Device for sensing an oxygen concentration in gaseous body with a pump current supply circuit and an air/fuel ratio control system using an oxygen concentration sensing device
US4665874A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 1986 |
| Grant date | May 19, 1987 |
| Priority date | — |
| Expiry date | Sep 22, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/417
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An oxygen concentration sensing device and an air/fuel ratio control system for an internal combustion engine which include a pair of solid electrolyte members having oxygen ion permeability which are arranged to face each other to form a restricted region between them. One of the solid electrolyte members is operative as an oxygen pump element when a pump current is supplied across the electrodes thereof. The sensing device is provided with a current supply part including a limit command circuit which generates a current stop command signal when the magnitude of the pump current exceeds a reference limit level. With the current stop command signal, the supply of the pump current is stopped so as to prevent an overcurrent to the oxygen pump element. The air/fuel ratio control system includes an air/fuel ratio detection part and an air/fuel ratio control part operated by an air/fuel ratio detection signal. The detection of the air/fuel ratio and the supply of the pump current are stopped under a predetermined operating condition of the engine.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.