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US5014668A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and system for adjusting the lambda value

Assignee: Robert Bosch GmbH
•
Filing: 1989-02-23
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Granted: 1991-05-14
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Expires: 2009-02-23
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Abstract

Abstract A method and a system for adjusting the lambda value of an air/fuel mixture to be supplied to an internal combustion engine wherein a throttle flap is adjusted in each case in such a manner that lean operation is obtained in a lower load range and a stoichiometric operation (lambda=1) is obtained in an upper load range.

Inventors

  • 👤 Martin Klenk
  • 👤 Ernst Linder
  • 👤 Winfried Moser

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 19:37
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1438; F02D41/1477; F02D41/1479; F02D41/1486

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 178 words
A method of adjusting a lambda value of an air-fuel mixture to be supplied to an internal combustion engine of a motor vehicle having an accelerator pedal, the internal combustion engine having a throttle flap actuator, said method comprising the step of adjusting the throttle flap actuator in accordance with a respective value of an accelerator pedal position signal in such a manner that an air volume to be supplied to the internal combustion engine provides for obtaining a lean air-fuel mixture when the respective value of the accelerator pedal position signal is below a threshold value of the accelerator pedal position signal, that is when the accelerator pedal is in a position corresponding to a lower load range of the internal combustion engine, and for obtaining a stoichiometric air-fuel mixture, at least during steady-state operation, when the respective value of the accelerator pedal position signal is above the threshold value of the accelerator pedal position signal, that is when the accelerator pedal is in a position corresponding to an upper load range of the internal combustion engine.
Claim 2
Independent Claim 178 words
A method of adjusting a lambda value of an air-fuel mixture to be supplied to an internal combustion engine of a motor vehicle having an accelerator pedal, the internal combustion engine having a throttle flap actuator, said method comprising the step of adjusting the throttle flap actuator in accordance with a respective value of an accelerator pedal position signal in such a manner that an air volume to be supplied to the internal combustion engine provides for obtaining a lean air-fuel mixture when the respective value of the accelerator pedal position signal is below a threshold value of the accelerator pedal position signal, that is when the accelerator pedal is in a position corresponding to a lower load range of the internal combustion engine, and for obtaining a stoichiometric air-fuel mixture, at least during steady-state operation, when the respective value of the accelerator pedal position signal is above the threshold value of the accelerator pedal position signal, that is when the accelerator pedal is in a position corresponding to an upper load range of the internal combustion engine.
Claim 3
Dependent Claim 49 words
A method as set forth in claim 1, wherein a transition from a lean operation to a stoichiometric operation and conversely is effected when a fluctuation of the accelerator pedal position signal drops below a predetermined fluctuation range of the accelerator pedal position signal with a predetermined time interval.
Claim 4
Dependent Claim 68 words
A method as set forth in claim 1, wherein the threshold value of the accelerator pedal position signal is selected to be dependent on a rotational speed of the internal combustion engine in such a manner that the threshold value is substantially such that further opening of a throttle flap does not result in any further significant increase in an air volume admitted at a respective rotational speed.
Claim 5
Dependent Claim 34 words
A method as set forth in claim 1, wherein said adjusting step includes adjusting of a throttle flap by rotational speed-dependent values when the threshold value of the accelerator pedal position signal is exceeded.
Claim 6
Independent Claim 178 words
A system for adjusting a lamba value of an air-fuel mixture to be supplied to an internal combustion engine of a motor vehicle having an accelerator pedal, the internal combustion engine having a throttle flap actuator, said adjusting system comprising means for adjusting the throttle flap actuator in accordance with a respective value of an accelerator pedal position signal in such a manner that an air volume to be supplied to the internal combustion engine provides for obtaining a lean air-fuel mixture when the respective value of the accelerator pedal position signal is below a threshold value of the accelerator pedal position signal, that is when the accelerator pedal is in a position corresponding to a lower load range of the internal combustion engine, and for obtaining a stoichiometric air-fuel mixture, at least during steady-state operation, when the respective value of the accelerator pedal position signal is above the threshold value of the accelerator pedal position signal, that is when the accelerator pedal is in a position corresponding to an upper load range of the internal combustion engine.
Claim 7
Independent Claim 178 words
A system for adjusting a lamba value of an air-fuel mixture to be supplied to an internal combustion engine of a motor vehicle having an accelerator pedal, the internal combustion engine having a throttle flap actuator, said adjusting system comprising means for adjusting the throttle flap actuator in accordance with a respective value of an accelerator pedal position signal in such a manner that an air volume to be supplied to the internal combustion engine provides for obtaining a lean air-fuel mixture when the respective value of the accelerator pedal position signal is below a threshold value of the accelerator pedal position signal, that is when the accelerator pedal is in a position corresponding to a lower load range of the internal combustion engine, and for obtaining a stoichiometric air-fuel mixture, at least during steady-state operation, when the respective value of the accelerator pedal position signal is above the threshold value of the accelerator pedal position signal, that is when the accelerator pedal is in a position corresponding to an upper load range of the internal combustion engine.
Claim 8
Dependent Claim 56 words
An adjusting system as set forth in claim 5, wherein said adjusting means includes comparator means for effecting a transition from a lean operation to a stoichiometric operation and conversely when a fluctuation of the accelerator pedal position signal drops below a predetermined fluctuation range of the accelerator pedal position signal within a predetermined time period.
Claim 9
Dependent Claim 36 words
An adjusting system as set forth in claim 5, wherein said adjusting means includes transition means for effecting a gradual transition within a predetermined time period from a lean operation to a stoichiometric operation and conversely.
Claim 10
Dependent Claim 39 words
An adjusting system as set forth in claim 5, wherein said adjusting means includes an adjusting signal memory for storing a set of adjusting values for lean and stoichiometric operations retrievable by values of the accelerator pedal position signal.
Claim 11
Dependent Claim 48 words
An adjusting system as set forth in claim 5, wherein said adjusting means comprises means for outputting an adjusting signal for adjusting the throttle flap actuator for a stoichiometric operation, a lambda value being controlled to 1 during a time interval in which the adjusting signal is output.
Claim 12
Dependent Claim 52 words
An adjusting system as set forth in claim 9, further comprising control means for additionally controlling the lambda value to a lean value predetermined according to values of operational variables during time intervals in which said adjusting means outputs adjusting signal for adjusting the throttle flap actuator to a lean operation position.

References Cited (Backward Citations)

US4434768A Cited
US4594984A Cited
DE3341720A1 Cited
JPS61123735A Cited
JPS62103447A Cited
US4771752A Cited
EP0272814A2 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-05-13 1994-11-12 1995-05-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-05-13 1998-11-12 1999-05-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-05-13 2002-11-12 2003-05-14 $7700.00 Window Closed / Lapsed

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