Shift control apparatus of automatic transmission
US5938563A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 18, 1998 |
| Grant date | Aug 17, 1999 |
| Priority date | — |
| Expiry date | Feb 18, 2018 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2312/02
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A shift control apparatus of an automatic transmission executes a transient control of an engagement pressure of a first speed selecting friction element when a first speed is selected after a higher speed is once selected during a change from a neutral range to a forward drive range. A band brake pressure for selecting the second speed is rapidly increased at a first moment. A forward clutch pressure for selecting the first speed is increased at a second moment delaying to the first moment by a predetermined period adjusted to a line pressure lowered period. The forward clutch pressure is pre-charged during a period between the first and second moments, then being hold for a preset time period at a return spring corresponding pressure adjusted by a leaning control, and being increased by a slope adjusted by the leaning control for a predetermined period to establish the second speed by the engagement of the forward clutch. Then, the band brake pressure is rapidly decreased and further decreased by a slope to disengage the band brake in order to establish the first speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.