Viscous link drive for fluid flowmeter
US4428231A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 30, 1981 |
| Grant date | Jan 31, 1984 |
| Priority date | — |
| Expiry date | Nov 30, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/78
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A low pressure drop hot film mass air flowmeter (10) for an automotive engine is disclosed. The flowmeter includes a main air flow passage (20), a fixed contoured flow nozzle (22) disposed in the main air flow passage to establish a localized pressure differential thereacross and, a closed circuitous recirculation path (40) disposed adjacent the main air flow passage and in fluid communication therewith through an inlet port (42) disposed upstream of the flow nozzle and an outlet port (44) disposed downstream from the flow nozzle. Pressure differential at the ports establishes a substantially laminar control flow therebetween within the recirculation path which, in turn, by viscous action, establishes a recirculation flow (67) within the recirculation path. A constant temperature thermal anemometer (54) includes a hot film probe (56) and a temperature compensating probe (58) positioned to sense the recirculating air within the recirculation path. In the preferred embodiment of the invention, a second contoured flow nozzle (96) is disposed within the recirculation path to facilitate flow sensing therein. The anemometer generates an output signal representative of total mass air flow…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.