Speed change control system in automatic transmission
US5191814A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jul 31, 1991 |
| Grant date | Mar 9, 1993 |
| Priority date | — |
| Expiry date | Jul 31, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S477/906
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A control system in an automatic transmission for controlling the change-over of the three speed change patterns which are a speed change pattern having a cross gear ratio on a low speed side, a speed change pattern having a cross gear ratio on a high speed side and a speed change pattern having a normal gear ratio. According to this controlling system, when one of the three speed change pattern is selected based one a throttle opening and a vehicle speed, and when it is judged that the gear shift from a speed range in the present speed change pattern to a speed range in the selected speed change pattern falls under on of prohibited conditions, e.g., requiring engagement and/or disengagement of three or more frictional engaging elements for the gear shift, the gear shift is performed using a temporary speed change pattern (including the present speed change pattern) including a speed range not falling under the prohibited conditions. Thereafter, the pattern selection is repeated and the change-over between speed change pattern is performed under a gear shift condition not falling under the prohibited conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.