Transmission warm-up control strategy
US5803863A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 3, 1997 |
| Grant date | Sep 8, 1998 |
| Priority date | — |
| Expiry date | Mar 3, 2017 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2061/0209
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A transmission warm-up control strategy is provided for an automatic transmission used in a machine that is started or operated in cold conditions. When the operating value of the oil in the transmission is below a predetermined level, as sensed by a temperature sensor or a viscosity sensor, a controller turns on an indicator lamp, de-energizes all of the solenoid to the solenoid actuated valves, and holds for a predetermined period of time. The respective solenoids are incrementally energized and held for a second period of time while continuously monitoring the operating condition of the oil in the transmission. Once the operating condition of the oil is above the predetermined operating value, the indicator lamp is turned off and the system is returned to normal operating conditions. If the shift lever is moved from the park position during warm-up, all solenoids are de-energized and the indicator lamp is set to flash. The condition is held for the first predetermined period of time then the solenoids for the neutral clutches are energized and if the shift lever is not in the neutral position, the controller require that the shift lever be returned to the neutral or park positio…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.