US3699935A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fail-safe fuel injection control arrangement for internal combustion engines
Assignee: Robert Bosch GmbH
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Filing: 1970-12-11
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Granted: 1972-10-24
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Expires: 1990-12-11
Abstract
Abstract An electrically controlled control element determines fuel injection per operating cycle. The control circuit determining position of control element receives signals indicating gas pedal position, engine speed, and feedback signal indicating control element position. Each of these signals varies with corresponding parameter in such a manner that interruption of the signal causes minimum fuel injection. Additional limiting circuits within control system also designed to cause minimum fuel injection during circuit failure.
Inventors
- 👤 Karl-Heinz Adler
- 👤 Johannes Locher
- 👤 Rudolf Lemanczyk
- 👤 Edgar Schonart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:51
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/30; F02D41/38; F02D2250/00; F02D2250/38
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
215 words
In an internal combustion engiNe, a fail-safe fuel injection control arrangement, for furnishing a predetermined minimum fuel injection upon failure of system components, comprising, in combination, injection means having an electrically activated control element controlling by its position along a predetermined path the quantity of fuel injected per operating cycle of said engine, said control element having a null position causing said predetermined minimum fuel injection; activating means moving said control element along said predetermined path in correspondence to fuel control signals, said activating means moving said control element to said null position in response to a predetermined fuel control signal; a plurality of sensing means, each furnishing a sensed signal corresponding to a predetermined operating parameter of said engine; voltage supply means furnishing a supply voltage, and electrical control circuit means energized by said voltage supply means, having inputs connected to said sensing means, and a control output connected to said activating means for furnishing said fuel control signals in response to said sensed signals, said electrical control circuit means and said sensing means cooperating in such a manner that failure in one of said sensing means resulting in absence of one of said sensed signals causes the furnishing of said predetermined fuel control signal at said control output, thereby causing minimum fuel injection.
Claim 2
Dependent Claim
215 words
In an internal combustion engiNe, a fail-safe fuel injection control arrangement, for furnishing a predetermined minimum fuel injection upon failure of system components, comprising, in combination, injection means having an electrically activated control element controlling by its position along a predetermined path the quantity of fuel injected per operating cycle of said engine, said control element having a null position causing said predetermined minimum fuel injection; activating means moving said control element along said predetermined path in correspondence to fuel control signals, said activating means moving said control element to said null position in response to a predetermined fuel control signal; a plurality of sensing means, each furnishing a sensed signal corresponding to a predetermined operating parameter of said engine; voltage supply means furnishing a supply voltage, and electrical control circuit means energized by said voltage supply means, having inputs connected to said sensing means, and a control output connected to said activating means for furnishing said fuel control signals in response to said sensed signals, said electrical control circuit means and said sensing means cooperating in such a manner that failure in one of said sensing means resulting in absence of one of said sensed signals causes the furnishing of said predetermined fuel control signal at said control output, thereby causing minimum fuel injection.
Claim 3
Dependent Claim
28 words
An arrangement as set forth in claim 1, wherein said electrical control circuit means further furnish said predetermined fuel control signal in the absence of said supply voltage.
Claim 4
Dependent Claim
74 words
An arrangement as set forth in claim 2, wherein said electrical control circuit means comprises first circuit means having inputs connected to said sensing means and furnishing an output signal at a first circuit output as a function of said sensed signals and in accordance with the characteristic curves of said engine; control amplifier means having a reference input connected to said first circuit output and a control output connected to said activating means.
Claim 5
Dependent Claim
69 words
An arrangement as set forth in claim 3, further comprising control element position sensing means furnishing a feedback signal corresponding to said position of said control element; and wherein said control amplifier means further comprises a feedback input connected to said control element position sensing means, whereby said control amplifier furnishes said fuel control signal as a function of the difference between said feedback signal and said reference input.
Claim 6
Dependent Claim
18 words
An arrangement as set forth in claim 4, wherein said first circuit means comprise high-gain D.C. amplifier means.
Claim 7
Dependent Claim
29 words
An arrangement as set forth in claim 5, wherein said feedback signal has an amplitude varying inversely with the position of said control element away from said null position.
Claim 8
Dependent Claim
48 words
An arrangement as set forth in claim 6, wherein said feedback signal is a feedback voltage having a predetermined maximum amplitude when said fuel control element is in said null position and a predetermined minimum amplitude when said fuel control element is in the position causing maximum injection.
Claim 9
Dependent Claim
28 words
An arrangement as set forth in claim 2, wherein said sensing means comprise speed sensing means furnishing a speed voltage varying inversely with the speed of said engine.
Claim 10
Dependent Claim
55 words
An arrangement as set forth in claim 8, wherein said speed sensing means comprise inductive speed sensor means furnishing a predetermined number of pulses per engine rotation; and speed converter means connected to said inductive speed sensor means and furnishing a D.C. speed voltage having an amplitude inversely proportional to the frequency of said pulses.
Claim 11
Dependent Claim
85 words
An arrangement as set forth in claim 9, wherein said speed converter means comprise pulse forming means connected to said speed sensor means; and monostable multivibrator means connected to said pulse forming means and furnishing, at a multivibrator output, an inverted multivibrator output pulse sequence, said multivibrator output pulse sequence having a pulse repetition frequency corresponding to engine speed, and pulses of substantially equal width and amplitude; and filter means connected to said multivibrator output and furnishing, at a filter output, said D.C. speed voltage.
Claim 12
Dependent Claim
60 words
An arrangement as set forth in claim 10, further comprising an excess speed control switching stage having an input connected to said speed sensing means and an output connected to said activating means, said speed control switching stage furnishing said predetermined fuel control signal upon receipt of a speed signal corresponding to an engine speed exceeding a predetermined maximum speed.
Claim 13
Dependent Claim
103 words
An arrangement as set forth in claim 8, wherein said engine comprises an accelerator; wherein said sensing means comprise acceleration sensing means furnishing an acceleration signal varying as a function of the position of said accelerator relative to an accelerator null position and having a predetermined minimum acceleration signal amplitude at said accelerator null position; wherein said electrical control circuit means comprises a high-gain D.C. inverting amplifier, said high-gain D.C. inverting amplifier furnishing said predetermined fuel control signal in response to said predetermined minimum acceleration signal in the presence of a speed signal corresponding to an engine speed exceeding a predetermined minimum speed.
Claim 14
Dependent Claim
46 words
An arrangement as set forth in claim 12, wherein said acceleration sensing means comprise inductive sensor means; and clamping circuit means connected to said inductive sensor means and furnishing said predetermined minimum acceleration signal in the presence of acceleration signals less than said predetermined acceleration signal.
Claim 15
Dependent Claim
77 words
An arrangement as set forth in claim 13, wherein said clamping circuit means comprise first voltage divider means having a voltage divider tap furnishing said predetermined minimum acceleration signal; first transistor means having a control circuit and an output circuit; means connecting said output circuit to said voltage divider tap and said control circuit to said inductive sensor means; and wherein said first transistor means is blocked for acceleration signals less than said predetermined minimum acceleration signal.
Claim 16
Dependent Claim
72 words
An arrangement as set forth in claim 14, further comprising second voltage divider means having a second voltage divider tap furnishing a predetermined maximum acceleration signal; second transistor means having a second transistor output circuit and a second transistor control circuit; means connecting said second transistor output circuit to said tap of said second voltage divider means and said second transistor control circuit to said tap of said first voltage divider means.
Claim 17
Dependent Claim
87 words
An arrangement as set forth in claim 12, where in said high-grain D.C. amplifier means comprise feedback circuit means having a feedback circuit impedance and input circuit means having an input circuit impedance, whereby the gain of said high-gain D.C. amplifier means varies in dependence upon the relationship between said feedback circuit impedance means and said input circuit impedance means; further comprising speed network means interconnected between said speed sensing means and said input circuit, for changing said input circuit impedance as a function of engine speed.
Claim 18
Dependent Claim
38 words
An arrangement as set forth in claim 16, wherein said feedback circuit, said input circuit, and said speed network each comprise resistances; and wherein the resistance of said speed network means varies as a function of engine speed.
Claim 19
Dependent Claim
62 words
An arrangement as set forth in claim 16, wherein said input circuit is a first resistance; and wherein said speed network means comprise a second resistance and second switching means connected to said second resistance and connecting said second resistance in parallel with said first resistance when said speed signal corresponds to an engine speed less than a predetermined minimum engine speed.
Claim 20
Dependent Claim
52 words
An arrangement as set forth in claim 18, wherein said speed network further comprises a third resistance, and third switching means connected to said third resistance and connecting said third resistance in parallel with said first resistance when said speed signal corresponds to an engine speed exceeding a predetermined maximum engine speed.
Claim 21
Dependent Claim
31 words
An arrangement as set forth in claim 19, wherein said second and third switching means respectively comprise second and third diode, respectively connected in series with said second and third resistance.
Claim 22
Dependent Claim
84 words
An arrangement as set forth in claim 20, wherein said voltage supply means comprise a first and second voltage supply terminal; wherein said speed network means comprise first voltage divider means connected between said first voltage supply terminal and a first terminal of said first resistance, and having a first voltage divider tap; and wherein said third diode has a cathode connected to the input of said high-gain D.C. amplifier means; further comprising means connecting said third resistance to said first voltage divider tap.
Claim 23
Dependent Claim
26 words
An arrangement as set forth in claim 21, wherein said means connecting said third resistance to said first voltage divider tap comprise a temperature compensating diode.
Claim 24
Dependent Claim
62 words
An arrangement as set forth in claim 22, wherein said speed network means comprise second voltage divider means connected from said first terminal of said first resistance to said second voltage divider terminal, and having a second voltage divider tap; further comprising means connecting said second voltage divider tap with one terminal of said second resistance in series with said second diode.
Claim 25
Dependent Claim
37 words
An arrangement as set forth in claim 23, wherein said means connecting said second voltage divider tap to a terminal of said second resistance connected in series with said second diode comprise an additional temperature compensating diode.
Claim 26
Dependent Claim
24 words
An arrangement as set forth in claim 24, wherein said first and second voltage divider means respectively comprise a first and second adjustable resistor.
Claim 27
Dependent Claim
81 words
An arrangement asset forth in claim 16, further comprising output connecting means connecting the output of said D.C. amplifier means to said activating means in such a manner that a minimum D.C. amplifier output signal causes maximum fuel injection; further comprising output clamping means connected to the output of said D.C. amplifier means for clamping said D.C. amplifier output signal to a predetermined minimum output signal in the presence of D.C. amplifier output signals less than said predetermined minimum output signal.
Claim 28
Dependent Claim
98 words
An arrangement as set forth in claim 26, wherein said D.C. amplifier means comprise a final stage having a load resistance; wherein said voltage supply means comprise a first and second voltage supply terminal; and wherein said output clamping means comprise output voltage divider means connected from said first to said second voltage supply terminal and having a voltage divider output tap; further comprising an output diode having an anode connected to said load resistance and a cathode connected to said output voltage divider tap, the voltage at said output voltage divider tap constituting said fuel control signal.
Claim 29
Dependent Claim
18 words
An arrangement as set forth in claim 27, wherein said output voltage divider means comprise a variable resistor.
Claim 30
Dependent Claim
29 words
An arrangement as set forth in claim 28, wherein said feedback resistance is connected from said output voltage divider tap to the input of said high-gain D.C. amplifier means.
Claim 31
Dependent Claim
33 words
An arrangement as set forth in claim 29, further comprising additional fuel limiting circuit means connected to said output voltage divider tap for decreasing the maximum permissible fuel injection at high engine speeds.
Claim 32
Dependent Claim
95 words
An arrangement as set forth in claim 30, wherein said additional fuel limiting circuit means comprise a fuel limiting resistance; and switching means connected to said fuel limiting resistance and sAid voltage divider tap of said output voltage divider means in such a manner that said additional fuel limiting resistance is connected in parallel with a predetermined portion of said output voltage divider means when said switching means is in a conductive condition; and further circuit means switching said switching means to said conductive condition when said engine speed exceeds a second predetermined engine speed.
Claim 33
Dependent Claim
87 words
An arrangement as set forth in claim 31, wherein said switching means comprise a diode having a cathode connected to said output voltage divider tap and an anode connected to said fuel limiting resistance; and wherein said further circuit means comprise transistor means having an output circuit connected to said fuel limiting resistance and a base circuit connected to said speed sensing means in such a manner that said diode is blocked when said transistor means is conductive and is conductive when said transistor means is blocked.
Claim 34
Dependent Claim
28 words
An arrangement as set forth in claim 32, further comprising a feedback resistor connected from the collector of said transistor means to the base of said transistor means.
Claim 35
Dependent Claim
19 words
An arrangement as set forth in claim 33, wherein said feedback resistor and fuel limiting resistor are variable resistors.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-24 | 1976-04-24 | 1976-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-24 | 1980-04-24 | 1980-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-24 | 1984-04-24 | 1984-10-24 | $7700.00 | Window Closed / Lapsed |