Patent Number: 8,870,712

Title: Method for shift control of an automated group gear

Abstract: A method of controlling a shift of an automated group gearbox having a multi-step main transmission and a trailing two-step range group. An input shaft of the main transmission is driven by a drive device. The main transmission and a range group have synchronization devices with shift clutches. Each synchronization device, for the main transmission, has two shift positions for respective gear ratio steps and a neutral position and the range group synchronization device has only two shift positions to shift between two gear ratios steps. To accelerate range shifts, when synchronizing the range group, the main transmission input shaft is synchronized by controlling external synchronization aids to a target rotational speed at which either after the synchronization and shifting of the gear ratio step of the range group or independently from the current synchronization condition of the range group, the target gear ratio is engaged in the main transmission.

Inventors: Steinborn; Mario (Friedrichshafen, DE), Mair; Roland (Tettnang, DE), Schneider; Florian (Lindenberg, DE), Breuer; Jochen (Tettnang, DE)

Assignee: ZF Friedrichshafen AG

International Classification: B60W 10/00 (20060101)

Expiration Date: 2018-10-28 0:00:00