Control apparatus for hydraulically operated vehicular transmission
US6068575A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1997 |
| Grant date | May 30, 2000 |
| Priority date | — |
| Expiry date | Sep 23, 2017 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2306/24
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
At downshifting, hydraulic pressure of hydraulic clutch on engaging side (ON clutch pressure) is increased when an input and output speed ratio ("Gratio") has fallen below a predetermined value YGDNS. YGDNS is variably set depending on the vehicle speed and the engine temperature so that it becomes a lower value at a high vehicle speed than at a low vehicle speed, and a higher value at a low engine temperature than at a high temperature. When a downshifting command to a still lower speed stage is issued during downshifting control (when FTBD=1), a downshifting completion processing is performed in the course of the downshifting control (step in S111). Oil pressure in a hydraulic engaging element on the disengaging side QDNOFF and oil pressure in a hydraulic engaging element on the engaging side QDNON are switched to the oil pressures at the time of completion of downshifting, to thereby complete the first step downshifting control at an early time. In order to prevent unnecessary speed changing at the time of tire locking, downshifting is prohibited when deceleration of the vehicle speed has exceeded a predetermined value (when a setting of FLOCK=1 is made).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.