Hydraulic control apparatus for an automatic transmission
US7621837B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 22, 2006 |
| Grant date | Nov 24, 2009 |
| Priority date | — |
| Expiry date | May 9, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S477/906
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic control apparatus for an automatic transmission is provided with a solenoid valve that outputs a signal pressure during a failure and does not output a signal pressure during normal operation and a first clutch apply relay valve that switches between a normal position (the right half position) and a fail position (the left half position) based on this signal pressure are provided. During a failure, fail-safe control is carried out by the first clutch apply relay valve switching to the fail position. The first clutch apply relay valve inputs the engagement pressure of the hydraulic servo from the linear solenoid valve when in the normal position, and is locked in the normal position. Thereby, while the first clutch is engaged, the second brake apply control valve can be switched by the signal pressure of the solenoid valve.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.