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US4449397A
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Apparatus for measuring the mass of a pulsating medium flowing in a flow cross-section
Assignee: Robert Bosch GmbH
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Filing: 1982-08-17
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Granted: 1984-05-22
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Expires: 2002-08-17
Abstract
Abstract An apparatus for measuring the mass of a pulsating medium flowing in a flow cross-section, in particular for measuring the aspirated air mass of internal combustion engines. The apparatus includes a temperature-dependent measuring resistor, whose temperature and/or resistance is regulated in accordance with the mass of a flowing medium. The measurement signal (U S ) representing the mass of the medium can be influenced in accordance with the flow direction by use of a pressure-sensing element which has corresponding electrical contacts and when there is a flow reversal the pressure-sensing element, via a correction circuit, suppresses the delivery of the measurement signal (U S ) to an electronic control unit. By use of the correction circuit it is also possible to subtract the amount measured during a reverse flow from the measurement signal made during flow in the desired flow direction. As a result, an error in the measurement signal (U S ) during pulsating flow is prevented.
Inventors
- 👤 Heinz Lauterbach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:35
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/68; G01F1/696
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
93 words
An apparatus for measuring the aspirated air mass of internal combustion engines, which represents a pulsating flowing medium, comprising at least one temperature-dependent measuring resistor disposed in the flow cross-section, the temperature and resistance of which is regulated in accordance with the flowing mass and a regulator output measurement signal (U S ), a pressure-sensing element which is subjected to the flow medium, said pressure-sensing element producing an output which influences the measurement signal (U S ) representing the flowing mass of medium in accordance with the direction of flow of the medium.
Claim 2
Independent Claim
93 words
An apparatus for measuring the aspirated air mass of internal combustion engines, which represents a pulsating flowing medium, comprising at least one temperature-dependent measuring resistor disposed in the flow cross-section, the temperature and resistance of which is regulated in accordance with the flowing mass and a regulator output measurement signal (U S ), a pressure-sensing element which is subjected to the flow medium, said pressure-sensing element producing an output which influences the measurement signal (U S ) representing the flowing mass of medium in accordance with the direction of flow of the medium.
Claim 3
Dependent Claim
134 words
An apparatus as defined by claim 1, in which said pressure-sensing body includes a carrier body disposed in the the flow of medium, an electrical fixed contact disposed on an end of said carrier body downstream of the flowing medium a movable electrical counterpart contact positioned to cooperate with said fixed contact counter to a restoring force such that when there is a flow of medium in the desired flow direction the fixed contact and said counterpart contact are separated from one another by means of the restoring force and when there is a flow of medium taking place counter to the desired flow direction, the force acting upon the counterpart contact as a result of the backed-up pressure brings the counterpart contact to rest against the fixed contact counter to the restoring force.
Claim 4
Dependent Claim
30 words
An apparatus as defined by claim 2, in which the counterpart contact is disposed on a movable end of a tongue spring fastened on one end of said carrier body.
Claim 5
Dependent Claim
17 words
An apparatus as defined by claim 2, in which the counterpart contact is disposed on a diaphragm.
Claim 6
Dependent Claim
28 words
An apparatus as defined by claim 1 in which the pressure-sensing element has an inherent frequency which is approximately equal to the pulsation frequency of the medium flow.
Claim 7
Dependent Claim
68 words
An apparatus as defined by claim 1, 2, 3, 4 or 5 in which the influence exerted on the measurement signal (U S ) by the pressure-sensing element is effected such that at a pressure of the medium which characterizes a medium flow occurring counter to the desired flow direction of the medium, the measured amount is subtracted from the measurement signal of the desired medium flow direction.
Claim 8
Dependent Claim
61 words
An apparatus as defined by claim 1, 2, 3, 4 or 5 in which the influence exerted on the measurement signal (U S ) by the pressure-sensing element is effected such that at a pressure of the medium which characterizes a medium flow occurring counter to the desired flow direction of the medium, the measurement signal (U S ) is suppressed.
References Cited (Backward Citations)
US4264961A
Cited
US4404846A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-22 | 1987-11-21 | 1988-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-22 | 1991-11-21 | 1992-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-22 | 1995-11-21 | 1996-05-22 | $7700.00 | Window Closed / Lapsed |