Fluid flowmeter
US4282751A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 1979 |
| Grant date | Aug 11, 1981 |
| Priority date | — |
| Expiry date | Aug 29, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F5/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A low pressure drop air flowmeter (10) for an automobile engine is disclosed. The meter contains a main air flow passage (24), a relatively small venturi (20) to receive a portion of the air flow, pressure ports (98a and 120) for sensing stagnation and static pressure and a set of swirl vanes (22) disposed adjacent the outlet of the venturi and operative to impart a swirl to the remainder of the air in the main passage, thereby creating a reduced pressure at the venturi outlet for amplifying the pressure difference between the stagnation and static pressure without appreciably increasing the pressure drop across the flowmeter. A tertiary passage (28) provides a path of fluid communication between points upstream and downstream of the swirl vanes. This passage includes a flow restricting throat (29) which is manually calibrated during or after assembly. Air exiting the tertiary passage impinges upon the swirl to modulate the vortex velocities. This arrangement results in a fluid flowmeter having a characteristic pressure drop which is less than that of a conventional device, particularly at high flow rates. Also disclosed is a solenoid valve (48) operative in the auto-referencing mo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.