Method for operating an automatic gearbox on a motor vehicle

US7935024B2 · kind B2 · utility

Assignee

• ZF FRIEDRICHSHAFEN AG · DE

Inventors

• Matthias Winkel · Weingarten, DE
• Bertram Wengert · Markdorf, DE

Key dates

• Filing date: Jul 6, 2004
• Grant date: May 3, 2011
• Expiry date: Sep 20, 2025

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S477/903
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A method for the operation of an automatic transmission in a motor vehicle. The downshifting of the transmission takes advantage of a braking action of a driving motor connected to the automatic transmission through a clutch, are terminated by the closing of a clutch during a compression phase lasting until the achievement of a predetermined threshold speed. For the improvement of the immediacy of the vehicle drive after the termination of the compression phase, the invention provides that at speeds less than the threshold speed, downshifting is carried out and is terminated with an open clutch.