Hydraulic pressure control apparatus for an automatic transmission
US5782711A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 1996 |
| Grant date | Jul 21, 1998 |
| Priority date | — |
| Expiry date | Dec 18, 2016 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2061/0087
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic pressure control apparatus for an automatic transmission including a microprocessor-based control unit for controlling hydraulic pressure supplied to hydraulic servos of friction engagement elements. The control apparatus calculates a target hydraulic pressure P.sub.TA for a condition at the start of the inertia phase in accordance with the input torque, and a gradient based on the target hydraulic pressure and a predetermined time t.sub.TA. A first up-sweep of hydraulic pressure is performed by the apparatus with the gradient. A relatively gradual gradient .delta.P.sub.TA is set based on a target rotation change rate for the input rotational speed to provide a predetermined change amount when the hydraulic pressure becomes the target hydraulic pressure P.sub.TA. The control apparatus performs a second up-sweep with the gradient .delta.P.sub.TA. When the rotational speed change .DELTA.N of the input rotation becomes a rotation change start-determining rotational speed dN.sub.S, the control apparatus feedback-controls the hydraulic pressure with a predetermined gradient while referring to the input rotation change. Further, the control apparatus detects the target shift …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.