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1. (WO2011157477) METHOD FOR ENGAGING AT LEAST ONE SPEED-INCREASING OR SPEED REDUCTION STAGE IN A TRANSFER BOX

Pub. No.:    WO/2011/157477    International Application No.:    PCT/EP2011/057112
Publication Date: Dec 22, 2011 International Filing Date: May 4, 2011
IPC: F16H 61/08
F16H 61/04
Applicants: ZF FRIEDRICHSHAFEN AG
MAURER, Markus
Inventors: MAURER, Markus
Title: METHOD FOR ENGAGING AT LEAST ONE SPEED-INCREASING OR SPEED REDUCTION STAGE IN A TRANSFER BOX
Abstract:
Proposed is a method for engaging at least one speed-increasing stage (H) and/or at least one speed reduction stage (L) in a claw-shift transfer box (VG) in a drivetrain of a vehicle having a drive engine and a shift transmission (SG) that can be shifted under load, wherein the transfer box (VG) is shifted into the neutral position (N) and, after the synchronization, is shifted into the speed-increasing stage (H) or into the speed reduction stage (L). According to the invention, during the synchronization, the shift transmission (SG) is braked or accelerated, by the actuation of at least one additional shift element, such that the output rotational speed (n_SG) of the shift transmission (SG) is aligned with the output rotational speed (n_VG) of the transfer box (VG) multiplied by the target transmission ratio in the transfer box (i_VG).