Clutch-to-clutch power-on downshifting in a motor vehicle automatic transmission
US4653351A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 1986 |
| Grant date | Mar 31, 1987 |
| Priority date | — |
| Expiry date | Feb 12, 2006 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2061/0477
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A clutch-to-clutch power-on downshift in a motor vehicle automatic transmission is effected by reducing the torque capacity of the off-going clutching device to permit the transmission input speed to increase toward a target speed which it will finally attain subsequent to the shift; increasing the torque capacity of the off-going clutching device and preparing the on-coming clutching device when the input speed approaches its target speed so that the input speed is held near the target speed by the time the on-coming clutching device is prepared to transmit torque; and concurrently applying and releasing the on-coming and off-going clutching device to complete the shift. Since the input speed is substantially at its target value when the exchange of clutching devices occurs, a high quality shift with minimal driveline torque disruption results.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.