US3796199A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuel injection apparatus
Assignee: Robert Bosch GmbH
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Filing: 1973-01-04
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Granted: 1974-03-12
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Expires: 1993-01-04
Abstract
Abstract In a fuel injection apparatus, in order to maintain a constant fuel-air ratio, the position of the movable valve member of a fuel quantity distributor and metering valve is affected by an electromagnet. The intensity of the energizing current for the electromagnet is derived from a comparison between the output of a first and a second bridge circuit. The first bridge circuit contains a temperature-dependent resistance which is located in the engine suction pipe and the resistance value of which is a measure for the flow rate of air. The second bridge circuit contains a temperature-dependent resistance which is located in the distributor and metering valve and the resistance value of which is a measure for the flow rate of fuel.
Inventors
- 👤 H Knapp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:11
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/18; F02D41/187; F02M; F02M69/00; F02M69/16; F02M69/18
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
291 words
In a fuel injection apparatus serving a spark plug-ignited internal combustion engine operating on fuel continuously injected into the suction tube of the engine, said engine having a butterfly valve disposed in said suction tube, said apparatus being of the known type that has (a) a fuel metering valve disposed in the fuel line and having a movable valve member, (b) an electric control apparatus affecting the position of said movable valve member for metering, as a function of engine variables, fuel quantities adapted to the intake air quantities, (c) first electrically operating means for measuring the intake air quantities, (d) a first bridge circuit forming part of said first electrically operating means, (e) a first temperaturedependent resistance exposed to the flow of intake air and forming part of said first bridge circuit, the resistance value of said first temperaTure-dependent resistance being the function of the flow rate of intake air, the improvement comprising A. a second electrically operating means for measuring the metered fuel quantities, B. a second bridge circuit forming part of said second electrically operating means, said second bridge circuit having a characteristic curve of approximately the same course as that of said first bridge circuit, C. a second temperature-dependent resistance exposed to the flow of the metered fuel and forming part of said second bridge circuit, the resistance value of said second temperaturedependent resistance being the function of the flow rate of the metered fuel, D. comparator means connected to said first and second electrically operating means for comparing their output signals and E. means coupled to the output of said comparator means and to said movable valve member for adjusting the position of the latter as a function of the output signals of said comparator means.
Claim 2
Dependent Claim
291 words
In a fuel injection apparatus serving a spark plug-ignited internal combustion engine operating on fuel continuously injected into the suction tube of the engine, said engine having a butterfly valve disposed in said suction tube, said apparatus being of the known type that has (a) a fuel metering valve disposed in the fuel line and having a movable valve member, (b) an electric control apparatus affecting the position of said movable valve member for metering, as a function of engine variables, fuel quantities adapted to the intake air quantities, (c) first electrically operating means for measuring the intake air quantities, (d) a first bridge circuit forming part of said first electrically operating means, (e) a first temperaturedependent resistance exposed to the flow of intake air and forming part of said first bridge circuit, the resistance value of said first temperaTure-dependent resistance being the function of the flow rate of intake air, the improvement comprising A. a second electrically operating means for measuring the metered fuel quantities, B. a second bridge circuit forming part of said second electrically operating means, said second bridge circuit having a characteristic curve of approximately the same course as that of said first bridge circuit, C. a second temperature-dependent resistance exposed to the flow of the metered fuel and forming part of said second bridge circuit, the resistance value of said second temperaturedependent resistance being the function of the flow rate of the metered fuel, D. comparator means connected to said first and second electrically operating means for comparing their output signals and E. means coupled to the output of said comparator means and to said movable valve member for adjusting the position of the latter as a function of the output signals of said comparator means.
Claim 3
Dependent Claim
76 words
An improvement as defined in claim 1, wherein said first and second electrically operating means constitute closed, separate first and second regulator circuits, respectively, each regulator circuit including current regulator means for so readjusting the electric current flowing through said temperature-dependent resistances as to maintain the latter at approximately constant temperatures, whereby the intensity of current flowing through said first and second regulator circuits represents a measure for the flow rate of air and fuel, respectively.
Claim 4
Dependent Claim
53 words
An improvement as defined in claim 2, including an operational amplifier constituting said comparator means and an electromagnet forming part of said means coupled to the output of said comparator means, the intensity of the magnetic field of said electromagnet being variable as a function of the output signals of said operational amplifier.
Claim 5
Dependent Claim
29 words
An improvement as defined in claim 2, each regulator circuit includes a separate amplifier, the input of which is connected to the diagonal junctions of its associated bridge circuit.
Claim 6
Dependent Claim
25 words
An improvement as defined in claim 4, wherein said current regulator means includes means connecting the output of said amplifier to its associated bridge circuit.
Claim 7
Dependent Claim
46 words
An improvement as defined in claim 2, including a potentiometer and means varying said potentiometer as a function of the position of said butterfly valve, said potentiometer forming part of said first regulator circuit for detuning the electric current flowing therethrough to effect a lambda -correction.
Claim 8
Dependent Claim
46 words
An improvement as defined in claim 2, including an additional temperature-dependent resistance exposed to the temperature of the engine coolant and forming part of said first regulator circuit for detuning the electric current flowing therethrough to effect a correction for the warm run of the engine.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-11 | 1977-09-10 | 1978-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-11 | 1981-09-10 | 1982-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-11 | 1985-09-10 | 1986-03-12 | $7700.00 | Window Closed / Lapsed |