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US4718015A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and apparatus for controlling an internal combustion engine

Assignee: Robert Bosch GmbH
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Filing: 1985-05-20
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Granted: 1988-01-05
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Expires: 2005-05-20
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Abstract

Abstract The invention is directed to a method for the cylinder-group specific control of a multi-cylinder internal combustion engine and an apparatus for carrying out the method for cylinder-group specific optimization of the efficiency of the internal combustion engine. The control strategy includes a first step for generating time-dependent signals to influence the air ratio lambda of the air-fuel mixture supplied to at least any two cylinder groups each made up of at least one cylinder. The air ratio lambda is influenced such that the air ratio is modified in a cylinder-group specific manner and that the mean air ratio of the air-fuel mixture supplied to all cylinders is maintained constant. A second step follows to detect the reaction of the internal combustion engine to the signals of the first step, this reaction manifesting itself in a modification of an output quantity. Then follows a third step to influence the efficiency of the individual cylinder groups of the internal combustion engine in accordance with the results of the second step. This ensures that each cylinder group or each cylinder receives an air-fuel mixture having an air ratio at which efficiency is at a maximum. For a given engine design and for given operating conditions, it is thus possible for the engine to operating in the range of theoretically minimum fuel consumption.

Inventors

  • 👤 Ferdinand Grob
  • 👤 Josef Wahl

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 19:00
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/008; F02D41/0082; F02D41/02; F02D41/14; F02D41/1401; F02D41/1408

Claims Analysis

Total Claims: 24
Claim 1
Independent Claim 175 words
Method for controlling operating characteristic quantities of a multi-cylinder internal combustion engine with a control strategy for optimizing the efficiency of the engine, the method and control strategy comprising: a first step of generating time dependent signals for modifying the air ratio lambda of the operating mixture conducted to at least any two desired groups of cylinders wherein each group includes at least one cylinder, said air ratio lambda being modified for one cylinder group in a direction so as to lean the operating mixture and said air ratio lambda being modified for an other cylinder group in a direction so as to enrich the operating mixture while at the same time holding the mean air ratio of the operating mixture conducted to all cylinders at least approximately constant; a second step of detecting the reaction of the engine to said signals as manifested by a change of an output quantity; and, a third step of influencing the efficiency of the individual cylinder groups of the engine pursuant to the results of the second step.
Claim 2
Dependent Claim 175 words
Method for controlling operating characteristic quantities of a multi-cylinder internal combustion engine with a control strategy for optimizing the efficiency of the engine, the method and control strategy comprising: a first step of generating time dependent signals for modifying the air ratio lambda of the operating mixture conducted to at least any two desired groups of cylinders wherein each group includes at least one cylinder, said air ratio lambda being modified for one cylinder group in a direction so as to lean the operating mixture and said air ratio lambda being modified for an other cylinder group in a direction so as to enrich the operating mixture while at the same time holding the mean air ratio of the operating mixture conducted to all cylinders at least approximately constant; a second step of detecting the reaction of the engine to said signals as manifested by a change of an output quantity; and, a third step of influencing the efficiency of the individual cylinder groups of the engine pursuant to the results of the second step.
Claim 3
Dependent Claim 24 words
The method of claim 1, said third step including changing the air ratio for the specific cylinder group for each one of said groups.
Claim 4
Dependent Claim 16 words
The method of claim 2, the air ratio for the specific cylinder group being oppositely changed.
Claim 5
Dependent Claim 27 words
The method of claim 1, comprising comparing said change of the output quantity as a reaction of the engine in said first step to a threshold value.
Claim 6
Dependent Claim 29 words
The method of claim 4, comprising storing the lambda values specific for each group of cylinders after said output quantity change of the engine drops below said threshold value.
Claim 7
Dependent Claim 26 words
The method of claim 4, comprising storing the amplitude of the time-dependent signals after said output quantity change of the engine drops below said threshold value.
Claim 8
Dependent Claim 24 words
The method of claim 4, comprising storing the duration of injection after said output quantity change of the engine drops below said threshold value.
Claim 9
Dependent Claim 28 words
The method of claim 1, comprising repeatedly applying said steps to different cylinder groups whereby the number of applications is at least determined by the number of cylinders.
Claim 10
Dependent Claim 29 words
The method of claim 1, comprising combining the cylinder groups from different cylinders whereby the number of the combinations is determined at least by the number of the cylinders.
Claim 11
Dependent Claim 39 words
The method of claim 1, said first step including influencing the air ratio lambda specific for each group of cylinders by varying the quantity of fuel delivered to the cylinder groups while the inducted air is held approximately constant.
Claim 12
Dependent Claim 34 words
The method of claim 10, wherein the metered fuel is injected by means of at least a fuel injection valve and is varied over the duration of injection and the time point of injection.
Claim 13
Dependent Claim 47 words
The method of claim 11, comprising oppositely modifying the durations or points of injection specific for each group of cylinders so that the total of the durations of injection as the sum of the individual durations of injection of the individual cylinders takes on a constant value.
Claim 14
Dependent Claim 28 words
The method of claim 10, wherein the metered fuel is injected by means of at least a fuel injection valve and is varied over the duration of injection.
Claim 15
Dependent Claim 47 words
The method of claim 13, comprising oppositely modifying the durations or points of injection specific for each group of cylinders so that the total of the durations of injection as the sum of the individual durations of injection of the individual cylinders takes on a constant value.
Claim 16
Dependent Claim 29 words
The method of claim 10, wherein the metered fuel is injected by means of at least a fuel injection valve and is varied over the time point of injection.
Claim 17
Dependent Claim 47 words
The method of claim 15, comprising oppositely modifying the durations or points of injection specific for each group of cylinders so that the total of the durations of injection as the sum of the individual durations of injection of the individual cylinders taken on a constant value.
Claim 18
Dependent Claim 19 words
The method of claim 1, comprising detecting a change in the torque of the engine in said second step.
Claim 19
Dependent Claim 17 words
The method of claim 17, comprising utilizing the rotational speed of the engine as an output quantity.
Claim 20
Dependent Claim 27 words
The method of claim 1, comprising precontrolling, by means of a characteristic field, the air ratio lambda of the operating mixture which is conducted to the engine.
Claim 21
Dependent Claim 17 words
The method of claim 19, comprising adapting the characteristic field values specific for each group of cylinders.
Claim 22
Dependent Claim 28 words
The method of claim 1, comprising controlling the mean air ratio of the operating mixture conducted to all cylinders to a value adjustable in dependence upon operating parameters.
Claim 23
Dependent Claim 200 words
Apparatus for carrying out a method of controlling operating characteristic quantities of a multi-cylinder internal combustion engine with a control strategy for optimizing the efficiency of the engine, the apparatus comprising: microcomputer and peripheral equipment means for optimizing the efficiency of the engine; first function means for generating time-dependent signals for modifying the air ratio lambda of the operating mixture conducted to at least any two desired groups of cylinders wherein each group includes at least one cylinder, said first function means including means for modifying said air ratio lambda for one cylinder group in a direction so as to lean the operating mixture and said air ratio lambda being modified for another cylinder group in a direction so as to enrich the operating mixture while at the same time holding the mean air ratio of the operating mixture conducted to all cylinders at least approximately constant; second function means for detecting the reaction of the engine to said signals of said first function means as manifested by a change of an output quantity; and, third function means for influencing the efficiency of the individual cylinder groups of the engine pursuant to the results obtained from said second function means.
Claim 24
Dependent Claim 200 words
Apparatus for carrying out a method of controlling operating characteristic quantities of a multi-cylinder internal combustion engine with a control strategy for optimizing the efficiency of the engine, the apparatus comprising: microcomputer and peripheral equipment means for optimizing the efficiency of the engine; first function means for generating time-dependent signals for modifying the air ratio lambda of the operating mixture conducted to at least any two desired groups of cylinders wherein each group includes at least one cylinder, said first function means including means for modifying said air ratio lambda for one cylinder group in a direction so as to lean the operating mixture and said air ratio lambda being modified for another cylinder group in a direction so as to enrich the operating mixture while at the same time holding the mean air ratio of the operating mixture conducted to all cylinders at least approximately constant; second function means for detecting the reaction of the engine to said signals of said first function means as manifested by a change of an output quantity; and, third function means for influencing the efficiency of the individual cylinder groups of the engine pursuant to the results obtained from said second function means.

References Cited (Backward Citations)

US4301780A Cited
US4387429A Cited
GB2034930A Cited
US4489690A Cited
US4483300A Cited
US4495920A Cited
US4532592A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-01-04 1991-07-06 1992-01-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-01-04 1995-07-06 1996-01-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-01-04 1999-07-06 2000-01-05 $7700.00 Window Closed / Lapsed

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