Malfunction diagnosis device for engine speed controller
US5701866A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 1996 |
| Grant date | Dec 30, 1997 |
| Priority date | — |
| Expiry date | Dec 20, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
To appropriately detect malfunction of an air quantity adjusting valve in any type of case, an electronic control type throttle valve is disposed in an air intake pipe of an engine. An ISC valve which is duty controlled by an ECU is disposed in a bypass passage which bypasses the throttle valve. A CPU within the ECU establishes a drive duty ratio of the ISC valve to control engine speed in a target speed region during idling of the engine. Additionally, in a case where the drive duty ratio exceeds a predetermined control range (0 to 100%), the CPU controls idle speed by the throttle valve. Accordingly, in a case where throttle aperture is larger than a predetermined value TAH, or in a case where throttle aperture is smaller than a predetermined value TAL (where TAH>TAL), the CPU determines that an opening side malfunction or a closing side malfunction has occurred in the ISC valve.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.