Method for operating a drive train

US8246509B2 · kind B2 · utility

Assignee

• ZF FRIEDRICHSHAFEN AG · DE

Inventors

• Christian Mittelberger · Ravensburg, DE
• Stefan Blattner · Weingarten, DE

Key dates

• Filing date: Sep 16, 2008
• Grant date: Aug 21, 2012
• Expiry date: May 1, 2029

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/72
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A method for operating a drive train of a motor vehicle. The drive train comprising a hybrid drive with an internal combustion engine and an electric motor, a transmission arranged between the hybrid drive and a drive output, and a clutch arranged between the internal combustion engine and the electric motor. The internal combustion engine is started by engaging the clutch only when the electric motor is providing drive power. In this situation when shifting gears in the transmission with interruption of the traction force, immediately after the gear change and during a load build-up phase of the shift operation, the internal combustion engine is started by the electric motor without traction force interruption. The clutch is controlled to partially engage to start the combustion engine and then it is completely disengaged before reaching a synchronous speed between the combustion engine and the electric motor.