Partial prefill of clutch for coast downshift conditions in a vehicle
US8965653B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 2013 |
| Grant date | Feb 24, 2015 |
| Priority date | — |
| Expiry date | Aug 28, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/60
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A vehicle transmission includes a plurality of oncoming clutches that are hydraulically-actuated. A controller is operatively connected to the plurality of oncoming clutches. An algorithm stored on and executable by the controller causes the controller to determine if at least one predefined coast condition is met and identify the plurality of oncoming clutches configured to be engageable during a downshift event from an initial gear ratio to respective other gear ratios. The initial gear ratio is greater than each of the respective other gear ratios. The algorithm causes the controller to generate a first pressure command to at least partially pressurize a first one of the oncoming clutches to a first staging pressure (PS1) if the at least one predefined coast condition is met prior to the downshift event. The first staging pressure (PS1) is defined as a first return spring pressure (PR1) minus a first variable correction factor (CF1).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.