Hydraulic control apparatus for an automatic transmission
US7628729B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 22, 2006 |
| Grant date | Dec 8, 2009 |
| Priority date | — |
| Expiry date | Jan 2, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S477/906
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic control apparatus, provided with a manual shift valve that outputs a forward range pressure and a reverse range pressure, and a linear solenoid valve that outputs an engagement pressure to the hydraulic servo that engages during reverse travel when energized, includes a fourth clutch relay valve that is interposed between the linear solenoid valve and the hydraulic servo. The fourth clutch relay valve communicates an engagement pressure of the linear solenoid valve to the hydraulic servo by locking in the normal position when a signal pressure of the solenoid valve is input, and communicates a reverse range pressure to the hydraulic servo by being switched to a fail position by the reverse range pressure during a failure in which the fourth clutch relay valve is de-energized. Thereby, it is possible to establish a reverse speed during a failure in which the solenoid valve is de-energized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.