Hydraulic control apparatus of automatic transmission
US8430794B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 2011 |
| Grant date | Apr 30, 2013 |
| Priority date | — |
| Expiry date | Nov 26, 2031 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2061/1292
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic control apparatus of an automatic transmission which can supply a hydraulic oil pressure to one or more hydraulic servos of frictional engagement elements at a failure time when a de-energized condition is attained. The apparatus includes a normally closed type first solenoid valve for generating the hydraulic oil pressure, and a normally open type second solenoid valve for outputting a first signal pressure for adjusting and controlling an oil pressure to a line pressure; a signal output device for outputting the line pressure or a modulator pressure. The line pressure is reduced to a certain pressure, as a second signal pressure at a normal time, and causes the second signal pressure not to be output at the failure time; and an oil pressure switching device switchable between a normal time position in which the hydraulic oil pressure from the first solenoid valve can be supplied to the hydraulic servo, and a failure time position in which the input line pressure is supplied to the hydraulic servo, is switched to the normal time position by the first signal pressure and second signal pressure, which are input opposed to each other, being input, and switched to the fail…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.