Patent US4420971A successfully refreshed from Google Patents.
US4420971A
Expired / Lapsed
US
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Device for flowthrough rate measurement in an internal combustion engine
Assignee: Robert Bosch GmbH
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Filing: 1981-06-18
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Granted: 1983-12-20
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Expires: 2001-06-18
Abstract
Abstract A device is proposed for measuring the flowthrough rate in an internal combustion engine, particularly for measuring the air throughput in the intake tube. The device has a measurement bridge functioning on the principle of constant-temperature control, and also a regulating deivce for the total bridge current during the burn-off phase of the hot wire or hot film as one of the bridge resistors. The essential feature is that the bridge circuit assembly comprises at least three voltage dividers; for the purpose of regulating the electric current in the burn-off phase and during measurement operation, respective control voltages are picked up between two different voltage dividers.
Inventors
- 👤 Peter Rapps
- 👤 Ulrich Drews
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:21
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/68; G01F1/696; G01F1/698; F; F02; F02D; F02D41/00; F02D41/02; F02D41/18; F02D41/187; G01F1/6983
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
126 words
A burnout device for flowthrough rate measurement for measuring the air throughput in the intake tube of an internal combustion engine comprising: a bridge circuit assembly having at least three voltage dividers connected to respective control voltages, a heated resistance material disposed in the flow of the medium included in one of said voltage dividers and at which a control voltage is connected for regulating the electric current through said resistance material, means for selectively connecting either one of the remaining two of said voltage dividers in conjunction with said one of said voltage dividers for a measurement or a burn-off operation, and control means responsive to said bridge circuit assembly for controlling said control voltage for regulating the electric current to said heated resistance material.
Claim 2
Dependent Claim
126 words
A burnout device for flowthrough rate measurement for measuring the air throughput in the intake tube of an internal combustion engine comprising: a bridge circuit assembly having at least three voltage dividers connected to respective control voltages, a heated resistance material disposed in the flow of the medium included in one of said voltage dividers and at which a control voltage is connected for regulating the electric current through said resistance material, means for selectively connecting either one of the remaining two of said voltage dividers in conjunction with said one of said voltage dividers for a measurement or a burn-off operation, and control means responsive to said bridge circuit assembly for controlling said control voltage for regulating the electric current to said heated resistance material.
Claim 3
Dependent Claim
25 words
A device as defined by claim 1, wherein during burn-off said heated resistance material is independent of the temperature of the medium to be measured.
Claim 4
Dependent Claim
39 words
A device as defined by claim 1, wherein said control voltages are delivered to a regulating amplifier and that in accordance with a further control variable one of said respective control voltages influences the output of the regulating amplifier.
Claim 5
Dependent Claim
43 words
A device as defined by claim 3, wherein the regulating amplifier includes two operational amplifiers to which said respective control voltages can be delivered at the input side and which on the output side is selectively connected via diodes with a coupling point.
Claim 6
Independent Claim
32 words
A device as defined by at least one of the claims 1 or 4, wherein one of said voltage dividers is uncoupled by means of a switch from an operational voltage line.
Claim 7
Independent Claim
35 words
A device as defined by at least one of the claims 1 or 4, wherein a pickup point of said bridge circuit assembly is subjected, during measurement operation of the device, to a predetermined potential.
Claim 8
Dependent Claim
16 words
A device as defined by claim 1, wherein said heated resistance material is a hot wire.
Claim 9
Dependent Claim
16 words
A device as defined by claim 1, wherein said heated resistance material is a hot film.
References Cited (Backward Citations)
US4196622A
Cited
US4341114A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-19 | 1987-06-20 | 1987-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-19 | 1991-06-20 | 1991-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-19 | 1995-06-20 | 1995-12-20 | $7700.00 | Window Closed / Lapsed |