Hydraulic control device for an automatic transmission
US4934218A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 4, 1989 |
| Grant date | Jun 19, 1990 |
| Priority date | — |
| Expiry date | Jan 4, 2009 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H59/38
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic control device which has a check valve controlling hydraulic pressure to a hydraulic actuator. Hydraulic pressure is selectively supplied to one of plural oil passages having different capacity orifices by a switching valve which switches high speed rotation mode and low speed rotation mode. A hydraulic power source and plural oil passages having different capacity orifices are connected to the switching valve which is controlled by hydraulic pressure varying according to vehicle speed. When rotation of the input shaft is low, the switching valve is connected to the oil passage having small capacity orifice, then hydraulic pressure is supplied to the hydraulic actuator through the orifice of small capacity. At this stage, as centrifugal force working on the ball in the check valve is low, the check valve is closed by even small amount of oil supply through the small capacity orifice, and raises hydraulic pressure in the actuator, so the clutch is engaged smoothly. When rotation of the input shaft is high, the switching valve is connected to the oil passage having the large capacity orifice, then hydraulic pressure is supplied to the hydraulic actuator through the large …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.