Operation method for at least one form-locking shifting element of an automatic transmission before start-up of an combustion engine

US8734282B2 · kind B2 · utility

Assignee

• ZF FRIEDRICHSHAFEN AG · DE

Inventors

• Ruben Cuppers · Schallstadt, DE
• Thilo Schmidt · Meckenbeuren, DE

Key dates

• Filing date: Apr 12, 2011
• Grant date: May 27, 2014
• Expiry date: Nov 24, 2032

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T74/20018
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A method of operating at least one form-locking shifting element of an automatic transmission integrated in a drivetrain which comprises an oil pump that can be driven mechanically by an internal combustion engine and an auxiliary oil pump that can be electrically driven, before start-up of the internal combustion engine. The method including the steps of recognizing the start-up of the combustion engine and, when a start-up of the combustion engine is recognized, controlling the electrically driven auxiliary oil pump and the at least one form-locking shifting element such that, directly after the generation of a defined rotational speed difference of the at least one form-locking shifting element by the internal combustion engine, the at least one form-locking shifting element is engaged.