System for controlling oxygen concentration in exhaust gas and exhaust gas cleaning system employing the same
US5379586A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 1992 |
| Grant date | Jan 10, 1995 |
| Priority date | — |
| Expiry date | Sep 21, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
An exhaust gas cleaning system has a catalyzer provided in the exhaust passage of the engine and an adsorbent provided upstream from the catalyzer. The adsorbent temporarily adsorbs unburned hydrocarbons emitted in large amounts immediately after the engine is started. The system provides an amount of air required to substantially eliminate unburned hydrocarbons, based on the temperature of the adsorbent and the oxygen concentration in exhaust gas upstream from the catalyzer. An air supplying unit is provided upstream from the adsorbent. A temperature sensor is provided for the adsorbent. An oxygen sensor is provided at the inlet of the catalyzer. A control unit calculates the amount of air (oxygen) necessary for the catalyzer to convert the unburned hydrocarbons released from the adsorbent, based on signals from the temperature sensor and the oxygen sensor and the exhaust flow rate. The control unit accordingly controls the air supplying unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.