Method for the operation of a transmission device in a vehicle drive train, comprising at least one form-fitting shifting element and multiple frictionally engaged shifting elements

US8989974B2 · kind B2 · utility

Assignee

• ZF FRIEDRICHSHAFEN AG · DE

Inventors

• Jörg Arnold · Markdorf, DE
• Valentine Herbeth · Friedrichshafen, DE
• Georg Mihatsch · Gettorf, DE

Key dates

• Filing date: Nov 7, 2011
• Grant date: Mar 24, 2015
• Expiry date: Dec 6, 2031

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16H2306/46
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

When a request is made to change gears, the form-fitting shifting element being disengaged, for the requested gear change, is disengaged at a predefined target disengagement moment following the target disengagement moment. When the gear is actually changed, an actual disengagement moment is determined based on when the form-fitting shifting element begins disengaging and a transmission operating state variable. If there is a deviation between the actual moment and the target moment of disengagement, then the target disengagement moment is modified by a time value, and the moment when the form-fitting shifting element begins to be actuated is shifted in time in relation to the target moment of disengagement and/or actuation of the shifting element to be connected is adjusted to a determined characteristic of the operating state of the form-fitting shifting element to be disconnected such that it is disengaged approximately at the target disengagement moment.