Speed change control method for an automatic transmission
US5624351A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 1995 |
| Grant date | Apr 29, 1997 |
| Priority date | — |
| Expiry date | Jun 22, 2015 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2306/24
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A speed change control method for an automatic transmission, which can achieve a smooth skip downshifting even when a driver depresses an accelerator pedal slowly in kickdown. An electronic control unit 6 calculates, at the time when a predetermined time period elapses from the time when a downshifting command from a fourth speed to a third speed is outputted, a difference between the throttle valve opening degree .theta..sub.t1 at that time and the throttle valve opening degree .theta..sub.ts at the time when the downshifting command is outputted, and a change rate (.dwnarw..sub.t1)' of the throttle valve opening degree at the time when the predetermined time period elapses. If the calculated difference is larger than the threshold value .DELTA..theta. and the calculated change rate is higher than the threshold value .DELTA.(.theta.)' (S10, S11), the electronic control unit 6 outputs a command for canceling the command for downshifting from the fourth speed to the third speed, which has already been outputted (S12), and outputs a command for downshifting from the fourth speed to a second speed (S13).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.