Hydraulic control device for automatic transmission
US6056094A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 8, 1998 |
| Grant date | May 2, 2000 |
| Priority date | — |
| Expiry date | Jul 8, 2018 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2061/0253
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic control device controls hydraulic fluid for shifting an automatic transmission by a pressure control valve, and supplies operating hydraulic fluid diverted from the pressure control valve via a torque converter pressure passage to a lock up clutch of the torque converter. A lubrication passage which lubricates the automatic transmission is connected via an orifice to a torque converter pressure passage, and the pressure in this torque converter pressure passage is limited by a regulator valve to a predetermined upper limit value. Further, there is included a bypass valve which directly supplies hydraulic fluid from the torque converter pressure passage via the orifice to the lubrication passage when the pressure in the torque converter pressure passage rises above a predetermined pressure. On the one hand, at times of low speed vehicle operation, the engagement pressure for the lock up clutch is ensured by the orifice, while also at times of high load the amount of lubrication hydraulic fluid is increased by the bypass valve.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.