EP0079041A2 - Automotive air-fuel ratio control system - Google Patents
Automotive air-fuel ratio control system Download PDFInfo
- Publication number
- EP0079041A2 EP0079041A2 EP19820110128 EP82110128A EP0079041A2 EP 0079041 A2 EP0079041 A2 EP 0079041A2 EP 19820110128 EP19820110128 EP 19820110128 EP 82110128 A EP82110128 A EP 82110128A EP 0079041 A2 EP0079041 A2 EP 0079041A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- air
- engine
- vibration
- fuel
- fuel mixture
- 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- Withdrawn
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Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1497—With detection of the mechanical response of the engine
Definitions
- the present invention relates generally to an automotive air-fuel ratio control system and more specifically to a system including an engine vibration sensor which provides real time information enabling the air-fuel ratio to be held on the lean side of stoichimetry in the near vicinity of a so called "best encomony point".
- the engine carburetor (for example) is calibrated to produce an air-fuel ratio of 15:1 when operated on gasoline containing from 0 - 20% alcohol the equivalence ratio will vary from 0.98 (for pure gasoline) to 0.90 (when the fuel contains 20% alcohol). However, / if the amount of alcohol increases to 50% the equivalence ratio falls to 0.78 which is too lean for stable engine operation and the carburetor must be recalibrated..
- LLC Lean Limit Control
- the present invention accordingly features a sensor which senses the engine vibration directly and which outputs a signal indicative thereof to circuitry which upon detecting vibration in excess of a predetermined level, issues a relatively rapid air-fuel mixture enrichment signal until the level of vibration falls below the predetermined level whereupon a relatively slow air-fuel leaning signal is produced. Continuous repetition of the enrichment-leaning signals causes the air-fuel ratio to hunt back and forth over the "best economy point".
- the present invention takes the form of an internal combustion engine equipped with an air-fuel ratio control system comprising, means for forming an air-fuel mixture, a vibration sensor mounted on the body of the engine for directly sensing the vibration of the engine and outputting a signal indicative of the magnitude thereof, and a control circuit associated with the air-fuel mixture forming means which circuit is responsive to the signal so that upon the magnitude of the vibration exceeding a predetermined level, the control circuit enriches the air-fuel mixture formed by the air-fuel mixture means and leans the air-fuel mixture when the magnitude is lower than the predetermined level.
- an embodiment of the present invention is shown in which an internal combustion engine 10 is equipped with an induction system 12 including an air flow meter 14, a throttle chamber 16 and throttle valve position sensor 18.
- the induction system 12 further includes a fuel injection system 20 comprised of a plurality of injectors 22, a fuel pump 24 which inducts fuel from a fuel tank 26 via a filter 28, a pressure regulator valve 30 and an injection control unit 32.
- the control unit 32 receives data inputs from the air flow meter 14, throttle position sensor 18, an engine distributor 34 and an engine vibration sensor 36 which is attached to the engine proper so as to be directly exposed to the vibration thereof.
- the engine is also equipped with an exhaust system 38 including an oxidizing type catalytic converter 40.
- Fig. 2 shows in block diagram form the injection control unit 32 shown in Fig. 1.
- the input from the vibration sensor 36 (which may sense any one of engine acceleration, displacement or vibration frequency) outputs a signal "P" which is fed to a low pass filter 42.
- This circuit smooths the signal and outputs a signal "Q" to a compensation/operation unit 44 which senses the peak value Q max of signal "Q” and compares same with a predetermined value (viz., slice level S).
- the comparison/operation unit Upon the value of Q max exceeding the slice level the comparison/operation unit functions to generate a first rapid fuel enrichment command signal R 1 (in this instance a pulse width increment command signal of +10% per 0.2 sec.) until the fuel being combusted in the engine becomes sufficiently rich to reduce the engine vibration to a level that the value of Q max falls below the slice level S, whereupon a relatively slow mixture leaning signal R 2 is produced (in this instance a injection pulse width decrement signal of -10% per sec).
- the command signals R 1 and R 2 are fed to a injection pulse generating unit 46.
- This unit functions to determine the basic pulse width of the energization pulses fed to the fuel injectors 22 in view of inputs indicative of engine rotation speed (RPM), air induction quantity, throttle valve position and engine coolant temperture (temperature sensor not shown), and modify same under the influence of the command signals R 1 and R 2 .
- the air-fuel ratio indicated by "A” is a critical one where engine vibration (see curve “a") will rise to a level which will induce physical discomfort and the limit of engine stablity be reached (see curve “b”). That is to say, the major vibration componets under this condition will have frequencies of 400Hz or lower.
- the "best economy point" "B” occurs at an air fuel-ratio which is slightly less than that at which the critial point "A” occurs and at which the levels of HC, CO and NO are acceptably low while the amount of oxygen (0 2 ) contained in the exhaust gases is sufficient to promote secondary oxidization of the HC and CO in the catalytic converter 40.
- control unit may be adapted (via the incorporation of a micro computer or the like) to enable the closed loop control only when the engine is operating within the hatched zone shown in Fig. 4 and disable same when large amounts of power are required such as for hill climbing etc.; such as occur above and to the right of the hatched area.
- the present invention is not limited to the plurality of fuel injectors 22 shown and disclosed but may extend to electronically controlled carburetors, single point fuel injection arrangements and the like.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP176458/81 | 1981-11-05 | ||
| JP17645881A JPS5879642A (ja) | 1981-11-05 | 1981-11-05 | エンジンの空燃比制御装置 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| EP0079041A2 true EP0079041A2 (en) | 1983-05-18 |
Family
ID=16014045
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP19820110128 Withdrawn EP0079041A2 (en) | 1981-11-05 | 1982-11-03 | Automotive air-fuel ratio control system |
Country Status (2)
| Country | Link |
|---|---|
| EP (1) | EP0079041A2 (ja) |
| JP (1) | JPS5879642A (ja) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0140065A1 (de) * | 1983-10-04 | 1985-05-08 | Robert Bosch Gmbh | Elektronische Einrichtung zur Steuerung der Kraftstoffzumessung einer Brennkraftmaschine |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58140449A (ja) * | 1982-02-17 | 1983-08-20 | Nippon Soken Inc | 内燃機関の空燃比制御装置 |
| JPS60125739A (ja) * | 1983-12-09 | 1985-07-05 | Nippon Soken Inc | 内燃機関の空燃比制御装置 |
| JPH0615834B2 (ja) * | 1984-09-07 | 1994-03-02 | マツダ株式会社 | エンジンの制御装置 |
-
1981
- 1981-11-05 JP JP17645881A patent/JPS5879642A/ja active Pending
-
1982
- 1982-11-03 EP EP19820110128 patent/EP0079041A2/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0140065A1 (de) * | 1983-10-04 | 1985-05-08 | Robert Bosch Gmbh | Elektronische Einrichtung zur Steuerung der Kraftstoffzumessung einer Brennkraftmaschine |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5879642A (ja) | 1983-05-13 |
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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 |
|
| 17P | Request for examination filed |
Effective date: 19821103 |
|
| AK | Designated contracting states |
Designated state(s): DE FR GB |
|
| STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN |
|
| 18W | Application withdrawn |
Withdrawal date: 19840326 |
|
| RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: YOSHIMASA, HAYASHI |