Method for operating a drive train

US8509977B2 · kind B2 · utility

Assignee

• ZF FRIEDRICHSHAFEN AG · DE

Inventors

• Bernd Allgaier · Kreßbronn, DE
• Friedrich Tenbrock · Tettnang, DE
• Michael Gromus · Friedrichshafen, DE

Key dates

• Filing date: Jul 16, 2009
• Grant date: Aug 13, 2013
• Expiry date: Sep 21, 2030

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/62
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A method of operating a drivetrain of a motor vehicle which comprises a hybrid drive with a combustion engine coupled by a clutch to an electric motor. To start the combustion engine with the electric motor, the clutch is partially engaged to a slipping condition to deliver electric motor torque from a starting value, the torque transmitted by the clutch is increased to a first final value. If during this, the combustion engine begins turning, the break-away torque of the internal combustion engine is determined. If the combustion engine does not begin turning, the clutch is further engaged to a slipping condition starting from a second initial value, such that torque transmitted by the clutch increases linearly until the combustion engine begins turning, and the break-away torque of the internal combustion engine is determined from the clutch torque at which the combustion engine begins turning.