Control method of and system thereof for inversely proportionally raising and lowering servo hydraulic pressure, based on input torque, for engaging and disengaging frictional elements in automatic transmission
US5368531A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Nov 27, 1992 |
| Grant date | Nov 29, 1994 |
| Priority date | — |
| Expiry date | Nov 27, 2012 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H61/061
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A method is provided for the control of servo hydraulic pressure in an automatic transmission. Servo hydraulic pressure is adapted to engage or release first and second frictional engagement elements arranged in such a relationship that, upon shifting from one particular speed stage to another, one of the first and second frictional engagement elements is released while the other is engaged. The servo hydraulic pressure, engaging one frictional engagement element, is linearly lowered in a torque phase during a shift so it releases the one frictional engagement element, responsive to a rise in the servo hydraulic pressure to the frictional engagement element to be engaged, to maintain an inversely proportional relationship between the servo hydraulic pressure being raised and that being released.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.