Engine braking control system for automotive automatic transmissions
US5105923A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 27, 1990 |
| Grant date | Apr 21, 1992 |
| Priority date | — |
| Expiry date | Sep 27, 2010 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2061/0237
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An engine braking control system for automotive automatic transmissions, comprises shift solenoids activated for executing a down-shift operation by selectively engaging or releasing frictional elements of a gear train, in response to engine braking requirements, sensors for monitoring a vehicle speed, an opening angle of a throttle valve, a depression amount of a brake-pedal, and a controller for controlling the down-shift operation on the basis of the signals from the sensors. The controller activates the shift solenoids for executing the down-shift operation only when the throttle opening angle is equal to or less than a predetermined threshold throttle opening angle, the brake-pedal depression amount exceeds a predetermined threshold depression amount and the vehicle speed is less than a predetermined threshold vehicle speed. The controller deactivates the shift solenoids when the throttle opening angle is equal to or less than the predetermined threshold throttle opening angle and the brake-pedal depression speed, derived on the basis of the signal representative of the brake-pedal depression amounts, exceeds a predetermined threshold depression speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.