Method for improving shift quality in an automatic transmission
US8690730B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 2009 |
| Grant date | Apr 8, 2014 |
| Priority date | — |
| Expiry date | Jul 25, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/20018
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A method is provided for improving shift quality in an automatic transmission. In many automatic transmissions, the shift quality during lift foot upshifts is unsatisfying. Generally, two types of complaints concerning shift quality are known: harsh feel right after the shift order and bump at the synchronization of the shift. In order to provide an automatic transmission which overcomes these two problems, a first and a second positive torque requests are initiated on upshift coasts. This measure improves the global shift feel by controlling the engine toque level at shift order and at synchronization: the engine torque level at the beginning of the gear shift is smoothly decreased to reduce the initial bump and is controlled at the synchronization to reduce the amplitude of underlap when the clutch capacity is rising.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.