Hydraulic control apparatus for automatic transmission
US8182397B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 25, 2009 |
| Grant date | May 22, 2012 |
| Priority date | — |
| Expiry date | Jan 18, 2031 |
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 includes a first solenoid valve, a second solenoid valve, a third solenoid valve, a preliminary shift speed switch valve, and an oil pressure supply switch valve, which is switched between a normal-state position where the first, second, and third working fluid pressures can be supplied to the hydraulic servos of the first, second, and third friction engagement elements, respectively, and a failure-state position where the first and second preliminary oil pressures can be supplied to the hydraulic servos of the first and second friction engagement elements, respectively, and a line pressure can be supplied to the hydraulic servo of the third friction engagement element, during a failure that causes de-energization.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.