Control system for changing servo timings of hydraulic pressure based on a torque input in automatic transmission
US5403248A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Nov 27, 1992 |
| Grant date | Apr 4, 1995 |
| Priority date | — |
| Expiry date | Nov 27, 2012 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2061/044
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A control system is provided for servo hydraulic pressure in an automatic transmission having planetary gear mechanisms. First and second frictional engagement devices, whose servo pressures are reversed in feed/drain relationship between desired two high speed stages, are controlled by a shift valve and a directional control valve. The shift valve is switched by a first solenoid. The directional control valve is interposed in a servo hydraulic pressure feed/drain line communicating the shift valve with the first frictional engagement device and is controlled by a second solenoid. The first and second solenoids are controlled by an electronic control unit in accordance with a shift position detected by a detector, whereby the timings of feed or drain of the servo hydraulic pressures to or from the first and second frictional engagement devices are changed by predetermined relative amounts, respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.