Engine idle speed control system for automotive vehicle
US5216895A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 3, 1992 |
| Grant date | Jun 8, 1993 |
| Priority date | — |
| Expiry date | Sep 3, 2012 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60H1/3208
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
In an engine idle speed control system associated with an air conditioner provided with an evaporator for evaporating a refrigerant compressed by a compressor actuated or deactuated by an engine near an evaporator freeze limit temperature, the engine idle speed is increased under consideration of thermal load applied to the compressor whenever the compressor is being actuated. The compressor 21 is deactuated when the temperature of air having passed through the evaporator 22 drops below a predetermined value, and actuated when the same temperature rises beyond another higher predetermined value. Whenever the compressor 21 has been deactuated, the time interval between the deactuation and the actuation of the compressor is measured. If the measured time interval is relatively short, since this indicates a relatively high thermal load applied to the compressor, the engine idle speed is increased. However, if the measured time interval is relatively long, since this indicates a relatively low thermal load, the engine idle speed is not increased, thus improving the fuel consumption rate and the compressor durability without frequently actuating and deactuating the compressor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.