Control apparatus for device having dead band, and variable valve system
US7004128B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 2002 |
| Grant date | Feb 28, 2006 |
| Priority date | — |
| Expiry date | Jul 23, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/8242
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A control unit employed in a variable valve timing apparatus vibrates a control signal for controlling an oil-pressure control valve. If the vibration center of the duty value of the control signal for driving the oil-pressure control valve lies in a dead band, the vibration takes the duty value to the outside of the dead center temporarily. Thus, even if the center value of the control signal lies in the dead band, the valve timing of the oil-pressure control valve changes with variations in control signal. As a result, the width of the dead band appears small or to have a value of zero. Accordingly, the response characteristic of variations in valve timing to the variations in control signal is improved. The vibration of the control signal is also effective for detection of a width of the dead band.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.