Electronic feedback EGR valve
US4566423A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 1983 |
| Grant date | Jan 28, 1986 |
| Priority date | — |
| Expiry date | Dec 20, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S137/907
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A vacuum operated EGR valve/controller having a vacuum signal responsive diaphragm converted to operate the EGR poppet valve. A flow limiting orifice is provided upstream of the valve and a flow sensing pressure tap provided intermediate the valve and the orifice. Flow pressure is sensed by a piezoresistive transducer which gives an electrical signal indicative thereof. In one embodiment, the transducer is stationary and flow sensing tube is extended to the valve body. In a second embodiment, the transducer is mounted on the diaphragm for movement therewith and flow sensing is internal through the valve actuator. In another embodiment, a flow sensing orifice is provided downstream of the valve and the transducers has a reference and dynamic probe for sensing the differential of flow pressure on opposite sides of the sensing orifice. In another embodiment, plates attached to the diaphragm form a flow pressure sensing chamber and the transducer tube is received through the plate rail and is sealed by a flexible seal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.