Transmission control to avoid gain switch during shift
US10408342B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 2017 |
| Grant date | Sep 10, 2019 |
| Priority date | — |
| Expiry date | Dec 27, 2037 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2059/147
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
In a transmission hydraulic control system, a gain control valve may be used to switch between a low gain and a high gain based on line pressure. Line pressure may be controlled as a function of turbine torque. If the gain of a holding element or oncoming element changes during a shift as a result of changing turbine torque, shift quality may degrade. If the gain is set low at the beginning of the shift, the controller limits engine torque to ensure that the line pressure is not increased beyond a level that would cause a gain switch. If the gain is set high at the beginning of a shift, the controller maintains the line pressure high enough to prevent a switch to low gain, even if turbine torque drops.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.