Hydraulic control system for automatic transmissions used in vehicles
US5888169A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 3, 1997 |
| Grant date | Mar 30, 1999 |
| Priority date | — |
| Expiry date | Oct 3, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S477/906
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
The hydraulic control system for an automatic transmission having a plurality of friction elements includes a pressure regulator which regulates hydraulic pressure produced by an oil pump, a plurality of valves selectively supplying hydraulic pressure to the plurality of friction elements, and a pressure controller controlling and selectively supplying hydraulic pressure to a plurality of pressure control lines operationally connected to the plurality of valves and at least one of the plurality of valves. The plurality of valves include a first valve operationally controlled by hydraulic pressure in a first one of the pressure control lines to pass the hydraulic pressure output by the pressure controller to at least one of the plurality of friction elements in each operational range except a first speed stage of a drive range. A second valve is operationally controlled by hydraulic pressure in a second one and third one of the pressure control lines to selectively pass the hydraulic pressure output from the first valve to a first and second friction element in the drive range. A control switch valve in the plurality of valves is operationally controlled by a fourth one of the press…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.