Exhaust passage switching unit and method for internal combustion engine
US6321533A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 23, 2000 |
| Grant date | Nov 27, 2001 |
| Priority date | — |
| Expiry date | May 23, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A hydrocarbon adsorption apparatus is provided in an exhaust passage of an internal combustion engine. The hydrocarbon adsorption apparatus is equipped with a main passage, a switching valve for opening and closing the main passage, and a bypass passage for bypassing the main passage. The switching valve is coupled to a diaphragm of a diaphragm mechanism. A variable chamber in the diaphragm mechanism is connected to an intake manifold through a negative pressure feed line and a vacuum switching valve. When the vacuum switching valve is turned on, a negative pressure is supplied to the variable pressure chamber so that the diaphragm is deflected. In response to the deflection of the diaphragm, the switching valve is closed. The state of the switching valve is judged based on a tendency of changes in pressure of the negative pressure feed line when the vacuum switching valve is turned on.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.