US4644922A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for controlling the overrun mode of operation of an internal combustion engine
Assignee: Robert Bosch GmbH
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Filing: 1985-10-22
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Granted: 1987-02-24
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Expires: 2005-10-22
Abstract
Abstract The invention is directed to a method and an apparatus for controlling the overrun mode of operation of an internal combustion engine, wherein instantaneous values of the relevant negative speed change of the internal combustion engine are sensed and evaluated to control the overrun mode. In this arrangement, a higher resume speed which is selected on commencement of the overrun mode and reduced to a lower speed limit after a predetermined time function, can be shifted additionally in dependence on the negative speed change. Further, to keep an internal combustion engine from stalling, the actual value of the negative speed change can be compared with a predetermined desired value; if it exceeds that value, the decision for a resume of fuel delivery can be made without delay.
Inventors
- 👤 Otto Glockler
- 👤 Dieter Gunther
- 👤 Ulrich Steinbrenner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:28
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/04; F02D41/12; F02D41/123; F02D41/126; F02B; F02B1/00; F02B1/02; F02B1/04
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
129 words
Method of controlling the fuel metering apparatus of an internal combustion engine in the overrun mode of operation with a resume speed threshold n RE (t) above which the fuel metered to the engine is interrupted and below which fuel is again metered to the engine, the method comprising: that the resume speed threshold n RE (t) runs between an upper speed threshold n o and a lower speed threshold n 1 ; and, in the overrun mode of operation starting said resume speed threshold n RE (t) at a value n o and reducing said resume speed threshold n RE (t) to a value n 1 with the instantaneous value of n RE (t) being dependent upon the first derivative dn/dt of the rotational speed of the engine.
Claim 2
Dependent Claim
129 words
Method of controlling the fuel metering apparatus of an internal combustion engine in the overrun mode of operation with a resume speed threshold n RE (t) above which the fuel metered to the engine is interrupted and below which fuel is again metered to the engine, the method comprising: that the resume speed threshold n RE (t) runs between an upper speed threshold n o and a lower speed threshold n 1 ; and, in the overrun mode of operation starting said resume speed threshold n RE (t) at a value n o and reducing said resume speed threshold n RE (t) to a value n 1 with the instantaneous value of n RE (t) being dependent upon the first derivative dn/dt of the rotational speed of the engine.
Claim 3
Dependent Claim
25 words
The method of claim 1, said threshold n o and said threshold n 1 being dependent upon at least one operating parameter of the engine.
Claim 4
Dependent Claim
14 words
The method of claim 2, said operating parameter being the temperature of the engine.
Claim 5
Dependent Claim
16 words
The method of claim 2, said operating parameter being the actual rotational speed of the engine.
Claim 6
Dependent Claim
30 words
The method of claim 1, said threshold n o and said threshold n 1 being dependent upon the temperature of the engine and the actual rotational speed of the engine.
Claim 7
Dependent Claim
23 words
The method of claim 5, wherein only the dynamic resume speed n o is increased as the negative rotational speed change -dn/dt increases.
Claim 8
Dependent Claim
89 words
The method of claim 5, wherein the resume speed is increased as the negative speed change -dn/dt increases, and wherein a first threshold (-dn/dt) 1 and a second threshold (-dn/dt) 2 are provided, the method comprising the further steps of supplying a decremented quantity of fuel to the engine when the drop in rotational speed of the engine passes below said first threshold (-dn/dt) 1 and supplying an incremented quantity of fuel when the drop in rotational speed of the engine passes above said second threshold (-dn/dt) 2 .
Claim 9
Dependent Claim
54 words
The method of claim 7, wherein the engine is equipped with lambda control means for determining the air/fuel ratio, the method comprising the further step of: blocking said control means when changing the amount of fuel supplied from the desired value in dependence upon the negative speed change during the overrun mode of operation.
Claim 10
Dependent Claim
54 words
The method of claim 1, wherein there is a lower rotational-speed dependent boundary value for the first derivative (dn/dt) of the actual rotational speed n, the method comprising the further step of resuming the metering of fuel to the engine in the overrun mode of operation when passing beneath said rotational-speed dependent boundary value.
Claim 11
Dependent Claim
123 words
Apparatus for controlling the overrun mode of operation of an internal combustion engine in dependence upon the instantaneous rotational speed of the engine and a resume speed threshold characteristic, the apparatus comprising: throttle-valve sensor means for detecting the position of the throttle-valve; speed sensor means for detecting the instantaneous value of the rotational speed (n) of the engine; speed comparator means for determining if the engine speed exceeds the threshold; overrun cutoff circuit means for determining a fuel cutoff signal or a fuel metering signal; and, comparator and function circuit means for evaluating said negative speed change for comparing resume speed thresholds or for displacing said thresholds, said comparator and function circuit means including circuit means for generating the negative speed change (-dn/dt).
Claim 12
Dependent Claim
123 words
Apparatus for controlling the overrun mode of operation of an internal combustion engine in dependence upon the instantaneous rotational speed of the engine and a resume speed threshold characteristic, the apparatus comprising: throttle-valve sensor means for detecting the position of the throttle-valve; speed sensor means for detecting the instantaneous value of the rotational speed (n) of the engine; speed comparator means for determining if the engine speed exceeds the threshold; overrun cutoff circuit means for determining a fuel cutoff signal or a fuel metering signal; and, comparator and function circuit means for evaluating said negative speed change for comparing resume speed thresholds or for displacing said thresholds, said comparator and function circuit means including circuit means for generating the negative speed change (-dn/dt).
Claim 13
Dependent Claim
45 words
The apparatus of claim 10, said comparator and function circuit means further including means for changing individual thresholds or the resume speed time dependent function (n RE ) in dependence upon the relevant negative speed change (-dn/dt) and, as required, in dependence upon the temperature.
Claim 14
Dependent Claim
59 words
The apparatus of claim 10, comprising a differential comparator means for providing a predetermined desired value of a negative speed change curve in dependence upon the relevant instantaneous speed (n); and, said differential comparator means including means for comparing said desired value to the relevant actual value of the negative speed change for producing a fuel delivery resume signal.
Claim 15
Dependent Claim
76 words
The apparatus of claim 12, comprising comparator switching means for adjusting the flow of metered fuel after fuel delivery has resumed or by open throttle valve, said comparator switching means comprising comparator means for comparing the actual negative speed change to predetermined fixed threshold values of negative speed change; and, timing means connected to the output of said comparator switching means for imparting a time dependent character to the adjustment of said flow of metered fuel.
Claim 16
Dependent Claim
27 words
The apparatus of claim 13, comprising additional switching means for disabling the mixture control means of the engine in response to an output of said timing means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-02-23 | 1990-08-25 | 1991-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-23 | 1994-08-25 | 1995-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-23 | 1998-08-25 | 1999-02-24 | $7700.00 | Window Closed / Lapsed |