means 44 to regulate the fuel feed between minimum and maximum values depending on the position of the accelerator pedal of the vehicle and on the running speed of the engine. More precisely, the regulating means 45 is connected to the throttle 2 so as to regulate the fuel feed at the minimum or idling value when the throttle is closed. A fuel feed cut-off means 41 is also coupled to the fuel feed means 44 to cut off the fuel feed when electrically energized. An electrical lead 42 connects the fuel feed cut-off means 41 to the energizing line 31.

In operation, when the accelerator pedal is released, i.e. the throttle 2 is closed and the regulating means regulates the fuel feed at the minimum of idling value, and the engine rotates at the idling speed, the switch 32 is closed but the switch 33 is open, so that the solenoid 8 is de-energized and the auxiliary duct 4 is open and keeps the air feed at a minimum or idling value; the fuel feed cut-off means 41 also is de-energized. In such a case, if the engine is accelerated, the switch -33 is closed, but the line 31 is nevertheless cut off by the opening of the switch 32 and the solenoid 8 is still deenergized.

Conversely, when the accelerator pedal is released but the engine rotates at a speed higher than the idling speed, the switches 32, 33 are simultaneously closed, so that the solenoid 8 is energized and the 7 closes the duct 4, thus cutting off the air feed. The fuel feed cutoff means 41 also are energized and entirely cut off the fuel feed, so that neither fuel nor air are introduced into the combustion chamber 14 and the exhaust duct 15 discharges only negligible amounts of gases, such as may seep through an imperfect tightness of the throttle 2 and valve member 7. It is to be noted that the switches 32 and 33 of the embodiment shown in FIG. 1 could be actuated by the same actuating means used in the regulating means 45 to regulate the fuel feed as a function of the position of the accelerator pedal and the engine speed.

An additional exemplary embodiment of the invention is shown in FIG. 2 and parts thereof which correspond to those of the embodiment of FIG. 1 have been indicated by similar reference numerals and will not be explained in detail.

In this second embodiment, the bore 5 can be placed alternatingly in communication either with the duct 4 i or a duct 17, according to whether a valve member 21 The valve member 21 is controlled, with the intermediary of a stem 22, by a solenoid 23 which, as it is energized, brings the valve member back to the seat 16 against the bias of resilient means (not shown) which urges the valve member to contact the seat 20 when the solenoid 23 is not fed. A terminal 24 of the solenoid is connected to ground and a terminal 25 is connected, through a line 38, to a pole of the current generator 29, whose other pole is also connected to ground. On the line 38 there are, serially connected, two switches 39 and 40: the switch 40 is connected to the throttle 2 in the sense of being closed as the throttle is closed, while the switch 39 is connected to a diaphragm 35 which can be deformed against the bias of a compression spring 34 and which closes the chamber 36 which communicates, through a duct 37, with the manifold 12. The fuel feed cut-off means 41 also is connected to the energizing line 38 via the line 42.

In operation, when the accelerator pedal is released (or, anyhow, the throttle 2 is closed and the regulating means 45 keeps the fuel feed at the minimum or idling value) and the engine is driven at the idling speed, the switch 40 is closed but the negative pressure in the manifold 12 is not sufficient to overcome the bias of the spring 34 on the diaphragm 35, so that the switch 39 remains open and the solenoid 23 is not energized. The valve member 21 thus remains in the position of FIG. 2, so that the recycling duct 19, 27, 17 is closed and the minimum or idling duct 4, 5 is open. The fuel feed cutoff means 41 also is de-energized.

As the engine is accelerated by depressing the acccelerator pedal, the switch 40 is opened and the operation of the assembly is conventional.

When, conversely, the accelerator pedal is released but the engine is driven at a comparatively high speed of rotation, the negative pressure in the manifold 12 is increased until overcoming the bias of the spring 34, so that the switch 39 is closed and the fuel feed cut-off means 41 and the solenoid 23 are energized to cut off the fuel feed and to move the valve member 21 towards the seat 16 to cut off the idling duct 4,5.

This movement of the valve member 21 causes also the recycling duct 19, 27, 17 to be opened, so that the exhaust gases are recirculated from the exhaust duct 15 to the intake duct 13 and prevent the negative pressure in the intake duct from attaining too high a value, such as to give rise to excessive seepings through the throttle 2 and valve member 21. The recycling duct thus attains the result to improve the cut-off action of the fuel feed and air feed cut-off means 41 and 21. Of course, the bore 5 should have an adequate size so as to prevent an excessive flow of recycled gas, which could lower the magnitude of the negative pressure in the manifold 12 to a value not sufficient to maintain the switch 39 closed. It is also important to notice that the recycling of hot exhaust gases allows a flow of gas in the engine, when no combustion occurs, without experiencing too intensive a cooling of the combustion chamber, whose consequence would be the emission of unburned fractions as the engine resumes its normal operation.

The embodiments shown in the drawings are, as outlined above, mere examples and many modifications can be provided for without thereby departing from the scope of the present invention. More particularly, the control circuits for the solenoid as illustrated can be indifferently applied to either embodiment described herein.

What is claimed is: r

1. An internal combustion engine of the fuel injection type, comprising a combustion chamber, an intake duct leading to said chamber, fuel injecting means located in said intake duct, fuel feed means connected to said fuel injecting means, regulating means coupled to said fuel feed means to regulate the fuel feed, air feed means for introducing air in the intake duct upstream to the fuel injecting means, throttling means coupled to said air feed means to regulate the air feed concurrently with the operation of said regulating means, fuel feed cut-off means, air feed cut-off means and control means responsive to the concurrent operation of said regulating means and said throttling means and to the engine speed to actuate the fuel feed and air feed cutoff means to cut off the fuel feed and the air feed when said regulating means and said throttling means are arranged to regulate the fuel feed and the air feed at the idling values and the engine speed is higher than the idling speed, the air feed means comprising a main duct in which said throttling means is arranged and an auxiliary duct in parallel therewith, said air feed cut-off means being defined by a valve member which is actuated to close said auxiliary dluct when the throttling means closes said main duct and the engine speed is higher than the idling speed, and wherein the combustion chamber is provided with an exhaust duct which is connected to the intake duct via a recycling duct provided with gas recycling cut-off means which normally closes said recycling duct and which is controlled to open said recycling duct when said air feed cut-off means is actuated.

2. The internal combustion engine as claimed in claim 1, in which said valve member is controlled by an electromagnet so as to be moved to the closing position when the electromagnet is energized.

3. The internal combustion engine as claimed in claim 2, in which said electromagnetis fed by a current generator through a line on which there are, serially arranged, a first switch and a second switch, the first switch being connected to the throttling means so as to be closed when the throttling means close said main duct, and the second switch being controlled by a device sensitive to the engine speed so as to be closed when said speed exceeds the idling value.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2395748 *Oct 26, 1945Feb 26, 1946Mallory MarionDegasser for internal-combustion engines
US2506511 *Aug 1, 1946May 2, 1950Mallory Res CoCombined carburetor and degasser
US2741233 *Sep 15, 1955Apr 10, 1956Fred E MckinleyApparatus for preventing release of contaminants from the exhaust of an internal combustion engine
US2940331 *Mar 16, 1959Jun 14, 1960Joseph C LearyAutomatic motive fluid cut-off
US3455260 *Oct 24, 1966Jul 15, 1969SibeCarburettors for internal combustion engines
US3463130 *Oct 24, 1967Aug 26, 1969Bosch Gmbh RobertFuel injection control system
US3517653 *Apr 30, 1968Jun 30, 1970Nissan MotorDevice for interrupting idle fuel circuit of a carburetor
US3570460 *Sep 11, 1969Mar 16, 1971Bosch Gmbh RobertControl system for blocking fuel injection in an internal combustion engine
US3670706 *Jul 6, 1970Jun 20, 1972Nippon Denso CoFuel injection control system for internal combustion engines
US3688752 *Jun 24, 1970Sep 5, 1972Inst Francais Du PetroleDevice for reducing the emission of pollution responsible products by external carburation engines during the deceleration periods
US3727591 *Oct 20, 1970Apr 17, 1973Hitachi LtdFuel supply control system for internal combustion engines
US3795237 *Dec 3, 1971Mar 5, 1974Ford Motor CoCarburetor anti-dieseling and deceleration control
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4015569 *Jan 7, 1976Apr 5, 1977Fuel Injection Development CorporationFuel metering and vaporizing system for internal combustion engines
US4015572 *Jan 7, 1976Apr 5, 1977Fuel Injection Development CorporationCharge forming system for internal combustion engines
US4061119 *Jul 21, 1976Dec 6, 1977Toyota Jidosha Kogyo Kabushiki KaishaExhaust gas recirculation apparatus for an internal combustion engine
US4117814 *Jun 21, 1977Oct 3, 1978Mitsubishi Jidosha Kogyo Kabushiki KaishaIntake regulator for internal combustion engine
US4122812 *Jan 5, 1977Oct 31, 1978Toyota Jidosha Kogyo Kabushiki KaishaExhaust gas recirculation apparatus for an internal combustion engine
US4125099 *Jul 6, 1977Nov 14, 1978Hitachi, Ltd.Carburetor with fuel compensation device
US4128085 *May 16, 1977Dec 5, 1978Nissan Motor Company, LimitedEngine mechanical loss reducing system
US4146594 *Mar 15, 1978Mar 27, 1979Jean RaudFuel flow control device
US4157081 *Jan 18, 1978Jun 5, 1979Nissan Diesel Motor Co., Ltd.Recirculated exhaust gas control device for use in a diesel engine
US4192267 *Sep 22, 1978Mar 11, 1980Texaco Inc.Exhaust gas recycling in an internal combustion engine
US4206730 *Sep 22, 1978Jun 10, 1980Texaco Inc.Method for recycling exhaust gas from an internal combustion engine
US4240395 *Aug 29, 1978Dec 23, 1980Ford Motor CompanyAir/fuel ratio controller
US4243002 *Jun 15, 1978Jan 6, 1981Audi Nsu Auto Union AktiengesellschaftFuel injection system for an internal combustion engine
US4304200 *Feb 28, 1980Dec 8, 1981Audi Nsu Auto Union AktiengesellschaftFuel injection systems for mixture compressing spark-ignition internal combustion engine
US4515124 *Jan 17, 1983May 7, 1985Nissan Motor Company, LimitedEngine control system
US4537169 *May 31, 1983Aug 27, 1985Nippon Soken, Inc.Fuel injection device of diesel engine
US4619230 *Mar 7, 1983Oct 28, 1986Vdo Adolf Schindling AgDevice for disconnecting the feed of fuel to an internal combustion engine
US5022367 *Aug 3, 1990Jun 11, 1991Fuji Jukogyo Kabushiki KaishaEngine brake system of a two-cycle engine for a motor vehicle
US5337715 *Nov 13, 1992Aug 16, 1994Ford Motor CompanyEngine deceleration intake air flow reduction and fuel shut-off control
EP0089409A1 *Nov 23, 1982Sep 28, 1983VDO Adolf Schindling AGFuel cut-off control system in an internal-combustion engine
Classifications
U.S. Classification123/324, 261/DIG.190, 123/325
International ClassificationF02M25/07, F02D21/08, F02M3/045
Cooperative ClassificationF02M25/0772, F02M3/045, F02D41/123, F02D41/0077, F02M25/0724, F02D41/0055, Y02T10/121, Y10S261/19
European ClassificationF02M3/045, F02M25/07V2E, F02M25/07P4V
Legal Events
DateCodeEventDescription
May 19, 1992ASAssignment
Owner name: FIAT AUTO S.P.A., ITALY
Free format text: MERGER;ASSIGNOR:ALFA LANCIA S.P.A. (MERGED INTO);REEL/FRAME:006122/0268
Effective date: 19911120
May 19, 1992AS03Merger
Owner name: ALFA LANCIA S.P.A. (MERGED INTO)
Owner name: FIAT AUTO S.P.A. CORSO GIOVANNI AGNELLI, 200 - TUR
Effective date: 19911120
Feb 12, 1988ASAssignment
Owner name: ALFA LANCIA S.P.A., ARESE, MILAN, ITALY, A CORP. O
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:ALFA ROMEO S.P.A.;REEL/FRAME:004831/0252
Effective date: 19870930
Owner name: ALFA LANCIA S.P.A., A CORP. OF ITALY,ITALY
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ALFA ROMEO S.P.A.;US-ASSIGNMENT DATABASE UPDATED:20100528;REEL/FRAME:4831/252
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ALFA ROMEO S.P.A.;REEL/FRAME:004831/0252