Method of determining rubbing friction torque in a motor vehicle powertrain
US6874360B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 2003 |
| Grant date | Apr 5, 2005 |
| Priority date | — |
| Expiry date | Sep 23, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L3/26
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of determining the rubbing friction torque involves characterizing fuel cutoff engine deceleration, and calculating the rubbing friction torque for any combination of engine speed and powertrain temperature is calculated in accordance with a base point rubbing friction torque RFTbase determined at a base powertrain temperature Tbase and fuel cutoff characterization data. The calibration data characterizing fuel cutoff engine deceleration is obtained by alternately enabling and cutting off engine fuel delivery to cycle the engine speed between specified set points, and measuring and recording the engine deceleration during intervals of fuel cutoff. The rubbing friction torque RFTtest at a given test temperature Ttest is calculated according to where DECELtest and DECELbase are the fuel cutoff engine decelerations at the test and base points, respectively, and PFTtest, and PFTbase are the pumping friction torques at the test and base points, respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.