Patent ID: 8870712
Filing Date: 2014-10-28
Classification: B60W,F16H,Y10T

Abstract:
1. A method of shift control of an automated group gearbox, the group gearbox having at least a multi-step main transmission (HG) and at least a two-step range group (GP) which is positioned, in a flow of drive, downstream from the multi-step main transmission, and the two-step range group (GP) is connected with the multi-step main transmission via a main shaft ( 5 ), an input shaft ( 4 ) of the main transmission (HG) is either drive connected or drivingly connectable with a drive device ( 1 ), the main transmission (HG) and the range group (GP) have synchronization devices (SP 1 , SP 2 , SP 3 , SP 4 ) with shift clutches, the synchronization devices (SP 1 , SP 2 , SP 3 ) of the main transmission (HG) are each shiftable to three shift positions comprising first and second shift positions for engagement of two respective gear ratio steps and a third shift position being a neutral position, at least one synchronization device (SP 4 ) of the range group (GP) is only shiftable to two shift positions for engagement of two respective gear ratio steps and in which during a range shifting, in each of the main transmission (HG) and in the range group (GP), a change takes place between the two gear ratio steps, the method comprising the steps of: initiating a gear shift in the group gearbox which comprises a shin in the range group from one gear ratio step directly to another gear ratio step; shifting the main transmission to neutral; simultaneously initiating synchronization of the range group (GP), and synchronization of a rotational speed of the input shaft ( shifting a new gear ratio step in the main transmission after the rotational speed of the input shaft of the main transmission reaches the target rotational speed, and either after the synchronization and shifting of the gear ratio step of the range group (GP) or independently from a current synchronization condition of the range group (GP).