Method for shifting a neutral state of an automatic multi-stage transmission
AssigneeZF Friedrichshafen AG
InventorsHans-Jürgen Schneider, Thomas John, Mario Bühner
Life of this patent
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Abstract
Method for shifting a neutral state of an automatic multi-stage transmission of a motor vehicle, where, to engage and to disengage gear stages of the transmission, shift couplings, at least one of which is equipped with a synchronizing device, can be actuated by a transmission actuator.
Claims10
A method of shifting an automatic transmission of a motor vehicle, the transmission having a plurality of gear stages, and shift couplings which can be actuated by means of a transmission actuator to engage and disengage the gear stages, at least one of said shift couplings being equipped with a synchronizing device, the method comprising:
- exerting a braking action on the transmission input shaft by at least one shift coupling to substantially stop rotation of the transmission input shaft due at least to drag torque;
- partially actuating the at least one shift coupling to partially engage a gear stage in a first operating state of the motor vehicle while the transmission is in neutral, and
- fully actuating the at least one shift coupling to fully engage the gear stage when one of a forward gear and a reverse gear is selected.
Dependencies are inferred from the claim text.